The device which controls the flow of hot water from my boiler to the coil in the cylinder is a TRV, set to 6 and connected to rudimentary temperature probe held up against the side of the cylinder. This, due to the hard water where I live has acquired the habit of sticking shut so periodically we don't have hot water and I have to fiddle about with the TRV to try and free it. There must be a better solution than this, surely ? Can anyone suggest anything please ? I intend to replace the whole system in spring next year when extending the house so I don't want to spend a load of money now, I suppose that I may end up having a new TRV fitted.
Thanks