Noisy Radiators

[dave12]

Ok heres my problem, When my heating comes on some of my radiators start banging. The temporary fix for this is to turn the temp valve a little.

I have been told the cause of this is that the temp valves are on the wrong side. How do you know this? Do I need to swap the temp valve around? How do I do that?

Sorry for all the questions at once.

Oh I have a Combi Boiler if that helps at all

Thanks in advance for any help.

 

[AL]

You say the valves are the wrong way around? I take it you have a lock shield on one side and a Thermostatic valve on the other? If not, you probably have to lock shield valves one with the +/- cap on it and the other with a plain non adjustable hat. These do come off and can be changed round if that is the case? How do you know they're the wrong way around? You may need to rebalance your system too?

 

[dave12]

Thanks for the really quick reply,

Sorry for being a little vague. I have a Thrmostatic on one side and what I think is a lock shield valve on the other (with the small white cap on).

I was told that the Thrmostatic valve should be on the opposite side to where the hot water comes in, that doesn't make sense to me

 

[AL]

so who put them on that way around? Was it like that when you moved in. AFAIK the lockshield should be on the input pipe and is used to balance the system (to limit the water flow into the rad) and the output pipe should have the thermostatic valve on it so you can fine tune the flow of water through the rad from no flow to max flow allowed by the lock shield. Think i've got that right, but i'm no expert.

I'm not sure why this would cause a banging noise though? Banging noises are usually caused by moving pipes hitting the floor boards or kettling boilers etc?

i suppose if the thermostat valve is fully open you could be getting a large flow of water rushing into the rads at the start of the circuit causing some noise. When you say you turn the valve to shut them up, are you turning them up or down?

AL

 

[dave12]

Cheers AL your explantion seems to make sense. And you assumed correctly I have just moved in to the place. So Luckily I don't have to be too embarrassed

Could the banging be the valve trying to close? Maybe theres to much pressure on the valve at that point. I suppose it make sense as when I turn the valve up it stops. So when opening it allows the pressure to go through and when I turn it down the noise stops but only for a while. What do you think?

 

[AL]

not sure really, wait and see what the experts of this forum reckon

come on guys

AL

 

[corgiman]

probably is the TRV's (thermostaic rad valves)

if you look at the TRV there will be little arrow showing which way the flow of water should go.

to check which way it is turn the boiler and feel

the noise you hear is the jumper in the TRV vibrating against the water flow and can be very loud. if this is the problem I would not bother in swapping the valves around but replace them as the ones you have must be a tad elderly not to be biflow mate

Alternatively leave them fully open as this sometimes works

 

[dave12]

Thanks for all your help AL

corgiman, Ive checked my radiators and you were right. There is an arrow on them I couldn't see it because it was on the wall side (so I used a mirror!) . The ones that make a noise are the wrong way except one which is supposed to be a Biflow (two Arrows). This one must be knackered?

If I replace the valves do I need to Drain the sytem even though its a closed system, off a combi Boiler?