S StevieBs New member Joined Aug 9, 2021 Messages 1 Reaction score 0 Aug 9, 2021 #1 I have just installed a Vaillant Ecotec OV430 system boiler and need to wire the boiler using the old Y plan wiring. The question is what changes are required . Do I connect the orange wire from the 3 port valve to the boiler terminal RT?
I have just installed a Vaillant Ecotec OV430 system boiler and need to wire the boiler using the old Y plan wiring. The question is what changes are required . Do I connect the orange wire from the 3 port valve to the boiler terminal RT?