our Pot suprima 50 boiler wouldn`t heat CH at the weekend, but HW was ok. thermostat would call boiler but boiler would not respond. manually switched over 3-way valve & managed `til monday. becuse the PCB went 4-5 yrs ago got a new replacement. instead of PCB, a Siemans "PLC" box is the preferred method now. replaced , but now 3-way doesn`t seem to work. Could I have either broken the motor on 3-way (awkward location, removal to inspect) or could there be a wiring problem?
grateful for advice.
grateful for advice.
