Recent content by jamesmccosh

Thanks. However, in order to avoid the circuit tracing I eventually had to do, I replaced first the programmer and then the motorised valve - both unnecessary. Still, the approximately £100 outlay is cheaper than a visit from an engineer and I've now given the system a new lease of life and I...

My problem was that the orange wire is near mains voltage when either white or grey is at mains and the valve is fully open. It turns out that in this state the orange wire is always connected either to the white or the grey, if not directly, then via 280K ohms. This means that, unless current...

these readings are right so I would say your new valve is faulty, was it a complete valve or just the powerhead? I bought a complete valve but just replaced the head. Referring to the diagram in www.gasheating.co.uk/mid-position-valve.html What value are the resistors R1 and R2? If...

0v to white, 240V to grey. The valve is brand new, fitted today.

In the state I described above, there's 230 volts on the orange and 39 volts on the terminal it was connected to.

Hang on I'll go and try.

My Micron 80FF is controlled by a Horstmann H27 programmer and a Honeywell 3 port valve. The valve orange wire is connected to the LS on the boiler. When heat is required this carries the full 240 volts to indicate that the boiler should fire up. However, if the valve is fully towards A...