DIY Doctor UK DIY Forums

Help. I have no hot water or central heating after fitting a new radiator. I drained down the system after turning the mains off, removed the radiator, fitted two new valves and the new rad. Re filled the sytem and bled all the rads,hey presto nothing. I thought it might be an airlock so I then topped up the system from the drain point next to the boiler using mains pressure. This eventually came out of the overflow in the header tank. Still no hot water or heating. I then bled the central heating pump, still nothing. I then bled the nipple next to the tri valve situated above the central heating pump ( approx 15 buckets worth) still nothing. Re bled the rads, nothing. The boiler seems to be firing up when it is turned up. The pipe is very hot on the outlet from the boiler but as you follow it up the wall it becomes cooler. Can anyone suggest anything that I,ve missed as I have been at this for two days solid now?

This is an airlock, and just undoing the little bleed valves is not enough to cure it. You need to seriously let some water out to shift the air. You need to undo a coupling and let out a gallon or so of water from the boiler feeds. Turning the pump round temporarily can clear airlocks.

Hi Paul,

Have you shut any valves & forgot to reopen them?
Does the pump turn?
Electric to all necessary parts etc?