On the wiki the Y plan diagram shows the orange wire to the 3 port valve, w hich is described as having odd voltages on it at times, connected to the p ump & boiler. Surely this isn't right, it must be another wire that has the se fractional mains voltages on.
NT
If you look at the internals of the valve:
you can see how you may get odd voltages present. Note that the orange wire is not the only call for heat - it can also be derived from the cylinder stat.
Yes, I looked at that. I was just surprised by the pump being fed with wacky voltages when it should be off, but apparently that's how it works. Whether the overrun timer I've got will play ball with that I've no idea.
NT
Through 270K+ of resistance its only going to be able to sink 800uA odd. So the pump will pull it down to neutral in reality.
With pump connected I've measured, using an ac dmm: 74v & 150v. I don't act ually know if the pump is connected to the orange wire or not, or somewhere else, the wiring centre has so far proven near impossible to work with. I really need to find out, but it'll mean some dismantling.
NT
If it does not work then look for an old post of mine. I had a similar problem with a WB boiler that did not like the odd voltages. John Stumbles answered the question and Geoff supplied the part/snubber.
Basically it was a
ISTR that it is Viessemann that supply a snubber with their boilers if you are having problems with Y plans.
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