I know this will be difficult without actually being there.
My daughters two storey house has a large single story extension across the back of the house, approx 4 x 12 mtrs
The heating was not very good when she purchased it, so she did have the system cleaned and supposedly had it pressure cleaned. Quite a lot of dirty water came out, but since then only certain radiators get warm, whilst others stay cold.
She recently had the large extension opened up between the extensions dividing wall whilst blocking up the opening to the old lounge.
Two new tall radiators were fitted, one in each side/room of the extension.
Neither radiators get warm although water is getting to both as the bleed valve proves. Heat reaches the inlet valve of one radiator and very slightly warms the top 1/2". The other stays cold. The old radiators were about the same. When I checked the bleed valve, the water squirted out, not dribbled.
The radiator in the bedroom adjacent to the extension, in the original house, is cold.
At first I thought maybe the boiler is too small to heat the extra pipework, but as heat is reaching one inlet on the new radiator, I have decided maybe it is okay.
The pipework is 10/12 mm (I have not measured to be honest).I am thinking maybe there is more sludge in the system than came out when cleaned, maybe a blocked radiator or two, but I thought that the water would still circulate even though one or two are blocked.
The plumber that fitted the radiators has put a cleaner in and told her to leave it a few weeks and he will come back. Trouble is winter is getting closer and she could do with some heating.
The house is about 20 years old if gives some idea of the system fitted. There is also what looks like a pressure tank below the boiler if that helps.
The plumber said he thought if the cleaner does not help, he might have to start digging out plaster to fit larger pipework, but again, as the water is getting to one radiator, I am not sure 15mm pipe would make much difference, if at all.
I am thinking (although I am stabbing in the dark), give the system a good power flush and/or trying to work out if blocked radiators are the problem.
I think the house is probably 145 sq mtrs 4 bed, integral garage.
Can anybody suggest any ideas of what could be wrong?
