Isar he24 boiler no heating only hot water the c light is on the display for central heating but he boiler light is flashing blue Help!
Your scenario doesn't seem possible 'sav' IMO Unless you have a thermostaticly controled tap and that is faulty. If the boiler stays alight the heat has to be absorbed somewhere. If it's not pumping down the ch flow then I'd be checking the gas rate! If it's modulating down and the h/w is not +35DegC Then suspect the h/w temp sensor providing you are gettingenough gas supply!
