Central Heating (Radiator) Problem

[Dazkb]

As Winter will soon be here and I have had my Central heating off,

thought I better test out the system to see if it was ok and sods law have a problem with one of my radiators on my central heating system th actual system works fine and is about 2 years old for some reason on rad gets really hot where the others do not. Each Rad has a Terrier I Thermostat on (as the regs state you must have these on all ne installations) the themostat on the dodgy rad even if i turn it righ down still gets really hot. could this be a faulty thermostat on thi rad or could anything else be causing it, also if it is the thermosta how easy are they to replace as Screwfix do them and there bound to b cheaper than getting a plumber in to fit it.

your thoughts please

thank

-- Dazkb

[Dazkb]

As Winter will soon be here and I have had my Central heating off,

thought I better test out the system to see if it was ok and sods law have a problem with one of my radiators on my central heating system th actual system works fine and is about 2 years old for some reason on rad gets really hot where the others do not. Each Rad has a Terrier I Thermostat on (as the regs state you must have these on all ne installations) the themostat on the dodgy rad even if i turn it righ down still gets really hot. could this be a faulty thermostat on thi rad or could anything else be causing it, also if it is the thermosta how easy are they to replace as Screwfix do them and there bound to b cheaper than getting a plumber in to fit it.

your thoughts please

thank

-- Dazkb

[Set Square]

My first reaction was that your system has probably never been balanced properly - and whilst that may still be true, the chances are that you've

*also* got a problem with a TRV (thermostatic radiator valve) - because the rad shouldn't get hot if you turn it right down.

TRVs are in 2 parts - the wet part and the head. The head contains a wax capsule which expands when it gets hot, and presses down on a pin protruding from the top of the wet part - cutting off the flow. The head may be faulty. If so, you should be able to replace it without disturbing the wet bit.

You should have been supplied with a manual head to fit in place of the normal one when you want to close the valve positively - for example when removing the rad to decorate. You can check whether the wet part is ok by fitting this manual head and screwing it down. If all is well, the rad

*won't* then get hot.

Once you're sure that all the TRVs are ok, you may *then* need to balance the system to make sure that it warms up evenly, and that some rads don't get hot a lot sooner than others. If necessary, come back here for advice when you're ready to do that.

[Richard Conway]

As an addition to that, if you don't have the original decorating cap, you could always (assuming you have the same type TRV on another radiator) swap the TRV with another radiator. You should then see the problem move to that radiator and will have established the problem!

[Set Square]

Good idea - just swap the heads, of course - no need to disturb the plumbing.