The expansion tank water in my mates central heating system is getting hot, to the degree that the steam is has caused massive condensation in the roof space what can cause this and how can i remedy this, i have turned the boiler heat control down. still wrong

pat shine, December 2008

I would like to thank Kenny F and Tony S for their replies to my question. It turned out someone had set one of the valves into manual mode and held it off.
This is what a plumber said and it seems to be o/k now.

Thanks

pat shine, December 2008

Pat.
As below mate except make sure that the thermostat is working. are you having to press the red button on the boiler to restart it? what temp is the water getting to compared with the stat setting?
is this a new system? has this always happened?
how high is the tank above the level of the highest rad?
If it continues after you turn down the pump speed you may have to raise the pipe for the vent or even check whether you can swap over to a pressurised system and use an expansion vessel instead, this takes a bit of calculating though. some websites do handle this and you could google the question if you feel the need to go there.

Kenny F, December 2008

Check the pump speed.If its set too high it will pump over.

Tony S, December 2008