One radiator will not stay hot

[Jason Hill]

My living room radiator is cold when all the other radiators are firing. I have checked all the internet YouTube advice feeds. The trv is working correctly, the lockshield valve is also working and I have taken the radiator off and flushed it through and have bled it. I believe it is the furthest from my combi boiler. I have turned all my other radiators off and this makes the living room radiator work, but as soon as I turn one other radiator on the living room one goes back to cold. Any further DIY advice would be much appreciated. Thanks Jason

 

[ShaunCorbs]

Sounds like you need to balance the system

Croppie's Balancing Thread.

 

[king of pipes]

Just follow croppies thread he coverd it very well cheers kop.

 

[Jason Hill]

My living room radiator is cold when all the other radiators are firing. I have checked all the internet YouTube advice feeds. The trv is working correctly, the lockshield valve is also working and I have taken the radiator off and flushed it through and have bled it. I believe it is the furthest from my combi boiler. I have turned all my other radiators off and this makes the living room radiator work, but as soon as I turn one other radiator on the living room one goes back to cold. Any further DIY advice would be much appreciated. Thanks Jason

Thanks for your advice. I followed it to the letter. As I got to the living room radiator last and fully opened the valves it still does not heat? Any further advice would be much appreciated. Thanks Jason

 

[townfanjon]

Possibly a tired pump pal

 

[snowhead]

How many radiators in total and what size is the boiler and how old is it?

 

[king of pipes]

Uprate the pump to a Dab Evosta pump mate i get mine from plumbcity under a £100 that will shove it round . cheers kop

 

[Last Plumber]

Sounds like undersized pipework.

What size is the pipework to the rad? is it the same as the pipework to the other rads?

 

[Jason Hill]

Thanks for all your replies. To answer all of them, 10 radiators, the boiler is a main combi eco 30 GC number 47_467_03 , installed in 2008. The pipework is 15 mm to all the radiators. If you all agree it probably needs a new pump then I'll get a plumber to sort it. Thanks Jason

 

[steadyon]

If the pipework to all radiators is 15mm I would suspect that is the problem. However, you may mean the pipework visible (e.g. floor to radiator) at each radiator is 15mm. If this is the case, it may be there is a "backbone" of 22mm (or larger) flow and return pipes, with a "tee" off to each radiator. If accessible, look under the living room floor boards and see if the pipework is 15 or 22mm

If however the problem radiator has been added to the system and is connected to another radiator by 15mm pipes, that could be the problem, as could a radiator being added before the problem one and bridged across the original 15mm pipes.

Replacing the pump might do the trick, but I don't think anyone could guarantee it.

Is the problem radiator a standard type, or is it a vertical "designer" type?