air in radiator

[spanglehead]

Can some one help please.....two plumbers in, no fix!

The furthest upstairs radiator from the boiler keeps getting air in it. Now here's the puzzling bit. When I open the wee valve at the top to bleed the air out nothing happens. If I turn the TVR to closed and wait, then air will start to come out very slowly. Leave it for a bit and then turn the TVR up to 5 and the air will start rushing out. Sometimes though I feel that air is being sucked IN to the wee valve at the top when I open it up. However the rad stills keeps gradually filling up with air and has to bled every couple of weeks. I've had two plumbers come in and scratch their heads, they haven't been able to find out how air is getting into the system. Any suggestions?

 

[45yearsagasman]

Are you able to describe the system setup in the airing cupboard in more detail assuming you have one.Maybe a pic.Without more info its very difficult to help.

 

[spanglehead]

we don't have an airing cupboard. the hot water tank is in the kitchen. We have recently converted from solid fuel to oil, but the radiator problems persist. We have solar panels to provide hot water but they only go into the hot water tank and there shouldn't be any connection to the central heating system.

 

[spraggo]

It seems that the central heating pump is situated in the central heating return pipe, if this is the case, when you try to bleed your up stair radiators with the pump switched on it will suck air in through the air vent. So try switching the pump off before you open the air vents. This problem will be magnified if there is a restriction in the feed pipe from your expansion pipe in the loft.