I have an old baxi boiler system n in January had to have the "pipe coupler/diverter"to the upstairs pump replaced. I had also replaced an old Honeywell thermostat with separate water/ch on/off switches for a new bog standard thermostat in that same week. Since then my boiler seems to ignore the room thermostat n only switches off when the boiler thermostat reaches its temp. I wondering if I have caused the problem or the engineer replacing the diverter has done something? I'm thinkin maybe it's something upstairss cos the eater doesn't seem to switch off til the boiler temp is met n is dangerously hot.... Any ideas anyone please
