Radiator in two pipe steam system won't drain

Jamie Hall

ice in a trap or return it takes to block a radiator! Had it happen to me once (not this time around!) on a really cold windy day -- with the radiator on yet. Grr... a short whack with a hair dryer and it was just fine.

David Gordon

Radiator in two pipe steam system won't drain

This morning, I noticed that the radiator in one of my kids' rooms was cold. I first disconnected the supply valve from the radiator, and within a minute, steam was rushing up (there seemed to be a bit of a vacuum in the radiator itself when I disconnected it).

I then took the cover off the steam trap bowl and noticed that it was full of water. I took the steam trap out, and the water still just sat there.

Any thoughts on what I could do to get it to drain again? Thanks in advance for the help.

Fred Harwood_2

Water

Frozen dry return? Does the return run in an outside wall? What's the outside temp?

Fred Harwood_2

Frozen dry return

I would try to estimate where the return descends in the wall, and plug in an electric heater to warm that wall. Perhaps by afternoon it will have done the job. You'll know as soon as the water in the trap goes.

Also, was the heat off in that room where the return drops in the outside wall? If so, you might want to keep some heat in that room during cold spells.

Fred Harwood_2

Frozen dry return

So, what happened?

David Gordon

Hi Fred,

I don't think it’s a frozen pipe problem anymore. Warmed up the wall, and also tried putting boiling water multiple times down the return (just kept sucking it out w/ a shop vac after letting the heat dissipate. I may try to couple a piece of larger diameter pipe to the stem leading up to the steam trap so I can put a drain opener in there and try to blow some pressurized water down the line. Tried snaking the line but I couldn't get it to make the turns in such a small I.D. pipe. Any other thougths would be appreciated.

Fred Harwood_2

Air compressor

Take a small air compressor and hold it tightly into the return at the trap. Give it several tries. Might dislodge whatever, and whatever is undefined.

Also, find the downer on that rad in the basement. Might be a drip dirt pocket you can easily take apart and clean. Been there, done that, lots.