the problem is as follows, when i swithch on my boilerthe pump runs (not sticking) and it ignites heats up then when at temperature switches off then on every thirty seconds or so as it hetas and cools,but the water doesnt circulate heating the radiators and it sounds as if there is air in the boiler.my radiator has the old type of bleed on the bottom inlet / outlet pipe any advice on how to bleed the system would be greatly appreciated

geordie jim, December 2008

thanks for that gary the tank is full, although I had drained it sometime ago and I think this is how air got into the system so I was thinking that maybe it has become airlocked, I just havnt got a clue how to get the air out again, any help again would be greatly appreciated

Geordie Jim, December 2008

Sounds like the system is running dry. Check the header tank in the loft, the ball-valve may be stuck and the water has evaporated over time.

Gary C., December 2008