Sprinkler Line Missing Shutoff Valve

[Derek C]

Hey everyone!

My situation is this: my wife and I recently bought a house in Denver, CO. The first snow of the year is coming up, with temperatures expected to reach a low of 16. In preparation for this, I borrowed an air compressor from my dad and we flushed the sprinkler lines. However, we were unable to find the shutoff valve for the sprinkler line anywhere. It looks like the pipe goes straight into where the basement ceiling is, but the ceiling and walls down there are drywall, and I can't imagine they'd put a valve behind drywall.

The seller of the house is a builder, and I'm guessing that he either did it himself or had one of his subcontractors do it, and I believe that the sprinklers were done since last winter. I have a sinking suspicion that somehow they did not install a shutoff valve. I've reached out to the seller to find out if it's in some strange place, but haven't heard back.

The snow is expected this Thursday, just a few days away, and I imagine local plumbers are swamped with everyone looking to do the same preparations, although I plan to try to schedule something tomorrow.

So, my question is this: If I'm unable to locate the shutoff valve and unable to get a plumber to do an emergency installation of one, is there anything I can do to protect the exterior pipe? My thoughts have spiraled into keeping a space heater running out there with a blanket over it, or changing out some hot stones every 30 minutes, or (best idea) starting a small fire next to the pipe with a tipi around it. I'm sure there's some pipe installation I can get, but would that be enough? I suppose worst come to worst I could shut off the water to the house and drain it for the day.

Any advice would be appreciated, thank you!

Derek

 

[Terry]

An irrigation system should have either a vacuum breaker or a reduced pressure double check valve. Most of the time, the double check is outside the home, below ground and that's where I would expect to see a shutoff. A shutoff inside would be very nice though.

How did you flush the lines if you couldn't shut water off to it?

 

[Sponsor]

 

[Derek C]

I've attached a picture of the setup. The white PVC leads to a couple manifolds for the sprinklers. I flushed the lines by stopping the right-most valve.

I may be totally wrong here, but don't I need to drain the copper pipe preceding that first valve? I thought that pipe would lead to a shutoff valve inside the house that could be drained

 

[Sylvan]

The copper riser had better be drained . I wonder why the installer did not place a union on the vertical PVC so the line can be separated and tythern the compressor can be used to blow the line

There has to be another shut off valve prior to the one outside otherwise it would have frozen last year

Have someone tap on the copper gently as someone inside can hopefully trace where the sound is and locate the other shut so it can be drained

If you cannot locate a shut off you better think about heat tape and insulation

 

[Derek C]

From what I can gather, the whole irrigation system was put in this year, since the previous winter, as the previous owner was remodeling getting ready to sell. I ended up getting the heat tape and insulation for this snow at least, but I will definitely try tapping the pipe. Thanks for the tip!

 

[Derek C]

I went and got the heat cord and insulation. I’ll attach some pictures of the cord placement and insulation placement (sorry for poor lighting). I would appreciate some feedback since this is the first time I’ve done this!

 

[Sylvan]

I would make sure the extension is plugged into a GFI outlet possibly seal the openings a little better with more insulation larger size facing 180 deg from this one so the seams are not allowing water to enter and leave the bottom a little open for drainage just in case