Hi, I too have the same problem. An engineer has diagnosed a temperature sensor, this has been replaced - now have hot water without switching the boiler off, fingers crossed. Also diagnosed that an inverter valve was needed; this should pump the hot water round the boiler and not into the radiators when the heating is switched off. There is a pipe which comes out of the left hand side of your boiler at the bottom, this should be cold, if boiling hot you may need a new valve. Not cheap! but if it fixes it, all good.
potterton performa 24 heating very hot, hot water luke warm, fitted new complete diverter valve, hot water sencers as well, can u help me plz
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