My boiler does not cut out, appears to be overheating and hot water is filling up radiator top up tank and causing overflow. I have changed boiler thermostat, anybody have any suggestions.
Thorn Olympic 20/35c boiler
- Thread starter Lapsleybob
- Start date
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Thanks for the reply, the ball valve is not running all the time, and the water level is higher in the radiator top up tank. The water in the cylinder only gets slightly warm, whereas the water coming from the boiler up through the top up tank is boiling. I would have thought the boiler stat would cut out before this happens. Is this normal for a boiler expansion to be connected to the top up tank.
yes the expansion pipe may discharge into the F&E tank this is quite normal, it does sound as though you have a boiler thermostat fault, when you replaced it are you sure that the sensor Phial was inserted correctly? also have you had any electrical work carried out in your house ? I had the same problem once and the polarity of the electrical supply had been reversed at the consumer unit
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faulty gas valve possibly, check to see if there 230v on the L&N of the gas valve when not calling for heat. if no voltage and the boiler is still operating then the valve is faulty. if there is voltage then the problem is else ware.
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