about our blog:
This post covers troubleshooting of the station valving of a sprinkler system, including control wire issues and controller malfunction. The content of this site is from my personal experience installing and repairing automatic irrigation systems. Send me an e-mail if you have a comment. Thanks! Note: This post is only intended as a handy reference for my customers, and not as a replacement for professional irrigation service. If you choose to repair your own sprinklers, you use this information at your own risk. Accidents from unexpected water pressure, or pipe solvent mishaps, can result in eye injury. It is strongly recommended that safety glasses are worn at all times, and that you stay within your own level of expertise when working around electricity.
remote control valve
(The early part of this post might seem a little preliminary for those with some sprinkler experience, but it never hurts to revisit the basics!)
Also known as a station, zone, or solenoid valve, an automatic lawn sprinkler system will include a remote control (rc) valve for each watering station. Each watering station is composed of a group of sprinkler heads plumbed to that remote valve. When a station is activated from the clock, the signal is sent via a pair of field wires to the connected `solenoid,` which opens the valve hydraulically, thus allowing the water source to flow downstream to those linked sprinkler heads.
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| solenoid valves in manifold |
where valves are located, and why
Unless you have installed several sprinkler systems (not just your own), the logic behind a contractor`s choice of valve location might seem puzzling.
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| isolated valve in box |
To a homeowner searching for a bad solenoid, it might have made more sense to centralize the valving at a single location. On some systems, the valves may very well be plumbed in that configuration.
However, for a contractor, it`s usually more practical to route a single `main` supply pipe, connecting the solenoid valve where it intersects each watering station about the property.
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| valves grouped at single location |
remote vs `grouped`
Valves grouped in a manifold will require a separate `feeder` pipe from each valve routed to the watering station it controls. On a larger system, this arrangement might require excessive plumbing in a shared ditch, as well as, larger initial pipe sizing.
There are, in fact, many scenarios where grouping valves would be preferable. I have installed systems on properties where horses might be grazing, or heavy equipment would be used to maintain the grounds. On those jobs, I chose to place the valves together at a protected location.
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| isolated valve, connected to main-pipe routed through watering station area |
valve accessibility
More often, valve placement isn`t given that much forethought. For example, a particular spot may have been chosen only because that`s where the installer ran short of control wire.
Regardless, an installer`s good intention of choosing a service-friendly place for a valve is often countered by an unplanned landscape addition to follow. Of course, by function, the solenoid valve is `remote-control,` therefore accessibility isn`t crucial, and when needed, the installer knows it can be traced to `electronically.`
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| lacking an electronic locator, `probing` for valve with rod - good luck! |
For certain, where the valve was plumbed is not as important as finding it when a repair is required, especially if it`s `stuck` open.
If you`re `poking` the ground hoping to strike it, keep in mind that occasionally a valve gets buried without an access box, or at least, with a lid that doesn`t reach the surface.
Unless you`re fortunate enough to have been provided an as-built diagram pinpointing the solenoids, with current amendments included, location equipment is needed to find the valve. Scroll down below to read `locating a solenoid valve or wire.`
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| proper `zoning` is essential to properties with varied water requirements |
watering `zones`
Typically, many `builder` systems installed on new properties are valved economically based on maximum flow capacity. To reduce costs, the installer will minimize the controller size required by reducing the number of water stations.
It`s likely that the existing system design won`t fit any future amendments to the landscape. Custom water scheduling of areas with different sun exposure, plant materials, or drainage issues will require separate valve control.
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| This strip was valved with a sunny area requiring more frequent water |
If satisfactory results are expected from the system, any unrelated watering areas will need to be `split` with additional valving and a controller upgrade if needed.
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| programming capability is ineffective if system isn`t valved for it |
Over watering one connected area to meet the requirements of another will not only waste water, and money, but will affect the quality of the landscape, and might possibly aggravate structural problems of the house. Read my blog on watering for more info.
how a solenoid valve works
the electrical part
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| electro-magnet |
When a wire carrying electricity is twisted into a coil, it is called a solenoid. The solenoid connected to your sprinkler valve is an electro-magnet. The electrical energy is converted into a linear, mechanical motion that will operate the valve hydraulically.
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| solenoid |
When your sprinkler controller sends electric current through the coiled winding of the solenoid, it creates a magnetic field that reaches out in expanding circles.
The magnetic field twists with the coiled wire, causing the magnetic field lines to concentrate inside the coil. This creates a magnetic effect inside that draws the spring-loaded, metal plunger pin, up inside the coil tube.
the mechanical part
A solenoid valve has two chambers, an upper and lower, separated by a spring-loaded rubber diaphragm. Although the `spring` helps push the diaphragm closed, the valve stays closed because the upper chamber is about two times bigger, with a larger surface area of water pressure pushing down on the diaphragm from above.
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| diaphragm filter on RAINBIRD valve |
When the solenoid is energized, the plunger pin is drawn up from it`s seat, opening a small port, which allows water from the top chamber to exhaust downstream.
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| RAINBIRD solenoid |
Because the force on the top of the diaphragm has been relaxed, the water pressure in the bottom chamber pushes up on the diaphragm, allowing water from the source to flow downstream to the sprinkler heads.
When the solenoid is de-energized, the exhaust port is sealed by the released plunger. The top and bottom chamber water pressure will now equalize because of their connection through either a metering port, or a `bleed hole` in the diaphragm, closing the valve.
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| metering rod on K-RAIN valve |
Some valves have a metering rod that slides through the center of the diaphragm to keep this port clear. Valves with a bleed hole in the diaphragm may have a small filter to strain water entering the top chamber.
`stuck-open` valve
When a valve is slow to close, or `sticks` open, it is either due to a `worn` diaphragm, or debri is trapped in the metering port of the diaphragm, around the plunger pin, or between the diaphragm and it`s seat. Read my blog my sprinkler valve won`t shut off for more info.
Understanding how this valve functions may give you the option of fixing and cleaning, rather than plumbing a new part. Obviously, any mechanical problem would be resolved by replacing the whole valve, however, an electrical issue can be anywhere between the clock and the solenoid. solenoid valve circuit
One wire connects individually to a station terminal at the clock. The other wire returns back to the common terminal.
All the other station valves will have one lead connected to that single common return wire, and the other lead as an individual connection to a corresponding station terminal at the clock for separate control.
`master` solenoid valve
Some systems may also include a solenoid valve at the water source, which operates simultaneous with each individual watering station solenoid valve.
If this valve malfunctions, it would prevent system operation by preventing water flow to the station valves. Either an electrical or mechanical issue can be the problem.
If this valve malfunctions, it would prevent system operation by preventing water flow to the station valves. Either an electrical or mechanical issue can be the problem.
the purpose
Since water flow from the master valve is controlled by the clock, any other leak or breakage that exists downstream shouldn`t be constant. If the master valve is functioning properly, a loss of water would only occur while any station valve was activated.
Unless activated from the controller, a master valve would prevent constant flow downstream of the water source, therefore, it can be a safeguard in case a station valve should `stick open` mechanically.
However, the `bad` valve will stay operating alongside any other station valve while it is activated, either automatically or manually from the clock.
However, the `bad` valve will stay operating alongside any other station valve while it is activated, either automatically or manually from the clock.
On some systems, a master valve may be installed in conjunction with an `atmospheric`backflow preventer valve (explained later) or as part of an automatic winterization.
do I have a master valve?
Check to see if there is a wire lead connected at the `MV` or `PUMP START` terminal inside the clock panel. This connected lead, alone, doesn`t necessarily mean there is a `functional` master valve at the water source.
To verify you have a `working` master valve at the water source, disconnect the lead from the MV terminal and activate any watering station from the clock. If your not getting water flow, the master valve is doing it`s job.
By using the `resistance` setting of a volt-ohm meter, you can check for the existence of an `intact` solenoid at the end of any wire lead in question. From the clock location, the disconnected control and common wires of the master valve, or any station valve, can be tested with the meter to check for the resistance reading (20 - 60 ohms). You can also test master valve function at a station valve location. Assuming you have checked that the double-check valve is open, it will be evident there is a master valve if there isn`t water flow to `manually` activate a station valve with the bleed screw or lever.
where to start troubleshooting
learn all you can from the controller, before proceeding
Verifying whether you have partial system function, or none at all, will determine if your next move is to step back and check the water or electrical supply source, or to proceed ahead and locate a problem beyond the controller.
two devices that can affect entire system
testing a solenoid valve circuit
Using a volt-ohm meter, set at the `resistance` setting, you can check the condition of the valve circuits from the controller.
When I do a sprinkler check up on a property for the first time, I always do a resistance test on the valve circuits. It`s quick, easy and it will tell you a lot about what`s going on with the system.
Regardless of whether all stations are now activating, a valve circuit with a reading just outside the expected high or low range could signal a future problem from a deteriorating solenoid or wire connection.
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| look for programming error, and check functionality |
Verifying whether you have partial system function, or none at all, will determine if your next move is to step back and check the water or electrical supply source, or to proceed ahead and locate a problem beyond the controller.
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| test power in, power out, and wire continuity to valves |
(To troubleshoot a problem with the controller itself, including a `blown` fuse or an `error` display on the screen, scroll to the bottom of this post.)
Activating from the controller, if at least one or more of your sprinkler stations are visually operating correctly, then obviously, both water and power output are present for the system, and you can proceed to `test the solenoid valve circuits` (see below).
no valves operate, but circuits test `good`
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| testing AC at controller plug-in |
In this instance, the next step is to verify that approximately 120 VAC is available at the controller plug-in. A clock`display` on the screen is not necessarily an indicator that the controller is receiving AC power. The display could be provided by the battery back-up, despite power loss.
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| is the water source valve open? |
If you do have available 120 AC, you should activate the controller and test for approx 24 VAC output at any station valve output. If the controller checks out, I would verify that all water source valves for the system are fully open (when I first pull up to the curb on a repair job, I may check this first)
two devices that can affect entire system
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| rain-freeze sensor `clipped` to gutter |
If your system has a master valve, either a wire issue, or a mechanical problem with the valve itself, would prevent water flow to the station valves, thereby preventing operation of the entire system.
Many systems also include a rain freeze sensor that is connected `in-series` with the common wire. By function, or malfunction, this device can interfere with complete system operation as well. When I arrive at a repair job where the homeowner told me nothing works, and I see there is a rain-freeze sensor, it`s one of the first things I check.
testing a solenoid valve circuit
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| testing with a volt-ohm meter |
Using a volt-ohm meter, set at the `resistance` setting, you can check the condition of the valve circuits from the controller.
When I do a sprinkler check up on a property for the first time, I always do a resistance test on the valve circuits. It`s quick, easy and it will tell you a lot about what`s going on with the system.
Regardless of whether all stations are now activating, a valve circuit with a reading just outside the expected high or low range could signal a future problem from a deteriorating solenoid or wire connection.
When you perform a resistance test on a solenoid valve from the controller, it gives you the complete `health` of that circuit, including control and common wire continuity to the valve solenoid, connection of all splices, and the condition of the solenoid itself.
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| testing resistance of master valve solenoid with disconnected control wire and common |
After you have checked the circuits from the controller,and the `problem` valve is then located, it isn`t necessary to test for 24 VAC at the solenoid location. If the circuit tested `good` at the clock, that verifies that a correct path for electricity exists, and the solenoid and it`s connectors are intact.
However, If the station valve still won`t activate, it`s likely that the valve itself is mechanical bad, and will need replacement.
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| check wire connection at terminal |
look at the big picture
Whenever you have one station that won`t operate, you should always test all of the other stations as well. There may be another station that isn`t operating you`re not aware of. In addition, multiple problems are often related, and you should always troubleshoot the system as a whole.
reading the test results
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| This `shorted` HUNTER brand solenoid tested 4.5 ohms |
With the meter on the ohm setting, test the resistance between the disconnected station control wire and common wire of the watering station in question. A `good` solenoid valve circuit will test between 20 - 60 ohms, based on most valve solenoids available. It`s not uncommon for a solenoid to test outside that high or low range, and still be operational. However, If you do get a reading on the fringe, it could be a sign of a deteriorating solenoid or wire connection.
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| This new HUNTER brand solenoid tested 25.2 ohms |
With roughly one ohm added to approx 100` of field wire, most of that resistance will come from the long, coiled winding of the solenoid. Different brands of solenoid will vary in their resistance. For example a RAINBIRD solenoid may have a resistance of 45 ohms, while an HUNTER might measure 25 ohms.
Not common practice, but two solenoids connected on the same circuit will test approximately half the resistance of one.
single valve won`t operate, but circuit OK
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| replacing solenoid valve |
Before you search for the valve in question, first verify the water source valve is open by operating another station.
station not operating, but is water flowing?With the problem station activated from the clock, `walk` and inspect the watering area the problem valve controls. Verify that an unseen broken pipe or head isn`t creating a pressure drop that only makes it `appear` that the problem valve isn`t activating.
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| water loss from broken sprinkler line escaping out drain, unseen |
`mystery` watering station
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| sub-surface watering |
I have serviced several systems that had a station valve dedicated to filling a swimming pool or water feature. If you`re unfamiliar with the system, it`s worth checking if flow is registering at the water meter while a `mystery` station is activated.
Keep in mind also, that some systems may have a station valve connected to `sub-surface` irrigation. Now commonly used in narrow parkway strips or medians, and unlike coventional `spray-heads`, this type of watering would operate out of view. Read my blog on sprinkler heads
high or low resistance reading
If the resistance reading is high, over 80 ohms, this indicates the possibility of a bad splice at one of the solenoid leads, a partial connection from a broken control wire, or current is being lost through `skinned` insulation on the wire.
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| meter display shows `open` circuit, or no continuity. probably a cut wire, failed splice, or broken solenoid coil |
A low reading, less than 10 ohms, signifies a short circuit. Typically, it`s a shorted solenoid, but it could also be caused by a `skinned` station and common wire touching. If the solenoid tests OK at the valve location, it`s possible someone may have dug into some sprinkler wiring.
A lower than expected reading could also mean there are multiple solenoids connected on the same circuit. Although more than one control wire lead connected on the same controller terminal would be an obvious clue, multiple solenoids could otherwise be connected at the valve location.
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| saturation around `leaking` connectors |
`fault scenario`
On occasion, I`ll run into a wire problem where the conditions that created the fault for the homeowner aren`t present when I`m on the property `testing`. Several times, I have arrived on a repair job where the homeowner was experiencing a tripped circuit breaker on their controller, and after testing the clock and performing a resistance check, I surprisingly found all circuits tested `good.` A solenoid that is functional, but just beginning to deteriorate, can create this problem. In that situation, the watering station may only fail intermittently. In the case of bare wire or `leaking` splices, it may be necessary for the surrounding soil to reach a point of saturation before the arcing occurs.
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| submerged solenoid valves. some splices were only `taped` |
A short test cycle from the controller may not always be enough to re-create the fault environment. In addition, solenoid valves, or the leaking wire connections, may not be located inside the watering area they control.
If there isn`t a single `suspect` watering station to isolate, it may be more practical for a repairman to ask the homeowner to monitor the system during a full programmed watering cycle, then take note of which station registered an `error` on the controller screen.
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| testing resistance at solenoid location |
testing at the valve
Several of the wire issues illustrated in this post may require electronic location equipment, and probably a little experience along with it. To read more, scroll down below to `locating a wire or solenoid valve.`
If the solenoid valve in question has been found, disconnect the leads and test. If the resistance reading is `low` or `open`, replace the solenoid. Install new water-proof splices at the wire connections.
valve won`t open
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| manual operation of RAINBIRD valve |
Assuming the water source has been verified, if the solenoid coil is intact and receiving the proper voltage, but the valve still won`t activate, obviously there is a mechanical issue with the valve itself.
When a valve won`t open hydraulically, it`s usually because the upper chamber can`t exhaust downstream.
This is more likely due to a port obstruction, or less commonly, a bad diaphragm or a `stuck` solenoid plunger (typically this happens in the `open` position, but free movement should be checked anyway). 
clogged ports?
clogged ports?
If you just installed a `slip-socket` valve, it`s possible pipe glue may have plugged the tiny exhaust port on the top, inside of the downstream socket. After shutting off the water source to the system, remove the solenoid and stick a straightened paper-clip down through the exhaust port hole.
Occasionally, I will run across a station showing lower than normal pressure, that `perks up`when you open the manual bleed screw. In this situation also, try cleaning out the exhaust port before you replace the valve.
Occasionally, I will run across a station showing lower than normal pressure, that `perks up`when you open the manual bleed screw. In this situation also, try cleaning out the exhaust port before you replace the valve.
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| flow control on Toro valve |
Most won`t, but if this station valve happens to have a flow control knob, make sure it is fully open. Try manually operating the valve by opening the `bleed plug` or lever.
If your system includes a master valve, you will first need to activate the problem station from the clock, or open the bleed plug at the master valve, before you manually open any station valve. If you`re still not getting water flow to the sprinklers, replace the problem valve.
circuit, valve OK, but no downstream flow?
A time or two, I have found a situation where someone, maybe the previous owner, has discontinued a watering station by either `closing` all the sprinkler nozzles on a circuit, plugging off all the heads, or by capping the downstream pipe from the valve.
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| are the nozzles open? |
Maybe they closed the heads to prevent undesired watering of an area, but it`s also possible that this was their solution to stop constant leakage from a `seeping` station valve. If the homeowner had some work done, a contractor could have capped the sprinkler pipe prior to new construction or paving. Unless it was evident, in order to verify a `cap` downstream, you would need to open the pipe on the output side to test the valve for flow capability.
cross or `short` in station wires
cross or `short` in station wires
The picture at right illustrates a location where someone has dug into sprinkler wiring, and `skinned` the control wires of station #1 and 2. A `cross` now exists between those two stations. Both stations will now operate together regardless of whether either station is activated individually from the controller.
Since station #1 and 2 are now crossed together, operating either station from the controller would trip the circuit breaker, because of the short at the common wire and station #1 control wire.
Remember, that in wet conditions, buried wire splices that are not waterproof can also cause a short or a cross.
some stations operate, some won`t
If someone digs into sprinkler wires, they may very well cut one, several, or all of of the station control wires, which would prevent each station valve affected from operating. Pictured left, when a hole was dug for a tree, the control wires for station valves # 3 and 4 were cut through. The insulation for station #5 control wire was `skinned, but the common wire was left intact.
for the homeowner, stressed landscape is usually the only clue
The contractor who dug this hole may, or may not, have been aware that these wires were cut into. Regardless, the hole was filled in without making repairs. Typically, the homeowner didn`t realize a problem existed until three weeks later when the grass started to turn brown.
Arriving at this property, I tested all stations at the controller location and found there wasn`t wire continuity for stations # 3 and 4. Station # 5 did show a resistance reading of 87 ohms, but a much higher reading than you would test from a `good` circuit.
When the homeowner called me for service, he had forgotten about the tree planted a month before, until afterwards, when I showed him the repaired wires.
`fault` in the common wire
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| this cut will isolate station 2, 3 and 4 from the controller |
A break in the common wire connection that separates any connected solenoid from the controller would prevent one or more stations from operating.
Like the picture left, most residential sprinkler systems will have all of the solenoid valves connected to a single common wire that is routed back to the controller. Any break, or failed splice, in this wire would prevent any connected solenoid from operating that was downline from the wire separation.
The illustration right points to the common wire splice at a station valve. If the solenoid wire lead `slips out` of the splice, this valve won`t operate.
If the common wire to the controller loses contact, it will prevent this valve and all station valves connected downline from operating. If only the common wire from the next station valve slips out, this valve will operate, but the valves downline won`t. Of course, if the solenoid wire lead splice at the control wire connection fails, it would only prevent this valve from operating.
common wire `opened`
A `hard-wired` rain sensor, pictured left, is connected `in-series` with the common wire. By design, it will interupt wire continuity to the station valves following wet weather. A failure of this device, or at it`s connections, would create the same scenario.  |
| wireless rain- freeze sensor kit |
The leads routed from a sensor may either be connected to the common wire inside the clock panel, or buried outside the controller location. The condition of any exposed wire routing should be inspected, especially where it may have been vulnerable to `weeder` damage.
Now more popular, many properties utilize a wireless sensor kit where a `receiver` is connected to the common wire at the clock, and a battery powered transmitter is clipped to a location exposed to weather.
`multiple` common wires
Some systems will have multiple common wires, each wire routed from a group of valves back to the controller. Other systems may have two common wires connected at the controller, each possibly routed from opposite sides of the property.
If the common wire routed between the controller and that group of valves is cut, it would only prevent those connected solenoids from operating without affecting solenoids connected to the controller by another common wire.
clue to partial system failure?
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| 3 multi-conductor cables, each with a common wire, routed from 3 groups of station valves |
Sometimes, inspecting the wire connections at the controller will give you a clue how some stations are linked together.
Examining the wires diagrammed left, if stations #7, 8, and 9 all stopped working, and it`s certain nobody dug into wiring, you might suspect that either the common lead for that cable slipped out of the orange wire nut, or the common wire splice at the first solenoid valve out from the clock failed.
If somebody has dug into wires, it`s possible that particular cable has been cut through, or at least the common wire in that bundle.
`fault` at wire transition
Some installers will splice the control wires from the field to a short run of `slimmer` multi-conductor cable, to make easier insertion through the wall where the controller is mounted.
These wire splices are typically, but not always, direct-buried just outside the wall. You never know if water-proof connectors were used or not, but since these connectors are buried, they are suspect.
clue to buried wire connectors These wire splices are typically, but not always, direct-buried just outside the wall. You never know if water-proof connectors were used or not, but since these connectors are buried, they are suspect.
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| `multi-conductor` cable |
Comparing the wire type inspected at one or more station valves with the control wires connected at the controller, will give you a clue that a wire transition exists somewhere.
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| control wire exiting garage |
A wire transition itself isn`t a problem, but it would mean that a connector had to be used between the two wires, where a fault would be more likely. If it isn`t direct-buried, it could be at a solenoid valve location inside an access box.
Don`t overlook where the control wires exit the wall of the garage into the ground. I have made a few repairs where, lacking conduit protection, the wires were cut into by a weed-whacker. Conduit that is broken should be inspected as well.
has someone been digging?
Troubleshooting wire problems on some systems can be a challenge, even for an experienced repairman. Because it`s safe low-voltage, field wiring isn`t required to be installed in protective conduit. Direct burial wiring is at the mercy of growing tree roots or anything that is stuck in the ground. Less than professional repairs are often made by individuals who accidentally dig into it.
about sprinkler wire
the old days
A few systems installed in the 1980`s through the early 90`s included 22 gauge `thermostat` wire that was not designed for direct burial, and was prone to oxidation.
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| `solid-core` 14 gauge wire |
Some contractors routinely used it because it was inexpensive, and it had several conductors in a compact cable. Having said all that, I have worked on several systems with thermostat wire that were installed over 30 years ago, and the connected solenoid valves are activating just fine.
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| `multi-conductor` UF 18 gauge wire |
Most systems installed now will have either solid core 14-18 gauge wire or multi-conductor UF cable, which is approved for direct burial. The white-colored wire is normally used to identify the `common.`
wire connectors
Many sprinkler wire problems can be avoided by using water-proof connectors at all splices. If unprotected, moisture can seep into a connector, corroding and eventually breaking the wire connection.The water-proof connectors, pictured left, are wire nuts filled with a sealant.
discard the old connector
discard the old connector
It`s recommended that you don`t re-use an old water-proof connector that has been removed. Some individuals will try to use a regular wire nut filled with pvc glue. This isn`t reliable, because the glue will `shrink` as it dries, possibly leaving a void inside the connector that moisture can seep into.
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| locating solenoid valve |
Individuals like myself, who repair sprinkler systems as a business, use location equipment for finding solenoid valves, as well as, cuts or large nicks in field wire. Without this tool, troubleshooting a wire problem on most systems would be, at best, impractical.
The locator I use is pictured below. In the kit, a lead from the transmitter box hooks up to the disconnected end of the wire your chasing. The ground lead connects to a stake stuck into the earth. The transmitter sends a signal along the wire that is picked up by the receiver, which is a hand-held `wand`.
In addition to a analog meter, the receiver also has a connecting head set that gives audio to the signal.
how a locator works
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| the locater kit I use |
When the wand is held directly over the wire your tracing, the signal received appears as a `null` or silence. If you move the wand away from the wire, you get an audible.The signal at the end of a broken wire will intensify before fading off as you move past.
When you swath across the coiled winding of a valve solenoid, the signal is intense and very audible.
When you swath across the coiled winding of a valve solenoid, the signal is intense and very audible.
A locator kit is expensive to purchase, not always available for rental, and it does require user experience to zero-in on what your looking for. Regardless, a locator is a valuable tool for a person in my business.A homeowner who prefers to fix his own system, might consider hiring a person with the equipment to locate all of the solenoid valves. The homeowner could then refer to the mapped locations in case a valve or solenoid ever needed replacement. It`s much more cost efficient to do this on one service call, rather than be charged to locate each valve individually as a problem arises.
`bypassing` a wire problem
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| `doubler` |
A device that many sprinkler contractors use to fix problems like these is sold as `add-a-zone` or `doubler.`
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| single control wire connected to two stations via `add-a-zone` link |
When needed, I have used both these mechanisms with good results. I personally prefer the add-a-zone, but the doubler has been around for many years. The cost of either kit, $90 +, can be justified if routing a new control wire would be impractical.
Either device will allow the independent use of two separate sprinkler stations from one pair of control and common wire.
An electro-mechanical device, the `doubler` switches from one of it`s two output leads each time the incoming AC power is turned off. Therefore, if the doubler is `split` between, say, station #1 and 2, the two zones will alternate each time they are shut down.
The `add-a-zone` will keep the same stations without the switch. For this reason, you may prefer this device over the doubler, particularly if the two stations linked together have completely different water duration requirements (such as sprays and rotors).
If you `re not correcting a wire issue, but just want to add an extra watering station, you will need an unused station terminal on your existing controller. Of course, routing a new wire might be the better permanent option whenever possible, and as handy as these `splitter` devices are, they will require replacement eventually.
no power output from controller
check the outlet
As stated earlier, a digital clock display is not a good indicator that the controller is receiving AC power. Regardless of a power loss, the back-up battery inside some controllers may provide the display. |
| reset button on GFCI outlet |
If you`re not testing approximately 120 VAC at the controller plug in, the main panel breaker for that circuit should be checked. It`s also likely that a controller located inside a garage is plugged into a GFCI outlet. If the controller plug-in outlet doesn`t have a reset button, it may be on another outlet inside the garage, or a neighboring bathroom, that is also linked on the same circuit.
test the transformer
However, if your not getting power ouput, you should test the transformer itself, before you write off the whole controller. Check the transformer where it connects to the clock. If you aren`t showing approx 24 VAC here, the transformer is bad.
If you are showing correct AC at this location, check the fuse inside the panel.
`blown` fuse
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| fuse location on RAINBIRD ESP clock |
The purpose of either fusible link is to protect the clock from a power overload caused by a short circuit in the field wiring or solenoids. The `suspect` sprinkler station would show a lower than expected resistance reading on your solenoid valve circuit test, as discussed earlier.
Clocks with an electronic circuit breaker will flash a `fault` or `error` message on the display screen to alert a problem. Clocks with replacement fuses will have a blank screen, or may display `PWR OFF` if the fuse blows.  |
| two types of controller transformers |
It is also important that the new replacement fuse is the one specified for your controller, not necessarily like the blown fuse you discovered in the clock.
Because a much higher amp-rated fuse was put in it`s place, the next time the clock was activated, the new fuse didn`t blow, but the fusible link in the transformer did. After he figured out the transformer was now bad, he went through two replacements before he gave up and finally called me.
bad controller?
If the transformer output tests `good` and all fuses are intact, but the controller still has a blank screen or erratic function, it`s likely the controller itself is bad and may require replacement. In many instances, there could be damage to the circuit board caused by a power surge, possibly from an electrical storm.
If your clock has taken a power surge, the screen display may `freeze-up,` appear jumpy and erratic, or just be blank. However, before you write off the controller, let it `power down` by unplugging it, and removing the back-up battery from the panel. Leave it off for a few minutes before restoring power, afterwards, you can re-enter your programming and try another test.
It`s important that you refer to the owner manual for your clock. Besides giving you the correct operating instruction for the device, the manual will include the location of the fuse and back-up battery, as well as, minor troubleshooting tips with the correct specs for replacement accessories. If you don`t have a manual, many manufacturers will have a website where you can download a copy for free.electro-mechanical clocks
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| electro-mechanical clock |
If a `worn` motor fails on the mechanical clock, the station dial will freeze up, preventing automatic advancement.
Note that this clock also has a `pop-in` fuse on the top right panel face. Check the fuse status before assuming that the clock is bad.
`dual` clock problems
Some larger systems may have the sprinkler stations split up on two or more controllers. The clocks are not always installed side-by-side and may be at different locations on the property. A previous owner may have extended the original system, and it may have been more practical to place the second clock closer to the added watering stations. On larger properties with many watering stations, installing two smaller capacity control boxes may be less expensive than a single, larger capacity clock.
offset watering
When multiple clocks are installed on a sprinkler system with a single water source, it is important that the watering schedules of either clock do not `overlap` each other. Two separate watering stations operating together may exceed the flow capacity, affecting residual water pressure and spray coverage. Regardless of whether there is very high pressure available for the system, exceeding `safe` flow velocities isn`t recommended, and could possibly lead to main pipe or fitting failure.offset watering
`shared` master valve
Another problem is possible when two or more clocks `share`, and power, a remote master valve. It is also important in this setup that the watering schedules are offset so that the clocks are not activating the master valve solenoid at the same time. Otherwise, one, or both of the clocks will trip their electronic circuit breakers or blow a fuse inside the panel. This issue can be resolved with program scheduling, but if either clock loses AC power, the default programming could place the system in a fault scenario. If it is known that two clocks will be utilized in a new system installation, it might be a good idea to have a separate master valve at the water source for each clock.
I have made several repairs to systems due to power surges caused by lightning strikes. More often, it`s primarily the digital controller on the receiving end of this damage, but other components including piping can be in the path of destruction.
Lightning damage is not always this evident and the effects may not be discovered until the system is tested. If you have a malfunctioning controller following a storm, you should verify wire continuity by testing the solenoids with a resistance check from the clock location.
Although no product is available to effectively protect against such a high level of energy, fortunately this much sprinkler system damage is extremely rare.
Big commercial irrigation systems, and golf courses, can afford to protect their expensive, extensive components with proper grounding technique, however, these methods may not be cost effective for smaller residential applications considering the comparative cost of sprinkler parts you are trying to protect.
`Battery` operated valves
Originally, these type of systems were utilized because either AC power wasn`t available or it wasn`t feasible to run power to where a sprinkler controller was required. My first experience with battery operated valves was years ago on a commercial job where we installed irrigation in center median strips. At this location, water was available but not electricity.
how it works
These `polarity-reversing` short pulses only need tiny amounts of power, which just require the use of small batteries and allow many operations before replacement.
In the photo of the controller, notice the `black` wire, which is routed to all valves as the `common` wire. The red wires are individual station control wires. If desired, the yellow leads shown can be routed to a weather sensor device. The latching solenoid leads are also distinguishable as red and black for connection to the correct field wire.
problems?
Like any conventional sprinkler system, battery operated valves are not without issues. At least with the older versions, it was possible for a latching solenoid to get `out of phase`, creating obvious problems if you reversed open and closed durations.
Batteries will need to be replenished, at least every season, and remote valves with an individual controller at the solenoid would need to remain accessible. When designing, field wire runs from the controller to the remote valve should probably be less than 100`, otherwise it could shorten battery life. Latching solenoids may also be more susceptible to internal debris than regular solenoids, which could cause `sticking` problems if the water supply wasn`t clean.
`hydraulic` systems
better utilization?
`two wire` technology
This type system is not new, and initially was available with a DC current supply, and not without it`s share of quirks and issues. Now much improved and operating with AC current, it`s fast becoming more popular with larger residential and commercial properties.
The obvious benefit of a 2 wire system is that it utilizes only one pair of wires routed from the controller to the station valving. This would greatly reduce the number of wire runs on a big project.
At each station valve location, a receiver switch, or `decoder`, is connected. The decoder mechanism gives each valve location a unique `address` which identifies it to the controller. A 2 wire system not only sends power to the solenoid, but also transmits data. When a station valve is activated either manually or automatically from the controller, a module installed at the controller sends a digital command signal to the decoder to operate that particular valve.
flexibility?
Probably the best feature of this system is the ability to expand with adding valving/ decoders anywhere along the 2 wire routing. This gives it an obvious advantage over a conventional system whenever routing new wires back to the controller location would not be practical.
conversion?
Of course this will change with time, but this current technology is still relatively new and there aren`t that many experienced techs familiar with this set up. Granted, whatever type sprinkler system you work on, there will always be unique `hassles` depending on who you talk to and that person`s skill level. Many irrigators like myself, who have installed and repaired scores of conventional systems are sometimes a little hesitant to convert away from the mechanism they have become familiar with. Regardless, one thing seems likely, 2 wire systems are here to stay and only to be improved on.
Read my other posts:
Lightning damage to your system
I have made several repairs to systems due to power surges caused by lightning strikes. More often, it`s primarily the digital controller on the receiving end of this damage, but other components including piping can be in the path of destruction. A tree is typically the striking point with the surge of electricity dissipating to the ground through the root system, or even the surrounding steel landscape edging. In a worse case scenario, this surge can shoot through sprinkler field wiring, destroy some connected solenoids along the way, and ultimately, `fry` the controller.
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| controller damage from surge |
I was recently called to a property where a tree took a lightning hit in the front yard. In addition to the damaged controller, this surge exploded a flood lamp under the tree and tossed it through the front window, fried four valve solenoids, vaporized 15 feet of sprinkler control wire, and caused the main pipe to blow out in two locations ten feet apart.
On this particular call, the `blank` controller was obvious to the homeowner, but water gushing out of the damaged piping was the immediate concern. At those breaks, I also discovered that the control wire was melted and terminated.
Lightning damage is not always this evident and the effects may not be discovered until the system is tested. If you have a malfunctioning controller following a storm, you should verify wire continuity by testing the solenoids with a resistance check from the clock location.
Although no product is available to effectively protect against such a high level of energy, fortunately this much sprinkler system damage is extremely rare. You are much more likely to encounter an indirect surge, that may do little more than scramble the controller display. In some cases, this might be corrected by just `powering down` and resetting the controller. Otherwise, replacement is required. Some of the better clocks available now include some good surge protection on the field side, as well as, on the incoming line. Again, this would only offer limited protection from surges other than direct strikes.
Big commercial irrigation systems, and golf courses, can afford to protect their expensive, extensive components with proper grounding technique, however, these methods may not be cost effective for smaller residential applications considering the comparative cost of sprinkler parts you are trying to protect.
`Battery` operated valves
The RAINBIRD valve kits we used, photo left, had a small programmable control box attached directly to each valve solenoid. The controller operated on a single 9V battery.
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| HUNTER battery operated controller on valve w/ latching solenoid |
The other type system commonly used now uses a battery operated controller installed at a central location, exactly like a conventional AC powered clock. Usually powered by two 9V batteries, this controller runs on DC current instead. Systems that use DC require that each valve has a `latching` type solenoid. This solenoid can be retrofitted on most conventional sprinkler valves of the same brand.
When a DC controller is activated, it sends a `pulse` to the latching solenoid, via the field wires, which pulls up the solenoid plunger pin. For a standard solenoid, an AC controller would have to provide a constant 24V power supply to hold the plunger up, but the DC latching solenoid is held up by the magnet at it`s base. When the latching solenoid is deactivated by the controller, another pulse is sent which releases the magnetic field on the plunger, thus closing the valve hydraulically just like a conventional one.
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| TORO battery operated controller |
In the photo of the controller, notice the `black` wire, which is routed to all valves as the `common` wire. The red wires are individual station control wires. If desired, the yellow leads shown can be routed to a weather sensor device. The latching solenoid leads are also distinguishable as red and black for connection to the correct field wire.
problems?
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| HUNTER latching solenoid |
Batteries will need to be replenished, at least every season, and remote valves with an individual controller at the solenoid would need to remain accessible. When designing, field wire runs from the controller to the remote valve should probably be less than 100`, otherwise it could shorten battery life. Latching solenoids may also be more susceptible to internal debris than regular solenoids, which could cause `sticking` problems if the water supply wasn`t clean.
`hydraulic` systems
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| `Moist O` Matic``controller - circa 1958 |
I have only had to work on a few of these systems over the years, two of which I was asked to convert to a conventional electric solenoid system. Hydraulic sprinkler systems have been around for a long time, and despite the fact that most of the old manufacturers stopped making the equipment, TORO still offers this product line.
A hydraulic system is different from a conventional system in that it uses water pressure to open and close the valve rather than an electrical solenoid. A supply tube from the water source is routed to the hydraulic controller. From the controller, tubing is routed individually to each remote hydraulic valve.
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The controller indexes the flow of water to each remote valve either manually or automatically. Simply put, to keep a valve `closed,` constant water pressure is kept on the supply tube to the valve. To open a valve, pressure is `released.` This type of hydraulic valve is referred to as a `normally open` valve. There are also `normally closed` hydraulic systems where supplied water pressure would open the valve instead.
pros?
Given some difficulty of troubleshooting this type of system, there are a couple of advantages that are noteworthy. A totally hydraulic system can operate without requiring an electrical supply or batteries. In areas that are prone to lightning strikes, such as Florida, a hydraulic system without any buried wiring might be a viable alternative.
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| TORO MONITOR II faceplate |
However, from my own experience, I will tell you that servicing these systems always required a lot of digging and searching.
cons?
Supply tubing can easily be damaged by digging or chewed through by burrowing critters. When a control wire is cut to an electric solenoid valve, the valve will stay closed, but when you cut into the supply tube of a hydraulic valve, it will stay open. In addition, a hydraulic valve can`t be traced to via the field wiring like a conventional solenoid valve.
Yes, those old hydraulic valves did contain some metallic parts, but trying to find them with a metal detector is at best hunt and peck. I have also seen water damage caused by leaking tubing that was routed inside a garage to the controller.
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| Hydraulic valve buried at remote location |
Hydraulic systems were always a great concept, but the problem with many systems is that they weren`t designed with serviceability in mind. For instance, it might have been preferable to group the valving together close to the controller, with shorter runs of supply tubing. Granted, that may not have been practical on larger properties, but neither would routing 100` of vulnerable rubber tubing to a remote valve buried without an access box.
Many contractors were applying the same mindset of remote center-feed valving that they had used installing electric solenoid systems.
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| TORO 250 series hydraulic valve |
modify or salvage?
Since there are only a handful of these systems left in the area that I service, in most cases I usually recommend conversion to either a conventional AC setup, or on some properties, switching to battery-powered remote valves. It`s also important to note that some of these old systems sometimes lack proper backflow prevention. Before you invest in refurbishing a hydraulic system as it is, it should be verified that your system is up to code with current city requirements.
`two wire` technology
This type system is not new, and initially was available with a DC current supply, and not without it`s share of quirks and issues. Now much improved and operating with AC current, it`s fast becoming more popular with larger residential and commercial properties.The obvious benefit of a 2 wire system is that it utilizes only one pair of wires routed from the controller to the station valving. This would greatly reduce the number of wire runs on a big project.
flexibility?
conversion?
Retrofitting a conventional system would be possible by utilizing any two of the routed existing conductors and connecting them to a decoder module. That connection would then become the new two wire path. Although several new controllers available can be converted to two wire service, there are universal decoder modules that could convert practically any controller.
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| decoders use milliamp current and servicing requires the proper test tools |
problems?
Of course this will change with time, but this current technology is still relatively new and there aren`t that many experienced techs familiar with this set up. Granted, whatever type sprinkler system you work on, there will always be unique `hassles` depending on who you talk to and that person`s skill level. Many irrigators like myself, who have installed and repaired scores of conventional systems are sometimes a little hesitant to convert away from the mechanism they have become familiar with. Regardless, one thing seems likely, 2 wire systems are here to stay and only to be improved on.
Read my other posts:
