Radiator isn't getting hot

mcp1

I have a room on the 2nd floor of my 3 story 1600 sq ft colony style house (in the Northeast) that's not getting an steam heat to the radiator. I have a single loop steam system. The pipes are not well insulated (spotty at best). The run going to the riser that supplies the room feels hot when it comes off the main, but is cold to the touch about 3' down from that before the riser. I'm going to insulate all the pipes, will doing that get the heat to the room that doesn't have any? Also, off the same run that supplies the riser their is a Tee that branches off and supplies a bathroom on my 1st floor. Could that branch off steal the heat from my 2nd floor?

ethicalpaul

The insulation is nice, but the lack of it would not prevent steam from getting to a radiator, so rule that out.

I'm having trouble fully picturing what you are describing, but from what I can discern, I will say it is possible for a line that supplies multiple radiators to have difficulty supplying them all depending on the size of the pipes and the radiators, I don't suspect your bathroom radiator could steal all the steam from your other radiator.

It sounds to me like the vent on the cold radiator is failed closed, or you have a "valley" in its supply line that is filled with water and is killing or blocking steam from getting to it.

One easy thing you can do to get some more info is to remove the vent on your cold radiator, then turn up your thermostat to force a call for heat, then monitor the supply pipe temp and the radiator to see if steam then can get to the cold radiator.

Listen carefully near the cold radiator, and see if you hear gurgling. Report back! And welcome

PS: you said "single loop" but you might have meant "single pipe"

mcp1

Thanks for the info. What do you mean by "valley" in the supply line? Are you saying it might not be pitched correctly and collecting water in a certain point of the pipe?

ethicalpaul

Exactly. In most/all 2nd floor radiators, there is a short horizontal section between the floor joists just under the radiator. This allows for expansion of the vertical riser without lifting the radiator off the ground, and eased initial installation when the home was built.

Due to house settling, it is possible for that short section to form a water trap that can limit steam flow to the radiator, and cause gurgling and/or water hammer.

mcp1

That would make sense, it feels like i live in a fun house at times; my house settled tremendously.