Over heating Central Heating -Help!

[Stewart Devereux]

Probably see from the time of the message just been woken up by the expansion tank overflowing from the loft- sorted the blocked- the pipe that is curved that runs in from the top missed the tank-assume this is a safety overheating pipe-boiling water was running from it-Why?? Radiator red hot. Emptied some hot from the tank(its a soild fuel boiler, left on over night, water stopped, then turned rads on by moving down the therm on the tank and more boiling water from the pipe. HELP. Surely pump is working-why did water get so hot as to enter the expansion tank? therm seem to work, but was set high-did it just sticks or did the tank just get too hot, and the radiator were unable to cope with the heat, so forced water out. When I turned pump on manually boiling water pumped into expansion tank and help advice appreciated.

-- Regards, Stu Devereux. Fax no. 08701339568 (Outside UK fax [phone]) E-mail. [e-mail]

[noelogara]

most likely problem is pump. make sure pump is running by putting your ear to it and perhaps change the speed with the switch on the side of the pump to ensure its running. It is quite audible when running. hot water would expand into the vent pipe by convection even if all else failed. Thats the reason for the expansion pipe ie to release pressure when the system overheats.

[Keith Willcocks]

If the pump is hot, press the point of a screwdriver against it and rest your ear against the handle. The sound can then be heard without you getting burnt.