Have just fitted a new three way-valve PROBLEMS!

[johnna]

The new valve is fitted and although it seems to be working (It rotates independently) my heating won't come on. I have tried bleeding the radiators and they now seem full of cold water. My pump is pumping.

When I press my boiler ignition switch, the pilot lights and the flames come on but soon go back off. If I hold it in, the boiler boils up but then thuds a few time and cuts out.

HELP! PLEASE!

[johnna]

I have adjusted a tiny little screw above the water pump.

My heating works again!

[johnna]

But it has stopped again BOOOOOO!!!!!

[johnna]

PLEASE HELP!!!!