not hot

Hi folks, Basic set up no timer or external components. No issues whatsoever with hot water which got a new thermistor from me recently due to its having failed. Previous owner had boiler regularly serviced and seems otherwise in good shape. Switch on boiler at mains for heat, burner runs for...

I have recently moved into a new home and replaced some of the radiators. A couple of them are larger double panels compared to what they originally were. In total, 3 large type 21's, 2 large type 22's and 2 small ones. It is a regular vented system with a cylinder and tank in loft. Now it...