Vaillant VCW thermostat question?

[paddy69]

Hi!
I have finally got around to putting a thermostat on my system, a wireless Honeywell onto a Vaillant VCW 242.
I have just wired the actuator into the boiler using the same connections as the old Honeywell timer went into. The manual I have for the boiler shows connecting a Vaillant thermostat in to slightly different connections. Should I have wired the actuator into these???
Thanks!
Phil

 

[cross thread]

if it switches between 3 and 4 it will work

 

[paddy69]

Thanks, yes, that does work fine. I just wasn't sure if it should have been through 4 and 5!
The manual I have for the boiler shows a connection from 3 to a Randall time switch and connections from the Vaillant thermostat to 4 and 5! Mind you, the Vaillant thermostat is also connected to the time switch and I couldn't see how that all tied in to a Honeywell wireless??
Don't know why I didn't do this a long time ago.
Cheers!
Phil

 

[The831Bunny]

Hi

L & N to Honeywell

T3 on boiler to A on Honeywell
T4 on boiler to B on Honeywell

T5 is a Neutral that can be used rather than cramming two wires in the N terminal. If you wire across 4 to 5 it goes BANG

This is the same for ALL Vaillant combination boilers ever made.

An alternative I use is to supply the Honeywell receiver L from T3, link the other L to A, return from B to T4 on the boiler, N goes to T5. That way you only require three cores. External controls are killed when the main switch on the boiler is off.

Cheers Bunny