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General Plumbing and Gasfitting Talk => Ask Plumbers (Public) => Plumbing => Q & A - Hot Water Cylinders => Topic started by: iain.d.waugh@gmail.com on March 08, 2016, 09:30:25 AM

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Title: HW cylinder is overheating to boiling point
Post by: iain.d.waugh@gmail.com on March 08, 2016, 09:30:25 AM

my hot water cylinder is over heating and boiling, it over flows from the roof vent and is scalding hot from all taps and shower. have replaced thermostat several times and also the element, i switch the power off and wait a couple of days to turn it back on to re heat the tank. when i replace the thermostat i make sure i can hear it clicking on and off at the set temp but still randomly it over heats....this is a metal craft cylinder, 180 litres. any suggestions out there before i get the whole thing replaced?

Title: Re: HW cylinder is overheating to boiling point
Post by: robbo on March 08, 2016, 04:08:15 PM

ay a guess i would say that it is an old cylinder and the Thermostat Pocket has a lot of calcium or similar build-up on it that does not let the thermostat ever get the correct temperature,cheers 

Title: Re: HW cylinder is overheating to boiling point
Post by: Steven Tyler on March 12, 2016, 05:21:26 PM

I think, the thermostat cylinder is not matching up with the heater. That's why the problem is rising again. For this, you need to ask the expert first. 



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