I have very little idea about central heating. We have an airlock in the system. The problem with it is that heat seems to be getting to some of the radiators. We turned a few opff last night, and those radiators which had no heat anthem got heat. So what I need to do is somehow cheese the bubble around the system until it can be vented. I’ve bled all the radiators, but I suspect the bubble is in a pipe somewhere.

Any suggestions on how to fix this? I suspect we may have to bleed the system.

Isolate and bleed each radiator individually?

[Edit for clarification] Close off all but one radiator, run the heating system and bleed it; then close that one off and move on to the next.

Where is Stuart when we need him......

Turn off the heating and bleed ALL the radiators. Make sure to refill the boiler to a suitable pressure - 15 mins max and all will be fixed.

Al

We bled all the radiators last night, as in OP.

Anyway, went round the system with the radiator key, and bled each radiator again - no air came out of them, just water. Switched on the system, and there is heat coming through.

We’ll see how that holds this evening when the timer kicks in.

you probably need to balance your radiators.
HTH
Didge

That’s possibly the next job. We have managed to work out that if we turn one radiator off, the rest of them warm up. This house has odd plumbing - if something goers wrong, it’s water related.

Anyway, the further complication is that the muppet who lived here before us was a “handyman” and we are now doubting if the lock shield and the on/off rotating cap (see picture 3 in didgeman’s instructions) are on the correct side of some of the radiators. Other oddities in the house have been obviously this idiot’s attempts to fix stuff up. Obviously we can figure this out as it appears that the lock shield is the water “in” side so should get hot first - is that correct?

Anyway, we’ll give this a go.

Don't forget that the radiators will warm up in sequence so, those at the start get warm before the ones at the end. It takes an age for our last one to warm up. Also if you have thermostatic valves, check they're not stuck shut. Often happens when people turn them off for long periods which you shouldn't really do. We've just moved into a house and I had to free up every single TRV.

Problem solved, it seems!

I didn’t realise you could bleed the pump until today, which I did. I also found another bleeding valve next to the hot water tank (obscurely placed, and it wash”’t obvious that it was a bleeding valve). That let out air for about five minutes when I opened it.

Today, the central heating came on, and all the radiators are warm. Looks like the job’s done.