I had to change my pump so I swtiched off all the water and drained the system. I could not find the fill loop valve so I jsut turned off the water at the mains. I have refilled my system and bled all the rads but now my boiler only comes on for a minute then shuts down. someone has suggested there might be a blockage in the cold water suppy to the boiler? How do I check this?

Mr john Kennedy, February 2009

it sounds to me as though the pump is not circulating, vent the pump through the screw at the front. and vent all rads and bleed taps any where on system untill it is working. some times its better to let things settle 1st for a night or so then bleed everything again untill its working. if the rads/system/ boiler are full then its not a blocked cold feed. sometimes the boiler can get airlocked depending on its position.hope this helps. you may have to drain and refill

john, February 2009

sounds to me like you have got an air lock in your system.try and get any air out of the pipework especially where it may rise. if you take a radiator off making sure you have turned the valves off and open a rad valve into a bucket and try and pull it thru .

ksheating@googlemail.com, February 2009