Central heating

[only_tim]

Recently changed the central heating pump, since then I can't get the downstairs radiators to heat up. Has anybody any ideas?

[woofgang]

possibly a build up of sludge somewhere. Was the system drained down to work on? Try turning it up full chat then go around and drain a little water from the BOTTOM of each rad, about a cup full. this may shift the sludge or you may see that the water is sludgy, in which case drain and flush the system and refil, add fernox or equivalent anfd try again

[LATECOMER]

Sometimes when a system is drained you can cause air-locks to form when you refill. Try turning all radiators off and then just open one off the ones that you are having a problem with this might force the air-lock out.If this works then repeat with all the other affected rads. Then bleed your rads again.

[RAYMAN]

? is the pump working,there could be a airlock in the pump

[BillyNoMates]

Are you sure that the new pump has been set to the same speed as the old pump ? Not that likely but worth checking - most pumps have a 3 speed setting close to where the electrical connection is made.

[only_tim]

In answer to all replies the system wasn't drained just isolated either side of the pump. The new pump is running fine and is on the same setting as the old pump.Thanks for the advice I shall try the other suggestions and see what happens.

[grahamfreer]

have you put the pump the correct way round sounds silly but is very common even in pros