Plumbing woes
February 17, 2014 8:12 PM   Subscribe

I'm asking this Q for a friend and I really hope someone will be able to help. We moved into our house about two years ago. We've had problems with our sprinklers in the past and when we had them repaired, a sprinkler expert told my wife there was "something wrong" with how we get water to the front since they couldn't shut off the water. That didn't make sense to me, but now that I've tried to fix the sprinklers in the front myself, I've encountered the same problem. When I turn off the shut off valves near the water meter (what I think are the main valves), nothing happens, though it does turn off the water to the backyard. When I need to repair plumbing inside the house, the valve close to the house does the trick, but again, I can't shut off water to the front sprinklers. I have no idea how the sprinklers were installed, but it is getting frustrating and I'd like to know how to go about troubleshooting this. Is there any way to identify where a valve might be to shut off the water to the front sprinklers? Here's a simple diagram I drew. Thank you!!!
posted by BitterYouth to Home & Garden (17 answers total) 2 users marked this as a favorite
What was the nature of the problems you had in the past? Do you have these sprinklers on a timer? If so, the wires from the timer must go to valves that are controlled by solenoids (usually 24 volts AC). So where are these solenoid valves? Do the "shutoff valves" out by the sidewalk have wires attached to them, or are they hand operated valves? And you say "valves" (plural), so there must be more than one. But you would only need one to shut off the back yard sprinklers, so what does the other valve control? Is it on the same line (pipe), or is there a separate line? Can you post a picture of these valves? Maybe the valve controlling the front sprinklers is broken in the "on" position, so turning it does nothing, or perhaps there is another valve on an offshoot line between that box and the city water meter. The only other possibility I can think of is that the front sprinklers are fed by a line that the city missed when it installed the meter. You can dig to follow the route that the pipes take, but they are likely PVC (white plastic) so dig carefully so you don't crack them. Are you located in an area where the pipes would freeze in winter? If so, you would have to blow out the lines with a compressor in the fall, to get rid of the water.
posted by weapons-grade pandemonium at 8:34 PM on February 17, 2014

Response by poster: @weapons-grade pandemonium The sprinklers are on a timer with a control box in the garage. I've followed the wires to the solenoids, and know where they are. The problems have been busted sprinklers, and this year a broken solenoid, which is hard to replace if you can't turn off the water to the solenoid. The valves near the sidewalk are downstream of the city meter, are handoperated and metalic (copper?) They are both inline and as far as I can tell only turn off water to the backyard. My current guess is that the front sprinklers are connected somewhere else, perhaps even upstream of the city water meter, or perhaps even to a neighbor's line (which would be bad, of course).
posted by BitterYouth at 8:40 PM on February 17, 2014

I can't figure out why you would have two valves on the same line. Are you sure there isn't an offshoot line? What geographic area are you in? To avoid future problems, look for (and clean out) a large irrigation filter intended catch sand and silt that would clog your sprinklers. You should also have an anti-siphon valve in the irrigation lines to prevent outside water from siphoning back into your household lines. You could always try another irrigation installer. Any decent firm should be able to diagnose your problem.
posted by weapons-grade pandemonium at 8:45 PM on February 17, 2014

How many solenoid valves do you have? Sometimes there is a master solenoid that shuts off water to the other solenoids. Maybe you should explore the possibility of a neighbor's line feeding your front sprinklers, and check out their shutoffs. An easy diagnosis would be to have them shut off their water at the road to see if that shuts off your front sprinklers. I can't see any irrigation company not installing a manual shutoff for that front line. In any case you should pursue a solution, because if you get a break in the line you will have a flood that you can't stop.
posted by weapons-grade pandemonium at 8:52 PM on February 17, 2014 [1 favorite]

Maybe the water going to the sprinklers is supplied differently from the water going into the house. In some areas, water for outdoor use goes through a separate meter, or no meter at all, because it's billed differently. (Typically there's no charge for sewage, since it doesn't go into the sewer but just into the ground.)

So it could be that the incoming line from the street splits, and part of it goes to your water meter and part of it goes to your irrigation system, perhaps without going through the shutoff valves that you would expect to affect it.

You might need to get the water company involved; they might know where it actually branches off from and how to shut it off in order to work on the system. In my area you can always call them and have them turn off your water supply completely (from the street water meter) if you need to work on the main valve, which is basically what you require. It's just that you need to work on the main valve to the irrigation system, not the house. But they should still be able to figure it out.

I'm not sure how else to go about troubleshooting the system.
posted by Kadin2048 at 9:03 PM on February 17, 2014

Response by poster: I'm in Texas. There may be an offshoot line, but I can't find it or figure out how, short of digging. There are multiple solenoids (at least 4 in the front yard alone), and yet there is no way to shut off the water. I don't think there is a master solenoid. I will take a picture tomorrow as it is dark out right now. I think I need to open the city water meter and shut that off to see what happens.
posted by BitterYouth at 9:04 PM on February 17, 2014

Is it is possible that the irrigation system was installed before the sidewalk was put in, and the valve for the front yard ended up under the concrete? You could dig carefully as close as possible to the edge of the sidewalk to explore that possibility.
posted by weapons-grade pandemonium at 9:09 PM on February 17, 2014

Response by poster: That is a reasonable possibility, that the takeoff for the front of the house is in front of the two valves that control the back. Perhaps in between and under the sidewalk. I guess I need to shut off the water from the city side to see what happens. If that shuts off the water, then there is a takeoff somewhere else. If not, then the takeoff for the front occurs even before the city meter (maybe from the neighbor...)
posted by BitterYouth at 9:14 PM on February 17, 2014

This is kinda worrisome. All irrigation lines need to be behind a backflow preventer to prevent contaminated water from getting into the town water supply. If a previous owner hooked directly into the water main without this preventer you really need to get this fixed. The biggest part of public health is a clean water supply. See if you can find the backflow preventer, it should have a cutoff valve as well for the whole system. If you don't have one of those, you need to get one. If you do have one and that doesn't stop it, you need to get the front system hooked up to one. You may need to hire a landscape company that puts these in to find and operate the system. You can always call the water company (or town) and work through them. If you do STRESS you bought the house this way and just want to make it right.
posted by bartonlong at 10:21 PM on February 17, 2014 [1 favorite]

perhaps even to a neighbor's line

This was my first thought. I'd ask your next door neighbors if you can take a look at their setup. Even if it's not connected to their line, one of them might know the trick to shutting off the front sprinklers (assuming your irrigation was installed similarly).
posted by Rock Steady at 5:30 AM on February 18, 2014 [1 favorite]

I think I need to open the city water meter and shut that off to see what happens.

That's the first step -- that will tell you if the irrigation feed comes after the meter or not.

Beyond that, there isn't honestly much that can be diagnosed over the internet. A good irrigation company (not a dude with a pickup, but a place that does diagnostic work) may need to be involved. You can trace wires underground if you are needing to find additional wired valves, for example. There may be a missing or malfunctioning shutoff valve, or that valve box may just be buried with grass over the top. Just from the description I'd guess a malfunctioning valve, but that's worth nothing as a guess compared to actually testing them.
posted by Dip Flash at 5:55 AM on February 18, 2014

One thought is to look for a shut off valve at the street. Ours was right where the meter was and you needed the Curb Key to shut the water off at the street.

One thought, that seems absurd in TX, is that the irrigation might be a gray water system? No. I thought not.
posted by Ruthless Bunny at 6:21 AM on February 18, 2014

Best answer: I'm in the irrigation business, and I'll try to give you a step-by-step list of how I'd approach this. I'll be repeating some of the good advice you've already gotten.

1 - Turn off the water supply at the meter, then try to run the system to rule out the possibility that the front yard is tied into a different source (or possibly upstream of the meter). I've seen this very rarely in cases where the house had been a model home in a development. If this does cut off the water to the front yard, go to step 2.

2 - Inspect the manual cutoff valves in the box in the front yard. Obvious question, but not clear in your post: Are they inline with each other on the same pipe or are they on two different pipes? Occasionally, I'll see two valves in line where someone has fixed a bad valve without removing it. If the valves are in line and appear to be part of one large bronze fitting, this may be a type of backflow device known as a double check valve assembly. If so, only part of the system is being served by the backflow device. More on backflow devices later.

If the valves are on two separate pipes, go to 3. If they are on one pipe or a double check valve assembly, go to 4.

3 - Try turning only one valve off at a time to see if they shut off the supply to different areas of the back yard, or if only one of them is controlling the flow. If only one of them seems to be controlling flow to the back, the other may be a malfunctioning valve for the front.

Run the sprinklers in the front yard. Try to determine if water is running through either of the valves. Feel for vibration or a temperature drop in the pipes. Listen. Try opening & closing the valves to see if there is any change in flow to the sprinklers or if you get a vibration or sound change. Sometimes a malfunctioning valve will still have the ability to close a little and affect the flow.

If you suspect that one of these valves is responsible for flow to the front, replace it and see if that fixes the problem.

If you go through these steps and are confident that front yard flow is not going through either of these valves, go to step 4.

4 - Try to find other manual cutoff valves. Probe around near the known valves with a large screwdriver, hand shovel, etc. to find another valve box. Also look in the area of the house cutoff valve. If the system was installed in phases, particularly if different people did the work, they may have tapped in there when they did the front portion. Another possible place would be just upstream of the solenoid valves serving the front yard. Still another place to look would be in the crawlspace or basement, if either is present.

Cutoffs are usually placed as close as possible to the point at which the main water source is tapped, but not always. Ideally, there is only one point of attachment with one main cutoff valve for the whole system. If you can't find the cutoff for the front yard, one can be installed right behind the front yard solenoid valves, as long as you can find them and they are grouped together. Otherwise, valve-related repairs will require cutting water off at the meter, and this is far from ideal for a bunch of reasons.

As others have mentioned, some sort of backflow prevention device should be present in any sprinkler system attached to city water. In most municipalities, they require a device that can be tested and inspected, such as a PVB or RPZ. The PVB is most common in my part of the country, and it's hard to miss because it has to be installed above ground to work properly. Some more lax areas only require a double-check-valve device. These can be buried and many are not testable devices.

Because of the situation described here, my guess is that this system may wholly or partly be a homeowner or handyman installation, and that at least some of it isn't up to code. If a backflow device is required by code in your area, it could be a bit of an expensive headache to get one installed upstream of all the different lines involved here. If the two valves you have found are indeed part of a double check valve assembly, the trick will be getting the front yard tied into it correctly.
posted by gimli at 10:10 AM on February 18, 2014 [2 favorites]

Response by poster: @gimli - Indeed it does appear to be a double check valve. I will follow your advice to see what happens. Thank you!!
posted by BitterYouth at 6:29 PM on February 18, 2014

Response by poster: @gimli - I do have one follow up Q. How do I know if the double check valve is functioning correctly? Which valve do you turn off first, what does that do, etc.?
posted by BitterYouth at 6:36 PM on February 18, 2014

A double check is a pretty simple device that just ensures that flow can only go in one direction. Since we have flow to the back yard, we can assume it's installed correctly. No way to be sure it'll do it's job in the event of a backflow situation, which is why they aren't favored in a lot of places.

It's not critical in this situation, but I usually recommend closing any backflow device downstream side first and opening it upstream side first. Upstream is water meter side in this case.

As things stand, it looks like the search is now on for a separate valve serving the front. With luck, it will turn out to be another double check assembly so there won't be backflow concerns.
posted by gimli at 7:12 PM on February 18, 2014 [1 favorite]

Forgot to add, if the house has a basement or crawl, that would be the first place I'd look. If it's on a slab, then the search can be tedioua, and we just hope it's in a logical place.
posted by gimli at 7:22 PM on February 18, 2014 [1 favorite]

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