I posted previously but didn't "know the product."
What I have is an irrigation that continually seeps or drains. I have replaced the zone valve and it still leaks. I'm at my wit's end, the entire mess started when I had a well drilled for the system and the irrigation guy said I didn't need a filter when he hooked up the well to the system. I subsequently put a filter on the supply line and there is a lot of sediment in the filter when it is drained.

Why is the low lying sprinkler draining or weeping? I replaced the zone valve and even left it not connected to the power source and still it drained. Everything I've read on the internet says it's a valve if a sprinkler persistently and continually drains. Could I need an anti-siphon valve? I know the valve I replaced controls the low lying sprinkler because I manually turned it on.

I'm at the point where I'm about to manually water from the control box every other day and shut off the water supply when I finish watering until the next time....

 

Water is always going to drain out of a irrigation system after it is turned off. Especially at the lowest sprinkler as water flows down hill. It is exactly the same when you turn off a hose with the hose end open. Water will continually drain out until the water is gone. This is even helped with a anti-siphion valve.

 

I know that the low-end sprinkler will continue to drain even with the valve off. My problem is that all the water in the well tank empties in about 4 hours and I have found no leaks in the system except for the low-head drainage that is persistent. With the valve off there is no need (in my estimation) for a anti-siphon valve because there isn't water supposed to enter the lines. I ned to tell you though, two sprinkler repair guys came and told me the exact same thing-"It's supposed to drain, it's the lowest sprinkler." But with the valve off NO water should be draining after the initial drain when water is shut off.

 

Since you have replaced the zone valve and the system is still draining through the valve my first suggestion is a check valve after the zone valve. If that still doesn't handle the problem a manual shut off at the tank would be next.

 

Mike, I do have manual shut off at the tank and have been using it occasionally when working on the system. If I put a check valve after the zone valve, it will prevent water from backing up but still will allow water to run to the valve? Is that the check valve you mean? It is brass and costs around $13.00? I thought I fixed the problem when I put a new gear driven sprinkler head in yesterday, I went into the garage and lo, the tank was full. Then I found I didn't shut the breaker off during the night...

 

There are many types of check valves. the best one to look for to deal with your problem is one that requires at least 10 to 15psi to open. this will require the zone valve to be fully open for water to flow through the check valve while stopping the trickle you seem to have when the valve is closed. I've used check valves in this way many times and usualy had good results.

 

Thanks Mike! I'm going to be on the lookout for the check valve. I'll start by an internet search.

 

I have been looking on the internet and cannot find a 10-15 psi 1" check valve, do you think a plumbing supply might have it? That's the only place I can think of that might have one. Or adjustable?

 

A plumbing or irrigation supply house should have the check valves but possibly with a max setting of 5psi which should still do the job for you.

 

Well, I located a valve, installed it and the tanks till drains. I am getting desperate and have about decided to put a plastic ball valve after each zone valve (one at a time) until I locate the source of the seepage. Mike, have you ever done something like this? I know it's a bit of work but if I want to find the leak I know of no other way. I could put a cut-off before each zone box (two boxes) and at least I'd isolate which area I'd need to dig.... I'm going to persevere and keep you posted as to the results but am going out of town for 2 weeks Monday.

 

Your best bet IMO is to install a master valve. This is common an irrigation systems I have seen here on the east cost.

Irrigation Master Valves

A check valve is only good for low head drainage. Which you might have and really have two issues that you dont know you have.

So one is the low head leak that will eventually stop.

You may have a leak from the vacuum breaker to the zone valves. That may be causing your pump issue.

A master valve will be a good choice until you can actually find the leak.

Additional info here.

Irrigation Helps & Tutorials - Wet Spots or Slow Leakage out of Sprinkler when system is Off

Mike NJ

 

Gotcha on that one, I don't have a master valve. I did have one until I had the well drilled and disconnected the water supply from the house to the to the irrigation system via the well. The supply line goes from the well tank to the zone control valves. My opinion is that when the irrigation guy hooked up the lines I asked him if I needed a filter and he said no. I put a filter in and you wouldn't believe the sand and grit I get out of the filter. I believe the sand/grit has something to do with the seepage. There was silt in one of the valves I took apart.

 

lawrosa is right about having a master valve between the filter and the zone valves. Isolation valves at each valve box can't hurt because it makes replacing valves easier although with a master valve they are not realy necassary. the seepage issue could also be something as simple as a valve bleed screw being slightly open.

 

Guys, I finally found the leak and fixed it! We were gone for almost two weeks and I forgot and left the circuit breaker on that powers the well pump and when I mowed after our return, I found that the ground was pretty soggy in one area and figured heck, that's it so I changed out the diaphragm in the control valve that feeds that particular area and the pressure tank is holding pressure all evening. Thanks for your help and advice! Job well done!