Radiators and TRVs - can't understand what's going on.

[shaft1]

Can someone please help me understand what is going on?

All our radiators (except one) have TRVs. They've been working fine until recently when 2 TRVs stopped controlling the radiator temperature and these radiators get very hot and stay hot doesn't matter what number the TRV is set at even if you turn them to zero.

However, if these 2 TRVs are set to zero BEFORE the central heating is turned on then the radiators stay cold until you turn them up and then they stay hot even if you bring the TRV back to zero. Hope that makes sense.

Has anyone experienced something similar? Are the TRVs definitely faulty and need replacing or is there something else going on?

Any help will be much appreciated. many thanks

 

[Boilerman2]

Sounds like they are faulty to me, sounds like they won't shut down once water is circulating artound system but if the heating is off they will then seal

Replace them with a decent make i.e Danfoss or Honeywell

 

[shaft1]

Sounds like they are faulty to me, sounds like they won't shut down once water is circulating artound system but if the heating is off they will then seal

Replace them with a decent make i.e Danfoss or Honeywell

Thanks boilerman2. I've already bought Danfoss RAS-C2 TRVs but didn't want to fit them and find out that the problem is not with TRVs. I was hoping someone will reply and say "that happened to me and it's definitely the trvs".