Airlocked CH system

[OJ]

I drained down my central heating system to replace a 3-way valve....and now my system seems airlocked - loads of loud clunking sounds, etc.

I am only getting heat in 1 upstairs rad and no downstairs rads. The header tank has very dirty (hot) water in it, and the expansion pipe is spluttering into it every now and again.

I turned the boiler off, and re-bled all the rads, but it makes no difference.

Any advice would be appreciated....

 

[twgas]

try draining again but dont turn water to f&e tank off, then you can check if said tank empties, if not you have a blocked cold feed.