Two Pipe Steam: New Radiator and Valves - Bad Valve, Trap or Something Else?

KarlW

I have 2-year old radiator (Castrads) in its 3rd heating season (December 2020) that has stopped heating.

In my limited diagnosis I have discovered the following:

• The inlet steam pipe gets hot.
  
• The condensate pipe below the trap gets hot (this may be key after reading other posts)
  
• The valve gets hot on top
  
• The radiator itself does not get hot, although the leftmost fin gets hot, likely from metal to metal heat radiation.
  

Everything in the picture with the exception of the inlet stem was installed new in Dec 2020. The radiator has some slope, although I've also had it with no slope as recommended by Castrads (it looked like may have had uneven pitch).

This radiator is among four-five at the furthest point of my house loop, but the nearby radiators get hot and as I mentioned the inlet and outlet pipes get hot as well.

It does look like my summer will be spent replacing steam traps. I have one leaking for sure, and others that I have reason to think have gone bad.

Is this enough information to provide a few possible diagnosis? I know one of them could be a bad thermostatic valve, but it is so new that I doubt it.

I also hope that a radiator expert in Western NY finally appears so I can give them my money.

Thanks in advance.

clammy

From your writing it previously work . I would think if your outlet of the trap is warm and the radiator is cold then you possibly have a bad trap bypassing steam into the dry return . Usually when this happen it’s the end of any steam circulation . Does your system contain crossover traps at the end of the steam mains which would connect to the dry return ,when they fail it will pressurize the return also. You should start your system when cold and follow out the piping as it heats ,also start check radiators and dry return piping . One bad egg soils the dozen same applies for traps .
Peace and good luck clammy

KarlW

Thanks! A failed trap allowing steam to enter the condensate line would totally jive with some other symptoms:

• Nearest radiator (that does heat) spits water out of the trap even when valved off.
  
• Incredible pipe banging - enough to turn on a motion sensor light.
  
• Clicking/grinding noises in the pipe during operation (separate from the banging).
  

I don't believe I have a crossover - if I do it is at the boiler itself. Otherwise it is a truly two pipe system with separate supply and return.

Tracing it is a problem as it is on the second floor and I have a partially finished basement that doesn't allow me to see all of the pipes to help determine where the exact problem is - perhaps my best bet is to start dismantling my traps one by one.

Oh, and it did work when installed - I wouldn't have let them leave otherwise...

clammy

Being you have a some what finished basement ,just follow out your system which rads are first and back track and feel the radiator outlets it won’t be to hard to find it will the one that’s cooking . Hopefully 1 bad trap is not destroying the elements of your other traps that’s what usually happens . Running a system using a vaporstat and possibly sizing the supply valves w orifices would eliminate the need for traps and or lessen the amount of steam entering the radiator hence condensing before leaving the radiator .
Peace and good luck clammy

clammy

From the looks of it usually most rad valves are installed w the union spud installed in the radiator and the valve is threaded onto the supply . I would make sure that the orientation is correct as for inlet and out let being I’m not familiar nor have seen that valve body . It that a valve body for a trv head . Peace and good luck clammy

Jamie Hall

The crossover TRAP would be at the end of the steam main in place of a main vent, and connect to the dry return at that location.