NHRATA01

iTrader: (10)

Hey I know we've got a few good HVAC guys in this section, so I was wondering if someone could give me some guidance.

My boiler is a combo hot water/baseboard heat system (only have a ~1900 ft^2 townhouse), and sits in my garage. Today I walked out and found a puddle there, seems to be a dump tube that has a slow and steady drip, and was leaking the water onto the ground. From what I can gather (of limited HVAC knowledge) this dump tube comes off some kind of T-fitting, that is between the cold water inlet for the system, and the auto fill valve (which itself is just before the expansion tank).

Here's a pic of the fitting with the T:

On the right is the blue valve for the cold water, and at the top left barely in the picture would be the auto fill valve. The expansion tank is the blurry object obscuring things on the left. The pipe T'd off and coming down is what's dripping. So what the heck purpose is that fitting for? And is it leaking because its shitting the bed, or is it doing what its supposed to do and there's a problem elsewhere in the system? Looks easy enough to change out, but I have no clue what it is for replacing it.

My temporary fix was to put a hose around the pipe and run it out the garage emptying into the driveway.

Thanks guys!

Durien

i have no clue but i swear i saw this issue on the home improvements channel or something.. they did replace it with something else...

Nautilus

iTrader: (15)

Could you take a picture from a little farther away? If I understood you correctly.... the leak is coming from a fitting on the cold water feed before your fast fill? When you say dump tube I was thinking a saftey... but you wouldn't have one on the feed side of the fill? If you could take a picture a little farther away it would be easier to understand

obsolete346

iTrader: (7)

That was for air in the system. PBS ask this old house. Damn, I need to find a hobby.

theblur98ss

iTrader: (71)

I can't tell much from the pic but I'm guessing it's a relief valve. Does it have a little lever on it that could be pryed on? Any idea how old it is? Sometimes the gaskets in them just dry out over time from all the heat. May just need replaced.

NHRATA01

iTrader: (10)

Hey thanks for the responses guys.

Tim, here's a couple pics I just snapped zoomed out a bit further



I think you got what I was saying, the fitting is on the cold water inlet, just before the fast fill/auto fill (whatever that valve there is called). I thought maybe it was some kind of check valve or relief valve. The suspect fitting then has a pipe Teed off it that just dumps out to the ground, then the straight through line feeds in to what appears to be the hot water outlet to each of the 3 zones, between the expansion tank and the large grey fitting it Tees off from above the tank. I would've figured the cold water fill would've been piped in prior to passing though the boiler, but what do I know.

Also can I just shut the cold water inlet valve right now, and will that kill the leak? The heat obviously isn't being used right now, however will it affect the domestic hot water supply? (I don't think so but want to be sure).

Thanks again guys!

WJ SOM SS

iTrader: (11)

That is a Watts 9D backflow preventer that is dripping. Either replace the backflow-feeder combo, or just replace the backflow, or lastly, just remove the 1/2" extension tube and plug the backflow device w/a 1/2" brass plug. When these devices get a few yrs. old, they start to leak....You aren't supposed to plug them, but it won't do any harm....It is NOT a safety relief valve as others have said. In Ma., you have to install these backflow devices on hot water boiler feeds to conform to the state plumbing code. Hope this helps you out. WJ BTW, the cold water feed valve-backflow preventer is usually piped in down lower--directly into the boiler and ahead of the heating system piping. (a good piping practice.) Lots of heating people that aren't licensed plumbers don't know that....

NHRATA01

iTrader: (10)

WJ, thanks a bunch for the advice, that helps alot! I'll probably just plug it for the short term and swap in a new backflow preventer when I get a chance.

WJ SOM SS

iTrader: (11)

UR entirely welcome.....1/2" brass pipe plugs are cheap. Enjoy the summer and worry about the backflow in the fall. BTW, just cause it's dripping from that vent, doesn't mean it's not working....Best wishes. WJ