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Leaky Radiator Valve


I just moved into a home (built in the 1940's) with steam heat radiators. The radiators themselves haven't been maintained for a while so I've spent some time tuning them up (I flushed the system, put graphite packing where needed and replace all steam blowoff valves). Everything seems good to go except for one of the radiators. No matter what I do, I have steam coming out of the hole that the blowoff valve actually screws into. I've cleaned the threads of the hole, wrapped the valve itself with lots of teflon tape several times, and it's still leaking. Anyone have any ideas?



Re: Leaky Radiator Valve

There are a number of thread sealants that the heating/plumbing supply houses carry (Yellow Pages: "Heating-Parts").

Check the radiator at the threaded hole closely to see if there is a hairline crack in the cast iron itself.

Ask the counterman for a recommendation, or try:

1) Rectorseal #5 8 oz. can.
2) Gasoila Pipe Joint Compound 4 oz. can.
3) Liqui-Vac high vacuum sealant 4 oz can.
4) Laco Slic-Tite thread paste 4 oz can.

Re: Leaky Radiator Valve

I looked more closely at the radiator and there is a small crack above and below where the steam blowoff valve screws into. I went out and got some J-B Weld and applied that to it. It seems to be working. I think I missed a small spot. I'll have to apply some more and see if that does the trick. Thanks for the advice though!


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