Having fixed a problem with the Suprima 80 last year by getting a replacement boiler PCB, all was well until a few days ago when I switched off the CH at the programmer. What I noticed the next day was that the radictors were still heating up when the HW was on.
I suspected the Honeywell Y valve as I'd also had to repace the motor in the actuator head last year. The motor seemed fine, so suspected the microswitches. In the end, as I'd bought a spare V4073A Motorised Mid-Position Value last year just in case the replacement motor wasn't the answer, I decided to repace the entire actuator head with the one from the new spare. So I carefully removed each of the white, grey, orange, blue and yellow/green wires from the junction box, replacing each with the appropriate wire from the new actuator head and thought all would be well....
The boiler LED is on constant orange and the boiler instructions fault finding says to check for SwL (call for heat). The programmer has CH on, and the room thermostat is up, but the SwL on the boiler is not live. Yet the white wire on the V4073A is live, as is the orange and the grey.
It seems the boiler just is not getting a call for heat.
Any suggestions? It could be that the new style (all enclosed) PCB in the boiler is faulty, or it could be that the new V4073A actuator head microswitches are faulty? The motor works, and I can see/hear that when the room thermostat is turned up, the V4073A responds.
At present, there is no heat and no hot water.