SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Quoted from "ScubaNana"

hello! First of all sorry for my poor english, but i heven't use this language since a long time
I have similar problem. One line in my irrigation system (the longest one) once works and once it doesn't. I have no idea what is goning on.... it looks like sometimes theres not enough pressure, but why sometimes?
And whats interesting when I open this line, other lines looks like they are leaking (i mean other sprinklers looks like they were sweat). Valves are ok, cause even changing them didn,t work.... pomp has enough pressure (probbably, because sometimes it works)... i heard it might be rock into a hoes, but i run irrigation system without sprinklers and it didnt solve my problem. please help!

By the way, it took two men from 10:30am to 5:00pm to complete the job. They did take time to go pick up parts (about an hour). They also adjusted all of my sprinkler heads. Now that I have so much pressure, they needed to be turned down. But, I still thought it seemed an excessive amount of time. I guess they wanted to give me my money's worth in labor. One man was on his cell phone quite a lot. The other man had only worked for the company for the last two weeks. He did most of the work with supervision. (Thankfully, he was a licensed plumber who has his own company... just not enough business, so he's moonlighting as a sprinkler repairman.) Thought you'd be interested in how long it took these guys.....

The PRV was in an impossible position to get to, so they spread things out when they replaced everything. They also put the PRV in it's own box w/gravel underneath. Hopefullly, it won't be exposed to the dirt/water and will not get corroded so easily. I really appreciate all of the feedback I've been getting from everyone here on the SprinklerTalk forum. Thanks for your prompt and helpful insights.

Replacing the backflow preventer may have made sense if it buys you years of protection the current one may not have been able to provide. And it can make sense, timewise, to replace more than just the PRV, if it is shoehorned into an impossible location.

Well... sounds to me like you got jewed on the pricing.

I understand they need to cover their ass.. But the problem was your PRV.. Not the Back flow assembly, not the valve.. meter.. They were looking to upsell you

If it was me.. I would recommend those upgrades . Replace the PRV and give you a estimate for the rest of the upgrades..

A 3/4" PRV is like around $80-100.. I could have replaced it in probably 2-4 man hours depending on the situation..

But at least it sounds like they did a good job.

The pros showed up this morning and were able to diagnosis and repair my problem today. There was a pressure reducer, but it was buried (not in a box) between the backflow assembly and the meter. There was so little room between those two boxes, I guess the original installers decided they couldn't fit a box in the space. They buried the pressure reducer and it was completely corroded. When the repairman touched it, it fell apart. I must have been losing pressure for a long time. It finally gave out completely last Wed. (letting only a trickle of water through). They also believed that the backflow assembly was not working right (old and somewhat corroded - probably not letting all of the water through). Replacing the backflow assembly and pressure regulartor meant also having to replace the meter and the master solenoid. I really didn't understand why, but they said they could not guarantee the work without a complete replacement of the system. Also, all parts were screwed together and could not be undone one at a time. they had to cut the PVC at a point beyond the master solenoid and then unscrew the backflow valve assembly from the main water shut-off.

Anyway, it's all done and all stations work. They adjusted all sprayers (the pressure is amazing!) The job was a bit pricey ($1,452), but I was in a time crunch and the only other service I talked to could not come out until sometime in June. I hope I didn't get taken... they said the parts were pretty expensive. I wish they could have reused the meter and master solenoid.

Well, that's the solution to my low pressure problem.

Well It's not the sprinkler heads.. It's the valves

If you have 6 zones.. You have 6 valves

It goes Back Flow Assembly >> Main line pipe ( Constantly charged)- branching out throughout your yard>> Valve >> Branching out to a particular zone and sprinkler heads.

Someone could have stopped the flow by turning down the flow controls on the valves.. it's possible but unlikely.

Check your controller, open up the panel and look at the wiring.. There will be a port labeled MV/ Pump. Or just MV ( Master valve) .. Is there a wire leading to this port?

IF there is - turn on a dummy zone ( Ie if you only have 6 zones, turn on zone 7- this will turn on the master valve) Then check out your water meter usage.

By you saying you have bubbling at the sprinkler heads- it does sound to me you have a stuck valve .. which can very well rob your other zone pressures.

Oh... I did try turning up the flow at some of the sprinkler heads without any luck. They do not seem to have been touched by an evil yard elves.

Wow... lots to do.



I made sure there was no water running in the house, looked at the valves on the backflow assembly (both fully on), then checked the meter at the street. Perfectly still. No movement of the little triangle or dial.



Pipe break: This is scarry... but again, the pressure in the house seems to be the same as before. I took a shower with no difference that I could note. I've done dishes by hand with lots of pressure from the faucet and sprayer. Toilets flush and refill just fine... I don't know where to look for "master valve" and I sure hope if I have one, it's not broken.



I examined the backflow assembly again. On one side there is only a pipe coming up from the ground to the assembly (presumably this is from the main water supply). On the other side, the assembly is connected directly to a pipe which exits the box and goes into the round box with the meter. The pipe then exits the meter and goes out the other side of the round box into another box that has lots of wires and a solenoid (at least that's what I think that thing is.)



Someone running around my house turning down all of my sprinkler heads (there are at least 40 of them) is unlikely, but I do have cameras outside. I'll check the recording (if it hasn't re-written over last Tues. night) for any mischief.



The valves at the backflow assembly only make a quarter turn. There is a stop at the full on position and the turn valves are both resting on the stop point. I believe that they are completely on. Also, I did open the valve coming to the backflow when I had the housing open to see if water flowed freely. It did, and quite forcefully. What happens as it leaves the backflow is a mystery. Maybe the exit is somehow stuck closed??? Some water does get through because my sprinkler heads do bubble. They just do not raise and spray anymore.



Bad karma, I think. I'm going to break down and call the irrigation people. I have to get this fixed before I go on vacation later next week. Otherwise, all of my flowers and plants will wilt and die in this awful heat (Alabama in the summer... got to love it.)



Thank you so much for all of your thoughts and helpful ideas. It's been great having someone to talk to about this. I've learned a lot. (Mostly that I need a professional.) I'll post again after someone figures this out.

With your back flow preventor in the on position, and no water running in the house. Check your water meter, there is a leak detector and also a guage.. Is the meter just spinning away??

Ideas come to mind

*Pipe break that is not surfacing- since you claim to have full pressure inside your house either you have a master valve with a pipe break or there is a pipe break w/o a MV and there is enough supply still to supply your house adequately

*Pressure Reducing Valve has gone bad, Typically a PRV is installed right before or right after the back flow assembly ( It looks like a small cone)

*Someone has ran around your yard and turned down the flow controls on all the valves

*Valves aren't fully on