Cold Radiator

Dave_23

Please help. I have one radiator in my home that won't heat consistently.

Details:

House: 2100 sq ft 3 br 2 1/2 bath, 14 radiators.
System: Two pipe steam
Boiler: Weil McClain 150,000 BTU
Cold radiator location: 2nd floor bedroom, NOT farthest from boiler.

Symptoms:

1. Veritical inlet/riser pipe at radiator heats up to shutoff valve (too hot to touch). However, radiator won't heat.
2. Shutoff valve fully open
3. Radiator in question heats fine on first heating cycle of season, then no longer heats on subsequent cycles.
4. Other radiators in house work fine.
5. No water hammer.
6. I TEMPORARILY installed a 1A adjustable vent on the radiator for test purposes. Radiator still won't heat. Inlet pipe gets hot though. Plenty of air rushes from the vent upon boiler firing.



Please help? Any other diagnostic tricks I might use to identify the problem?

Fred Harwood

cold rad

Does the radiator have a trap at the outlet?

Dave_23

Cold rad

No it doesn't. In fact there are about three rads in my system (again, two pipe) that don't have traps. Not sure why. Thanks, I'm a rookie on this subject.

Unknown

Are those three original,

Or are they newer piping? I'm trying to figure out what the system started out as...

Noel

Gary Fereday

brainstorm ?

Rad valve is open, how do you know ? If it were broken just right it could act as a check valve, it would let in steam, that would condensate to water and then the water could not get back down, Trapped there not allowing in steam cold rad. all summer it leaks down and then a one time fill of steam fills up with water and no heat. bigugh

Steamhead

It's probably Vapor

Check your e-mail, Dave- I didn't realize this was on the Wall too!

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Fred Harwood

cold rad

Trace the outlet pipe and tell us where it goes.

Dave_23

Cold Rad

If I had to guess, it looks like someone removed the traps and replaced them with short nipples and unions. All rads except the one that won't heat appear to be original (they all work very well, except for the one that won't heat)

I've confirmed that the valve on the rad in question is not broken, opens all the way and doesn't leak.

DanHolohan

Could be an orifice system

Might be running on too high a pressure.

Dave_23

Could be an orifice system

Normally, would a system consist of orifice equipped rads and trap equipped rads. Or is it one or the other exclusively?