central heating problem

I have a Potterton Suprima boiler and yesterday the central heating pump died, i have changed it but now when i start the heating the waer pump starts the boiler lights up and then about 30 seconds later there i a banging sound from the pipes, the boiler goes out and not one of my radiaors is warming up. Help

Will be an airlock in pipes.

how do i get rid of it ???????

Have you any air vents near to pump?

Is it a vented or pressureised system?

All i know is its Pottertron Suprima 50 wall mounted fan assisted gas boiler.

From what I can gather that boiler is a heat boiler (you have stored hot water), so either you will have header tanks (in loft) or you will have an expansion vessel (near HW cylinder)

yes have a tank in the loft....

Has the tank got water in it?

yes checked

Firstly you need to make sure that you opened any isolator valves back up that you might have shut while changing the pump,

then check for any air bleed screws/valves and open them until water comes out... you could also have air trapped within the pump, so slacken off the big chrome screw on the back of the pump until all air is removed..

If you still have an airlock after doing that, come back and either I or someone else will talk you through pushing it out with a hose!

Done all of that earlier and no luck. I checked the pump and bled it and no air in it. Only other bleed points i can find in house are on the radiators, but there is no air in them.

The only way now then is to try and force mains pressure water through it to push the air out

This is what I'd do..

Make sure all your radiator valves are open

then find the header tank for the heating side (usually the smaller of the two) and then identify the expansion pipe,, connect a hose to the expansion pipe and to a cold water tap and slowly turn the tap on.. this will force water through the system and it will start to fill the header tank through the outlet (any air should come out here also),,, allow it to do this for 5 mins or so - it'll overflow through the overflow pipe (that's expected) just don't allow it to overflow the sides of the tank

If you are unsure as to what you are doing then get a plumber

HTH

Think have to get plumber in tomorrow, well above me....

Good description Noz - "scoob" for you, methinks........

Use your powers of divination to find the airlock :slap

Have you made sure you've bled the tanks heating coil? There should be a bleed point next to the tank.

Try the pump in the highest speed as this can sometimes push any airlocks you have out of the pipework into the rads which you can then bleed.