Heating won\\\'t refill

I\\\'ve been trying to refill my sister\\\'s central heating. Everytime a radiator is drained, the water is lost from the system.

Checked the header tank and it was dry, so fixed that, but still the system is not refilling from the tank.

I disconnected a radiator and drained down the water from the system (keeping the radiator valves closed to save the water that was still in them from being lost too) and the header tank drained.

I replaced the radiator which only filled once I opened up an upstairs radiator. The system is now filled at ground floor level, but all the upstairs radiators are full of air (probably the top 3/4s).

I\\\'ve checked the bleed valve in the airing cupboard and there\\\'s no air coming out of that and I made sure the motorised valve was open.

Any ideas anyone?

If you do a search on "blocked cold feed" you'll find similar tales of woe..

Paddy C said:

...I disconnected a radiator and drained down the water from the system (keeping the radiator valves closed to save the water that was still in them from being lost too) and the header tank drained.

Click to expand...

So the cold feed is not blocked, try closing the flow valve to each upstairs rad and bleeding the air out (water should come through the return end). This may dislodge air from the return pipework and cure your problem......but.....if the pump's on the return do this without the pump being on.

i got an idea

like wot is the fekkin question?

[blockd air bleeds?

wilhelm said:

i got an idea

like wot is the fekkin question?

Click to expand...

now now will

Not at all sure that your hot water heating systems are the same as ours, but...

A hot water boiler operates at a much lower pressure than the potable water supply pipes to your faucets...

...and that means there has to be a pressure reducing valve on the cold water feed line to the heating system to ensure that the heating system doesn't get up to the water supply pressure and crack your boiler.

... and over here, those pressure reducing valves will have a sediment screen inside them that prevents any sand or rust or what not from getting into your heating system with the incoming cold water.

... and those screens will often get clogged, preventing the cold water from getting into the heating system. (This is in fact a commonly overlooked problem over here because lots of homeowners don't realize there's a fine filtration screen inside that pressure reducing valve, and end up monkeying with the pressure setting on the valve before realizing the real problem is a clogged screen, and then spend days trying to get the pressure setting back to where it should be.)

But, I'm not sure if our heating systems or pressure reducing valves are similar to the kind you have.