Gas Furnace Or Boiler Steam Valve Leak
Home-Wizard™ calculates your ideal home care program to avoid problems with your Gas Furnace or Boiler, but sometimes trouble can still occur. Here are answers to questions about gas furnace or boiler steam valve leak.
QUESTION FROM Todd
Hi there. I have a steam boiler system. I recently turned on the boiler for the first time this year, and a day or so later, my wife noticed water coming from under the bed. When I investigated, I found that water was coming from the radiator nut to shut-off valve threaded connection. It never did this in the past. I thought it might be water in the system or something, but after removing the radiator, opening the valve, (no water, only steam), applying thread paste and re-installaing the radiator, water still gushed out of the connection. Could this be caused by a stuck radiator air vent?
ANSWER FROM HOME-WIZARD
I suspect that the problem is that you used thread paste instead of PTFE teflon tape on the threads. The heating up and cooling down of your radiator and piping can put a lot of stress on the connection causing it to open slightly and leak, but the flexible PTFE tape will keep the threads sealed tight.
If you haven't tried it already, wrap the PTFE tape generously and tightly around the threads. If you can get around 10 winds, this would be good. And other hint, be sure that you are wrapping the tape in the correct direction (along with the direction that the threads will be winding in, so that it tightens rather than unravels the tape).
Hope this is helpful.
FOLLOW-UP FROM Todd
Thanks for the response. I applied 10 winds of tape as you suggested, and it stemmed the flow, but did not completely stop the leak.
My main concern really is finding out what would cause WATER to come from a STEAM radiator valve. The water only leaks out once the connection between radiator and shutoff valve is made. When the radiator is off and the valve opened, only steam comes out. Any other suggestions?
ANSWER FROM HOME-WIZARD
Do you have a single pipe steam radiator system, or a dual-pipe steam radiator system?
In a single pipe radiator system, steam comes in through a single pipe and valve at the bottom of the radiator, and there is an air vent near the top of the radiator. As the steam warms up the radiator, water condenses out and flows back down the same pipe as what is bringing the steam in.
So if you have a single pipe system, this would explain why you have water coming out of the steam valve.
Does this help?