Did the cold weather break my backflow or my water feeder valve?

foresthillsjd

Preface: I know I have two other open discussions, just waiting on parts and borrowed tools to try everyone’s suggestions.

today it was 20 degrees today, and I noticed that the thermostat had an error. When I checked the boiler, there was a low water level and the auto feed was just buzzing.  I tried just opening the supply valve, nothing, so I turned the power off to the boiler and checked the supply pipe.  It has the unfortunate fate of running right by the window I keep open for fresh air, and it froze a little.  

I hit the pipe with the hair dryer, and water started gushing out of what I think is the pressure relief pipe.  I opened the manual water feeder valve so some water would fill the boiler, and then I shut the water supply off further upstream.  

In the meantime, I’m putting heat trace and insulation on the piping nearest the window and eventually getting a fan in a can.  

Should I call a professional in to diagnose and repair?  (Would still love recommendations for anyone serving Queens… direct message me if you don’t want to post here.)

jhewings

That's your back flow preventer valve which is above you water feeder I think. When you added water, did water go in the boiler? Do you have heat now?

Jamie Hall

Water should not have come out of that backflow preventer. If you open the valve leading to it and the automatic feeder, and operate the automatic feeder manually (most can be), does it work? No water out of the backflow preventer? If not, of it there is water gushing out again, the backflow preventer may have been damaged by freezing as well.

If so, you will need to keep track of your boiler water level manually for the time being -- no harm to that.

foresthillsjd

jhewings said:

That's your back flow preventer valve which is above you water feeder I think. When you added water, did water go in the boiler? Do you have heat now?

Yes, when I added water via the ball valve, the water coming out of the other pipe slowed down but didn’t stop.  So we have heat and I’ll resume my investigation tomorrow.  

foresthillsjd

@Jamie Hall that’s an interesting suggestion/ experiment. When I tried operating the auto feeder manually, it had no effect on the flow rate of water pouring out the backflow pipe. 

foresthillsjd

Update, took out the auto feeder and the backflow, and both were toast.  Could it be that once one failed, it broke the other?  I had a friend come and show me how to sweat pipes.  Everything is working now.  

mattmia2

Could there be ice stuck in the backflow preventer keeping it from sealing? A frozen pipe produces a lot of pressure from the ice expanding that could have broken something.

Jamie Hall

It is much more likely that both froze internally. Both are surprisingly delicate mechanisms, and only a very small amount of ice in the wrong place and they're gone.