Central Heating Issue

Soldato
Joined
23 Nov 2004
Posts
3,790
Hi,

One of my radiators was struggling to get warm, but mainly in the bottom half. I bled all the radiators thoroughly, and with it being at the bottom I suspect the issue wasn't air.

I put in some Sentinel cleaning solution from Screwfix (Sentinel Rapid Dose X400) for 4 weeks, but it didn't improve. Today I did the following:

- Connected hose to radiator drain valve
- Isolated all other radiators (by closing flow and return valves)
- Opened the radiator drain valve the hose was connected to
(Water drained out, seemed clean. Opened blead valve and a bit more came out, but no dirty water)
- Turned the valve under the boiler on to put water back into the system and to flush through the radiator and back out through the hose. The water came out fast and wasn't dirty
- I then repeated this for all of the other radiators (only 6 as I'm in a ground floor flat)
- Closed the valve and removed the hose
- Filled the system back up to 1.5 bar
- Tried central heating again
All radiators were piping hot, except for that one, again, at the bottom! ARGH!!

So, I've just done the following:

- Drained said &*@%$ radiator and flushed it through with the hose. Water came out fast from both bottom holes and no sludge/black stuff came out
- Removed blead valve completely and still the water flowed freely

So what could be the issue? Is the blockage in my return pipe from that radiator? Am I to assume that is the last radiator in the circuit as its only that one that is affected?

I should also say, the boiler is a Combi, and the pipework for the radiators is very thin, think its called microbore.

Suggestions? PLEASE??! Thanks :)
 
I had a similar problem and it could be something like it's one of the end radiators and your other radiators are on too hot? I turned some of my other one's down and it fixed it.

It's summer anyway, turn them all off :p
 
I had a similar problem and it could be something like it's one of the end radiators and your other radiators are on too hot? I turned some of my other one's down and it fixed it.

It's summer anyway, turn them all off :p

I don'r need the heating, but I know the issue was there and I've got some days off work so I wanted to sort it. :p
 
father-in-law had similar issue. the one causing an issue turned out to be the last radiator on the system. most of the other radiators were opened fully on their valves so he turned them all to about 80% and then the last radiator got hot like the rest:)
 
Your system isn't balanced.

Try opening the lockshield on the slightly cold rad a bit, if that doesn't work close it back to where it was and try closing the lockshield on the others a smidge.
 
Back
Top Bottom