Suspected air lock

[sdsparks]

Evening All

Recently called out to a house with a suspected cracked tank, the tank in the 3rd floor loft space had already been isolated and drained. Further inspection indicated that the tank wasn't cracked and that the valve was spraying water over the top of the tank so replaced float valve for new. Re-filled tank, no sign of leeks but no water coming out of taps.

The tank has two feed pipes, from what I can see one feeds a cylinder in the basement, the other feeds a number of cold taps on lower floors. Basement hot tap is fed from a combi, the primary circuit is valved off to cylinder and heating system, cold in basement is mains, ground floor has toilet with hot from Combi, cold from tank. Second floor bathroom is entirely gravity.

Run out of time tonight to fix problem but my thinking is to blow mains water into the bath mixer tap which is a mono block, this should then blow air out of both the cold feed and the hot?

I find it odd that both feeds from the tank have airlocked but they have

Any thought or suggestions welcome.

 

[WaterTight]

Sounds like an unusual set-up. What boiler is heating the water for the clynider then? Could be blocked cold feeds. They scale up and up until there's a highly reduced internal bore and then on draining the tank few bits of individually insignificant bits of rubbish get dragged down and block the bugger up.