Central heating wiring
- Thread starter derek.d
- Start date
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ChrisR
Many thanks for your reply, It appears from the Vaillant instructions that the pump connections are provided on the boiler connection block also a permanetnt live is requied, all switching is done via a Sw/live connection on the connection block,it appears that a live feed is taken through a programmer then through the room stat to the connection block, any suggestions how to connect the two stats with the two motorised valves
Many thanks for your reply, It appears from the Vaillant instructions that the pump connections are provided on the boiler connection block also a permanetnt live is requied, all switching is done via a Sw/live connection on the connection block,it appears that a live feed is taken through a programmer then through the room stat to the connection block, any suggestions how to connect the two stats with the two motorised valves
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A Vaillant ecoMAX 18E with an external pump? I have never seen one of these, but you learn something new everyday? I have seen them with a second pump on the optional PCB extender but you would not be likely to need this on a puny 18kw boiler.
If it has an internal pump, then the wiring is typical Vaillant which differs from most other boilers in one way.
You must wire in the boiler only to a permanent live connection, eg: fused spur with L,N,E to the dedicated mains block in the boiler.
Then you wire the live connection from Vaillant terminal number 3 to the outboard programmer permanent clock live. Thereafter it is as per Honeywell specs.
The orange wire(s) from the valve(s) then are directed to boiler terminal 4.
Terminal 5 is a spare neutral connection (and a new runway at Hrow).
If you do not supply the programmer from pin 3 the boiler cannot be turned off from it's mains switch.
If it has an internal pump, then the wiring is typical Vaillant which differs from most other boilers in one way.
You must wire in the boiler only to a permanent live connection, eg: fused spur with L,N,E to the dedicated mains block in the boiler.
Then you wire the live connection from Vaillant terminal number 3 to the outboard programmer permanent clock live. Thereafter it is as per Honeywell specs.
The orange wire(s) from the valve(s) then are directed to boiler terminal 4.
Terminal 5 is a spare neutral connection (and a new runway at Hrow).
If you do not supply the programmer from pin 3 the boiler cannot be turned off from it's mains switch.
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