When cylinder stat is calling for hot water the grey wire is 240v to neutral. When cylinder stat is satisfied it's approx 170v to neutral is this correct shouldn't it be zero volts?
white 240v c/h on.
orange 240v with any demand.
grey 240v h/w on
grey 50v - 200v h/w off or mid position... i think?
Ian
January 2010
mid position valves are a pain when it comes to fault finding. depending on the manufacturer the voltage can drop as low as 50v when hot water is satisfied.