Ok this is the problem ,
rads upstairs get very hot,
ones downstars do not get hot,
i have left heating on for hours ,
have changed rads and valves ,
i put the heating on and waited for the upstairs rads to heat up,
i then shut the valves off both sides on them ,

but then the boiler fires up and cuts off after 30 seconds ,
it then comes on again about 1 min later and fires up for 30 seconds then shuts off again and so on and so on ,
i do have a small and i mean very small drip from the heat exchanger ,
but if i reopen the valves on the rads upstairs the boiler cuts back in and runs until the rads upstairs are nice and hot then cuts out ,
but still the rads downstair do not get hot ?????

the hot water is working ok we do not have any problems with that ,

Brian R, September 2007

shut the rads off upstairs, and the water will be forced down stairs. then bleed rads and open teh upstairs one by one. only open the valve by one full turn on valve

mr worcester, October 2007