Twisted solenoids to check sprinkler line and H2o pressure in house went down

[Betsy Callahan]

Don't know what's going on. House was built in 1989. Recently a very weak flow to 2 ( of 4 ) sprinkler zones in back yard. I turned the solenoids at the sprinkler valves to see if it was a valve problem or a break in the line between valve and sprinklers in zones that had weak flow at the sprinkler heads. There is no bleeder screw or pressure valve on the rainbird DV-100 valves, I am pretty sure they are the originals, put in when the house was built. When I turned the solenoids counter clockwise ( one at a time, in each of the two weak zones ) the water shot out of the sprinkler heads at full force in both zones, maybe even stronger than full force. I then turned the solenoids back to what I thought was the off position, maybe I turned them too far in the clockwise direction. The water to the sprinklers stopped as expected, but I went inside and a family member was taking a shower and the water flow to the shower head was a trickle. What did I do? Also if I turn the solenoids and the water pressure is strong, that means there is no pipe flow problem right? I really don't want to dig up my back yard. When the automatic irrigation timer control box sends the electrical signal to the solenoids in the valves I get a very weak flow to the two poor flow zones. I have set it on manual and watched. I think I need to replace the diaphragm on the valve units or maybe the solenoids or maybe both, does that sound right?

Appreciate any advice. Thanks.

 

[WorthFlorida]

Irrigation valves solenoids only need about a quarter turn to cause water to flow. It is impossible to over tighten them since the tip of the solenoid bottoms out. It only seems that the low water flow at the shower would only be when the valve was open. Are you on city water or a well pump? The solenoids work on 24 volts ac and they are open or closed, usually nothing in between. When you look at this video, you’ll easily see how how simple it is. Some valves also have the bleed screw as you can see on the right half of the valve. Turning it and removing it will also activate the valve. It can be used to flush out the dome area.

Solenoids for irrigation valves are mostly standard. They are relatively low cost so replace one of them to see if the water flow returns to normal. Turn off the water supply and remove the solenoid, turn on the water for a few seconds to flush the threaded part of the solenoid location.

It is possible after thirty years that the valves need to be rebuilt if you can still get parts. Some models get discontinued.

 

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[Betsy Callahan]

Irrigation valves solenoids only need about a quarter turn to cause water to flow. It is impossible to over tighten them since the tip of the solenoid bottoms out. It only seems that the low water flow at the shower would only be when the valve was open. Are you on city water or a well pump? The solenoids work on 24 volts ac and they are open or closed, usually nothing in between. When you look at this video, you’ll easily see how how simple it is. Some valves also have the bleed screw as you can see on the right half of the valve. Turning it and removing it will also activate the valve. It can be used to flush out the dome area.

Solenoids for irrigation valves are mostly standard. They are relatively low cost so replace one of them to see if the water flow returns to normal. Turn off the water supply and remove the solenoid, turn on the water for a few seconds to flush the threaded part of the solenoid location.

It is possible after thirty years that the valves need to be rebuilt if you can still get parts. Some models get discontinued.

 

[Betsy Callahan]

Thank you for video and response WorthFlorida,

I have completely replaced the diaphragm and the solenoid on zone 3, and it works well. Home Depot has parts that fit, they are rainbird DV-100 irrigation valves, but there is no bleed screw, they must not have put bleed screws on them in 1989. I am on city water. I turned the solenoids to the position where the water flow through the valves just shuts off (stops completely ) but not any further, and the water pressure in the house is back to normal now. I don't understand why the pressure to the house dropped so much just by turning solenoids on 2 sprinkler zones.

When I manually turn on zones 5 and 6 at the automatic irrigation control box I get a very low flow at all sprinkler heads on those 2 zones. So I know the electrical signal is making it to the solenoids. But if I turn the solenoids on the valves for those 2 zones I get normal, maybe even heavier than normal flow. Does that likely mean that if I replace the solenoids and diaphragms on zones 5 and 6 that zones 5 and 6 will work normal again?

Thank you

 

[WorthFlorida]

I would change both diaphragm and solenoid and you’ll be good for a lot of years. The diaphragms are probably getting stiff and debris in the dump ports. Glad it worked out for you.

The low pressure period is the sprinkler system was wide open with two zones and the water takes the path of least resistance. At that time your city pressure might have dropped some.

FYI. This Love Forum does have an Irrigation & Sprinkler forum. You’ll see it on the Home/Forums page toward the bottom.

 

[WorthFlorida]

I figured out why you had a complete drop of pressure at the shower. I'm guessing that the water main at your house tees off. The middle tee goes up into the home and the other end goes to your irrigation system. Essentially from the main supply 3/4" pipe to your irrigation system is a straight pipe. The shower faucet is open. When you opened both irrigation valves, water was flowing so fast past the tee that the water pressure in the main drops. Because the faucet was opened it allowed air to enter at the shower head as the water going into the home was sucked or drawn back because it was at a higher pressure. This how a "jet" pump works. A percent of the water is pumped through an orifice at a high flow rate to cause a low pressure area. This lower pressure allows water from the well that is at a higher pressure to be drawn into the pump. When you have just one zone flowing the flow rate is low enough not to draw water from the home.

 

[Betsy Callahan]

I figured out why you had a complete drop of pressure at the shower. I'm guessing that the water main at your house tees off. The middle tee goes up into the home and the other end goes to your irrigation system. Essentially from the main supply 3/4" pipe to your irrigation system is a straight pipe. The shower faucet is open. When you opened both irrigation valves, water was flowing so fast past the tee that the water pressure in the main drops. Because the faucet was opened it allowed air to enter at the shower head as the water going into the home was sucked or drawn back because it was at a higher pressure. This how a "jet" pump works. A percent of the water is pumped through an orifice at a high flow rate to cause a low pressure area. This lower pressure allows water from the well that is at a higher pressure to be drawn into the pump. When you have just one zone flowing the flow rate is low enough not to draw water from the home.

I think you are correct. There is a set of pipes and a round faucet at the front of the house by the garden hose and I think if I twist the faucet, it will shut off water to the sprinkler system only, but not the house. I have not tried it because I am afraid if the faucet breaks, I have a bigger mess on my hands. The faucet is really hard to twist, I have tried with my bare hands and it doesn't seem to move either way, so when I want to shut off the water to the sprinklers, I just do it at the street and tell my family we don't have water for a little while. Thanks also for the tip about the sprinkler/lawn forum, I didn't know about it but I checked it out and from now on I will post to that forum for those types of questions.

Replaced the solenoid and diaphragm on zone 5 last night in the dark. I am going to connect the wiring today and see if it works. You were right, the old diaphragm must have been the original, it was warped, had some kind of solid ( ?calcium ) build up all over it, and the design was slightly different than the new replacement I got at home depot. It was 2 separate pieces, not like the one piece rain bird replacement diaphragm. I found it was less likely to leak if I used the original 6 screws to seal down the bonnet compared to the new 6 screws that came with the replacement diaphragm. I think the older screws were made out of a higher quality, more durable metal than the new ones that came with the new diaphragm.

Thanks for your help WorthFlorida, I think I can make it work now. Happy Easter.