I went round bleeding all the radiators with the CH on. Two tall rads were a really slow to bleed so I turned the pump speed up. Probably a bad idea. When I got to the bathroom it got quite noisy and I looked at the boiler and it was indicating 99 degrees. It's a Worcester Greenstar HE, about 15 years old, though many of the rads could be twice that. It doesn't seem to have expanded boiling water into the header tank. I turned it off promptly but I suspect I've dislodged some sediment in the pipes. It was serviced earlier this year. Is there anything I can do which doesn't involve major dismantling until I can get an engineer out?
boiler temperature went sky high bleeding rads
- Thread starter andyv1
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If you don't have a water tank then you will have to top up the boiler via a filling loop usually located under the boiler.
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Which "header" tank are you referring to ? Is it a feed and expansion tank for the central heating ? If so ,does it have water in it ?
When boiler showed the sky high temperature ,were all rads excessively hot ?
When boiler showed the sky high temperature ,were all rads excessively hot ?
Why do you suspect that? Is the system working normally again now? If so, what's the problem?6
I don't see why bleeding the rads or turning up the pump speed would cause the high temperature, but it should have gone off on control-stat and limit-stat before 99°.
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Sorry I wasn't clear. This is a gravity fed system with a header tank and it's got water in. There's an expansion pipe which drains in to the header tank and this wasn't hot at the tank. There's some sediment in the tank however so I wondered if this might have caused the problem. I had a drowned rat in the tank a while back. When I came to take it out it completely dispersed into a brown mess and I wasn't able to fully clean this out.
It's not quite back to normal yet. I turned it back on after letting it cool and it promptly went up to 99 degrees but the flame symbol went out. Then it went into its usual start up procedure. It's still a bit noisy but it's not boiling, some I'm hopeful it'll be OK until the next service.
Thanks for the reassurance. I think my boiler is cleverer than I'd imagined.
It's not quite back to normal yet. I turned it back on after letting it cool and it promptly went up to 99 degrees but the flame symbol went out. Then it went into its usual start up procedure. It's still a bit noisy but it's not boiling, some I'm hopeful it'll be OK until the next service.
Thanks for the reassurance. I think my boiler is cleverer than I'd imagined.
Cold feed blocked where it joins pipework
Either the cold feed is blocked at the 'H' or you have dislodged something into the pipework and there's now a circulation/blockage issue
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