lawn sprinkler control unit repair

Wondering if this is the right group to ask questions about automatic sprinkler system control unit repair?

Reply to
pak
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I saw one (don't recall the brand) that would also go completely brain dead if the backup battery went bad. But it sounds like you should clean out around the values as a first step...

Reply to
AZ Woody

When on turned on control unit in the garage (had been shut down for winter) all seemed fine, programed it like I do each spring, except when I used the control unit to activate a sprinkler head, the unit went dark. So I went outside and opened the box in the ground where the wires are hooked to the valves. What I found is somehow the box had filled up with wet dirt and covered all the valves and wires. Could the wet dirt have caused the inside unit to short out? Do you think if i dig out the valves and let them dry out the inside unit might work again?

Reply to
pak

The control heads are so cheap that it rarely pays to repair it unless it's a simple problem.

From:pak snipped-for-privacy@comcast.net

Reply to
BruceR

One way the box fills up with wet dirt is when a gopher tunnels along your pipe trench and moves the spoils into the valve box. I have seen them sever the wire flush with the solenoid body. They could also have created a short circuit, which would trip a breaker or blow a fuse in your control unit.

Clean out the dirt and verify that the connections are sound. Perhaps also measure that solenoid at the control box to verify that the resistance is comparable to the other solenoids, I think in the range of 20-50 ohms. (Put ohmeter between common and valve when watering is not active.)

Reply to
George Pontis

What is broken? A device model number might be needed along with failure symptoms. My local OSH store carries parts for the Lawn Genie controller.

Reply to
Jack Ak

Yes! That's the first thing to do - clean everything up and dry it out. Check all the connections and waterproof them using gel caps (from Home Depot in the sprinkler section). Then check the fuse on the control unit and replace if needed and test.

From:pak snipped-for-privacy@yahoo.com

Reply to
BruceR

thanks to all for the great advice. give me a few days to get it dug out, and I may have more questions. BTW: I do have a gopher/mole problem, so that may very well be what happen, them tunneling into the valve box.

Paul

Reply to
pak

Gophers love lawn grubs. Put down chemicals to control grubs and the gophers will go away.

Reply to
Robert L. Bass

OK, got the valve box all cleaned out. There are 5 valves, each with a colored wire and a black wire which I guess is the common. All the connections in the valve box that were under dirt are just connected with wire nuts, but all wires seem intact and still connected. The fuse in the control box is blown. The advice here was to check all connections and then waterproof with gel caps. Can some one explain how gel caps work or what I do with them? are wire nuts sufficent for this application? Also George suggested " measure that solenoid at the control box to verify that the resistance is comparable to the other solenoids, I think in the range of 20-50 ohms. (Put ohmeter between common and valve when watering is not active.)

Could you explain that a little further? I assume all the control valves are soleniod operated. Not sure how to measure soleniod at control box. Am I looking to see if one of the valves has shorted out? Need a little more qdvice on the trouble shooting path.

Thanks Paul

Reply to
pak

Reply to
pak

Bruce- hate to keep asking questions, but ....just want to be sure I understand

1) unscrew the solenoid from the valve body? 2) re: your last sentence, how do I check solenoid and wires after they are disc>No, check for shorts with the power OFF! Changing the solenoid is
Reply to
pak

The gelcaps are plastic tubes filled with a waterproof gel. You stick the wirenutted connection into the gel and close the top. That keeps water out of the connector. There may already be corrosion in the wirenuts so replacing them (cutiing back the wires beyond the corrosion) will give you a clean, tight connection. To check for shorts from the control box, put one test lead on the common terminal and then touch the other lead to each screw terminal. If you read 0 ohms there's a short in a solenoid.

From:pak snipped-for-privacy@yahoo.com

Reply to
BruceR

No, check for shorts with the power OFF! Changing the solenoid is simple. Clip the wires and just unscrew it (turn the water off). The new one (available at your local home center) just screws in and you hook up the wires (it's 24 VAC so there's no polarity to worry about). If the same brand as your valve is not available, that's OK as they're interchangeable. Rainbird, Toro, Orbit, Lawn Genie, etc. all use the same thing. Bring the old one with you just to be sure. Remember, if you find a short from the panel it might be the wiring rather than the solenoid. If you find a short, disconnect the wires to the solenoid and check the soleniod and the wires to see where the problem is.

From:pak snipped-for-privacy@yahoo.com

Reply to
BruceR

Yes, just unscrew the black soenoid from the valve body if it indeed needs to be replaced. If you disconnect the solenoid wires from the wires going back to the panel, you then put your meter across the two solenoid wires and see if theres a short. Next, put the solenoid wires aside and put the meter across the common and the other wire going back to the panel and see if there's a short.

From:pak snipped-for-privacy@yahoo.com

Reply to
BruceR

OK, becasue all connections in valve box looked very old and worn, I undid all them.

1) tested each of the five solenoids, all but one read between 22-24 ohms, so I assume they are good. The fifth read infinity, so I assume that one is bad, correct? 2) At the vavle box cheched each of five colored wires to the common, each read 0-2 ohms, not sure what that means? Help 3) Then measured each colored wire terminal at control box to the common terminal, each read 0-1ohm. See aboverequest at item 2.

I am learning a great deal in this project and really appreciate your ongoing help.

Paul

Reply to
pak

Probably correct.

If you didn't disconnect the leads from the controller before checking, please do so. If you did and got those results the circuits are probably shorted.

It depends on the controller model.

Reply to
Robert L. Bass

So I will be cheching the colored wires to the common while they are not connected to anything on either end?

What resisitance does a piece of wire show if it's good. Probably depends >

Reply to
pak

For a reasonable run to the valves expect to see from 0-4 Ohms, depending on the condition of the system if the wire is shorted. You can check the resistance across the valves with no wires connected to get a base reading if you like.

My sprinkler valves are wired with 18-gauge copper. Unfortunately, the wires are only a few inches below grade and the gardener cuts them on a regular basis. Last month we asked him to replace a shrub in the hedges along the pool cage. He took out the sprinkler system and two of my phone lines. When I returned from Brazil the first thing I noticed was that my front lawn was beginning to resemble northern Iraq. I tried to call the gardener to ask him to come check the sprinkler system and there was no dial tone. :^(

Reply to
Robert L. Bass

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