Y-plan hot water but no heating

[ianmcd]

Again mate, not dealt with many of these, so am I wrong in thinking that the lever moves to the sections labelled or is that for piping purposes only?

the lever locks the valve in mid position for filling purposes

 

[ericmark]

Sorry having a senior moment grey is powered to make valve go all the way, I got it wrong way around, so need to put grey to line and test, not disconnect it.

 

[jondub]

Thanks everyone for your help,

In semi-desperation I bought another valve head, this time a genuine Honeywell one, and hey presto all is well, heating is back on.
I'm not 100% sure what was wrong with the Corgi replacement, it certainly looks the same as the original.

John