Radiators half filling upstairs

katy39

Hello All,
We moved our bedroom Radiator a few inches and drained the system to do so, now when we want to fill the system all the upstairs Radiators are only half filling even thou we bled them.
As far as I can see its a a open vented system and the cistern/tank in the attic is full.
Any ideas Thanks.

Pete67

Are there two separate cisterns in the attic? If not you may have the infamous 'semi-sealed' system which fills the heating system from the main cold water cistern via a check valve (one way or non-return valve) These valves often stick closed and there is not much head available to open them.

If you do have two tanks, the smaller feed and expansion tank should not be full, the ballcock should be fitted about 1/3rd of the way up from the bottom of the tank so the water level should be about 1/4 full or so.

Alternatively, could it be a sealed system? Can you post a few pictures?

katy39

Pete67 wrote: »

Are there two separate cisterns in the attic? If not you may have the infamous 'semi-sealed' system which fills the heating system from the main cold water cistern via a check valve (one way or non-return valve) These valves often stick closed and there is not much head available to open them.

If you do have two tanks, the smaller feed and expansion tank should not be full, the ballcock should be fitted about 1/3rd of the way up from the bottom of the tank so the water level should be about 1/4 full or so.

Alternatively, could it be a sealed system? Can you post a few pictures?

Thanks for your reply Peter, the air eventually worked its way out , Thanks again .