radiators air locked

ginger_nuts

my aunt has 8 radiators ,4 downstairs and 4 upstairs .The upstairs radiators are all air locked ,the kitchen radiator was air locked ,I bled it but there was some air in it an hour later .I tried to bleed the upstairs radiators but only a small amount off air comes out . All the radiators have individual thermostats if that makes any difference

Canucklehead

Hi

Does the upstairs rad bleed air then water or just stop and you get nothing?
Sounds like the system is running dry, if it's a open vented system. (small tank in the roof)

Corgi Guy.

ginger_nuts

Canucklehead wrote: »

Hi

Does the upstairs rad bleed air then water or just stop and you get nothing?
Sounds like the system is running dry, if it's a open vented system. (small tank in the roof)

Corgi Guy.

the upstairs rads bleed air then nothing

SilverScooby

Is it an older gravity system where the pump sucks the water through from the end, rather than a modern fully pumped system where the pump pushes the water through from the start? (very badly put but I hope you can see what I'm getting at.

If so you must make sure the pump is off when bleeding, otherwise it just sucks air in

I made this mistake myself and felt a real idiot when British gas came out!

Canucklehead

Hi

I'll assume you have a small tank in the roof . Go up and see if there is water in it.If not move the arm of the ball valve up,down and let it fill .The system will fill.( after all is settled down go back and make sure the tank is not overflowing to outside)
If the tank is full then you most likely have a blocked pipe at the point where the water from the tank meets the heating pipework. It'll need cutting out and re- piped.

Corgi Guy.

quacker_2

I was told by the chap who installed my central heating to switch off the system when trying to bleed the upstairs radiators? try that and see if it helps.

safesound

Canucklehead wrote: »

If the tank is full then you most likely have a blocked pipe at the point where the water from the tank meets the heating pipework. It'll need cutting out and re- piped.

I have exactly this problem (sorry for high jacking your thread ginger_nuts), how do I know where they meet? I need to replace my boiler too, do you think I should replace the whole piping system at the same time or just where (hopefully) the blockage is?

Canucklehead

Hi

Follow the pipe from the roof down . Usually ends up in the airing cub. with the cylinder.
15mm cold feed 22mm open vent.
It might go back to the boiler, depends on the installer and where the boiler is fitted.
Unless you have stainless steel pipework or it's very old then no need to replace all the pipe ,just make sure its all flushed through.

Corgi Guy.