Hi. My Potterton Suprima boiler stopped working- red light on constantly. I replaced the PCB with a new one. Then the boiler worked fine but no hot water. Heating working normally. S plan system. The water would only work if I put the 2 port valve on manually. So I changed the actuator - Danfoss HPA 2. Still same problem. Programmer set to constant, but actuator won’t come on automatically. Any suggestions please?