Radiator Question

[jonwm]

Bit of a strange one so thought I’d ask her before calling in the plumber!

Got 2 radiators downstairs that don’t seem to be heating up fully compared to the rest of the house, they are both quite new (less than 2 years old) 1 is manageable but the other is in a colder room so really noticeable.

So as you look at it the pipe on the right with a standard valve is feeding it hot water, pipe is hot to touch, radiator is warm to hot on the top but like warm at best halfway down, and below, pipework on the left has a trv and the pipe work is warm easily can hold it tight with no feeling of pain associated with holding hot pipe :-)

Don’t think it’s sludge as it’s quite new and system was cleaned out not that long ago, have 5 other radiators that are red hot to touch all over, all older than this one.

Any advise appreciated

[anonymous-user]

The central operating pin on TRVs can sometimes seize. Try removing the valve head and work the pin up and down to free it off.

[CorradoTDI]

As above but take it you've bled it?

[anonymous-user]

CorradoTDI said:

As above but take it you've bled it?

It wouldn't be hot at the top if it had air in.

As above check TRV pin is free, but I wouldn't work the pin up and down I would just tap it with a spanner, if you work it up and down it can break or remove itself from the valve causing a whole world of pain.

[anonymous-user]

Could be a balancing issue?

I would close off your old rads and see if the new ones heat up. If that works then turn on the old ones until all are hot enough.

This happened to my parents when they had 2 new rads - the hot water never made it to the new Ines until I did this for them.

I am not a plumber!

[g7jtk]

Turn the upstairs rads off and see if that gets things moving

[Dave_ST220]

garyhun said:

I am not a plumber!

That's good as most of the useless s don't even bother to balance a new system anyway. Correct balancing is the key to an efficient & fully working system.

[jonwm]

Thanks for all the replies.

I'm currently doing a live test as i'm typing, not had chance before now, so all upstairs rad's off apart from bathroom which is a non trv towel rail, so the inlet pipe with normal valve is red hot to the touch, exit pipe with Myson TRV on it is warm at best, do we think its the TRV?

I'd say the top of the rad is hotter than the other day in a much shorter time, but bottom is still just warm.

[jonwm]

Update 2,
Felt brave and unscrewed the top bit of the TRV, the pin seems free on the actual valve, so stuck the heating on again and hey presto the radiator is red hot and the return pipe is too.

So looks like it was the TRV at fault, now questions:

Will my system now be out of balance as i've had all the radiators upstairs off whilst running it? (just turned them back on)
Can i get a replacement top and leave the top of the TRV off for now?

Thanks

[g7jtk]

jonwm said:

Update 2,
Felt brave and unscrewed the top bit of the TRV, the pin seems free on the actual valve, so stuck the heating on again and hey presto the radiator is red hot and the return pipe is too.

So looks like it was the TRV at fault, now questions:

Will my system now be out of balance as i've had all the radiators upstairs off whilst running it? (just turned them back on)
Can i get a replacement top and leave the top of the TRV off for now?

Thanks

C

Yes you can. The point of closing the upstairs rads was to force the head downstairs. Now you know that it works you should put the heads from ground floor upstairs and vice versa. This should prove whether it is the heads or the valves at fault.
A drop of WD40 on the pin and work it up and down of a few light taps would do no harm either.
Now balance the system once you are happy it all works.