Radiator Clanging Driving Me Crazy

sreja

We recently replace the thermostatic traps (and replaced all valves with TRVs) in our two-pipe steam heated building (about 85 radiators).

In my unit of 5 radiators, one of them which always worked fine before, is now exhibiting a very loud single clang on a regular basis every couple of minutes.

It never made this sound before, and it heats fine now and did so before all of the work.

Note this is definite not a start-of-cycle problem; it seems to happen throughout, but i will keep studying it to see if i can understand more any pattern -- by memory i think it happens more while the radiator is cooling than when it is already superhot.

This sound is driving me crazy.

Any suggestions as to what it might be and how i would diagnose and fix? Could it be a failure of the new trap on the radiator?

Help!

sreja

thermostatic trap replacement capsule kit swapping?

A related question:

We had all the radiator traps replaced -- one major motivation was so that we could easily get rebuild kits for the traps.

My question is -- is there any harm or danger in opening up a trap and trying out a replacement capsule kit to see if it solves a problem, and then replacing the original innards if not?

In other words -- can i use a replacement trap capsule kit as a testing device?

Or is it a case where if you open up the trap and use the kit, you cant reuse it if it turns out the trap was fine in the first place.

[before you ask, these are Sarco TA-125 model traps]