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TRV bang

kcopp
kcopp Member Posts: 4,472
What would cause a TRV to bang when the heat is running?
TRV has been in the system for close to 15 yrs... no issues. The system is able to be quiet if the valve is opened up 100%

Comments

  • If no changes have been made to the system, replace the TRV.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • GW
    GW Member Posts: 4,831
    Take the TRV head off, and push against the piston-valve with a blunt object. If you can re-create a noise, your flow is probably going backwards.

    If there’s no odd noises, I would take the TRV head off and swap it with another radiator somewhere else, see if the noise follows or see if the noise stays
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
    EdTheHeaterMan
  • kcopp
    kcopp Member Posts: 4,472
    The entire TRV or just the head?
  • GW
    GW Member Posts: 4,831
    You should be able to take the head off pretty easily, it’s usually finger tight or channel locks will loosen it. If you’re really unlucky, you won’t be able to separate the head from the valve. I hate when that happens. So, take the head off, and push against the little piston and see if you can replicate the noise
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • kcopp
    kcopp Member Posts: 4,472
    Thanks.
    From the description I was wondering if you were suggesting to drain down the system and pull out the entire assembly.
  • GW
    GW Member Posts: 4,831
    no need to drain. At least for this portion of the experiment
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • I doubt if it's the head and think that you will have to drain the system and replace the actual valve.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • ChrisJ
    ChrisJ Member Posts: 16,315
    I might have missed it but what kind of system is this?

    Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.

    Alan (California Radiant) Forbes
  • kcopp
    kcopp Member Posts: 4,472
    Hot water. old cast iron radiator. Probably an old converted gravity hot water system.