Advise needed on Pump overrun wiring please!
System is fully pumped S plan 3 zone with Honeywell Auto-bypass valve following are the specification.
Boiler: British Gas 330
Pump: Grundfos Pump
Valve: 3 into Honeywell 22mm 2Port valve: 1>Heating Downstairs. 2>Heating Upstairs. 3>Heating...