Cold radiator pipe

Luckysasha

I have an on-going issue with a radiator not heating properly. The top of the rad is marginally hot and the bottom 1/3 of the rad is cold to the touch. I noticed today the the pipe going to the TRV is very cool while the pipe going to the lockshield valve is hot. The plunger on the TRV is free and not jammed and the lockshield valve is open. Any ideas ?

Wearb

Turn off one valve and see how much flow you get when you bleed rad. Then do the same at other side. It might highlight if one side has a restriction.

TPM

has this rad ever heated properly?

Does it improve if you turn off some of the other rads?

a rad heating at the top and cold at the bottom is a circulation issue.

Luckysasha

Worked fine until last winter when we noticed the room was colder. Seems to be worse this year as we have the heating on more now the weather is getting colder. Rad was moved approximately 5 feet last year but pipework all seems ok, no leaks. I tried turning off all other rads and no luck I even tried turning off the balancing valve on the hot water coil at he cylinder but no change either. I thought it was a build up of sludge in the offending rad but when I bleed the valve the water runs crystal clear.

Dtp1979

Luckysasha wrote: »

Worked fine until last winter when we noticed the room was colder. Seems to be worse this year as we have the heating on more now the weather is getting colder. Rad was moved approximately 5 feet last year but pipework all seems ok, no leaks. I tried turning off all other rads and no luck I even tried turning off the balancing valve on the hot water coil at he cylinder but no change either. I thought it was a build up of sludge in the offending rad but when I bleed the valve the water runs crystal clear.

I've seen sludged up rads bleed clear water. Quite often actually. That doesn't mean thats your problem though.

Luckysasha

If there is sludge in the rad why would the TRV pipe be cool ? If I take the rad off and flush it would I be aswell open the TRV and let some water run through in to a bucket before I refit the rad ?

Dtp1979

Luckysasha wrote: »

If there is sludge in the rad why would the TRV pipe be cool ? If I take the rad off and flush it would I be aswell open the TRV and let some water run through in to a bucket before I refit the rad ?

A temporary solution but it's probably work. If it is sludge it's not going away from your system as a whole.

Luckysasha

I was thinking if there is sludge in the rad then probably the next step is to power flush the whole system. The heating system is only 5 years old would sludge occur that quickly

Dtp1979

Luckysasha wrote: »

I was thinking if there is sludge in the rad then probably the next step is to power flush the whole system. The heating system is only 5 years old would sludge occur that quickly

It shouldn't but I have seen it. It's unlikely but not impossible