# New homeowner sprinkler system question



## photog1985 (Aug 25, 2020)

Hi Everyone.
I'm a first time homeowner and new to the sprinkler system experience. I have done extensive research on sprinkler system startup/shutdown and know the basics. The issue I have is that all tutorials have all the common components such as the shutoff valve, backflow preventer, and the programmer. I have everything but the backflow preventer it seems. I have located the shutoff valve, the programmer, as well as all the sprinkler heads in the yard. I just can not find what looks to be a backflow preventer which all tutorials show. I am attaching pictures of several pipes and valves I have located to see if anyone can help maybe point me in the right direction. I understand this is a basic question but I don't want to attempt anything with the system without knowing how my system is set up first. Thanks in advance for any help.





Shutoff Valve:


Main Water Shutoff Valve:


Gas meter


This says backflow preventer but I don't know if it is for sprinkler since it is in basement. I thought it has to be above ground:


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## g-man (Jun 15, 2017)

The first image is not your water meter. That's your gas meter. Don't touch it.

The second one has a pvc loose cap on top. Remove it to see what's inside.

The third is 3 valves for zones.

The last one might be a backup preventer, but I don't see the test ports (so it might not be "legal"). The thing behind it looks like a pressure reducing valve.


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## photog1985 (Aug 25, 2020)

Thanks on the gas meter tip. I opened the pvc cap and all it was is a huge pipe going down. I have 2 of those.


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## g-man (Jun 15, 2017)

That might be a sewer vent. Ask someone to flush a toilet while you look/hear.


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## Justmatson (Apr 4, 2020)

@photog1985

The thing that says backflow preventer is a check valve, probably a double check valve. It allows water to only flow one way. 
You have to check with your local codes if they allow it. If your main water supply is municipal (city water) not for drinking, good chance its total legal.
I'm on a community well and they allow a double check valve as a backflow preventer.

It can be installed anywhere, vertical or horizontal, above or below ground.

The valve behind that is your pressure reducer. You probably have high pressure coming from your source. I have the same thing. 
110psi that must be reduced before flowing through the house.

What I do find weird is they placed the check valve before the pressure reducer... where does the line after the pressure reducer go?

Might not even be for your irrigation....


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## photog1985 (Aug 25, 2020)

Justmatson
The Backflow preventer doesn't appear to be for the sprinkler after further inspection. The ball valve. in the picture is after the main water inlet and it has a little screw for draining any leftover water. I just can't figure out if there should be a backflow preventer or not.


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## Justmatson (Apr 4, 2020)

photog1985 said:


> Justmatson
> The Backflow preventer doesn't appear to be for the sprinkler after further inspection. The ball valve. in the picture is after the main water inlet and it has a little screw for draining any leftover water. I just can't figure out if there should be a backflow preventer or not.


Where does your water come from? City or you on a well?

But yes you should have some kind of back flow prevention for an irrigation system.
If there is not then this one was most likely installed without a permit or legally.

Did u figure out what those 4" pvc pipes going into the ground are for?
Likely a septic tank clean out as g man has stated.

I've got a 4" pvc pipe going into the ground but it's near the street. Its actually to protect the water main shutoff valve to the property. Just take a flashlight and have a look down. Some valves can be 3-4' deep.
I do think its a clean out though


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## photog1985 (Aug 25, 2020)

The water comes from city. As for the 4" pipes I still have to look closely with flashlight as you suggested. I also have a crawlspace under the house to inspect and see maybe the backflow is there. Thanks for all suggestions


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## mwemaxxowner (May 30, 2020)

Depending on who installed it it's possible there isn't one!

The existing system on my property was homeowner installed about 30 years ago and there is no backflow preventer of any kind.


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## photog1985 (Aug 25, 2020)

Strange if so but I guess anything is possible. Would it be possible to put one in after the fact or does it all need redone?


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## Justmatson (Apr 4, 2020)

photog1985 said:


> Strange if so but I guess anything is possible. Would it be possible to put one in after the fact or does it all need redone?


Yes you can absolutely add one. Call up your city to find out what they require for code. 
Could also try calling an irrigation company or plumbing company they may know. You might have to get a permit too.

You either need a:
check valve (cheapest/ easiest)
Pressure vacuum breaker (most common, little more expensive and needs to be installed higher then the highest sprinkler head) 
Double check valve back flow device (expensive, most reliable, and be mounted anywhere)

Does the water line that supplies your irrigation tee off your main water line before or after that check valve and pressure reducer?


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## photog1985 (Aug 25, 2020)

The water comes in and splits off to house water before the check valve.


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## photog1985 (Aug 25, 2020)

So after checking the crawl space I mentioned, I found nothing resembling a backflow preventer, as I had expected. Next step is contacting the home inspector to see if he maybe ran across it during inspection. If he comes back with nothing I'll just have to get a company to do a irrigation inpection and see where that leads.


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## SOLARSUPLEX (Aug 4, 2020)

Not as a last resort, but you may be able to contact your realtor to get in touch with the previous owner to ask if they can point you to the valve or the installer that worked on the system in the past. If it's DIY, i would imagine it doesn't exist.


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## Turfler (Jul 1, 2020)

The pressure reducing back flow preventer is for the water feed to your boiler for your heating system. It is only a 1/2" line, and not part of the irrigation system.


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