Replace old room thermostat with Honeywell t4 in a W-Plan system

[Rob404]

We have a really old heating system, its a W-plan with an ancient honeywell room stat (3 wired like in the schematic attached) and a honeywell st699 controller, I want to replace the room stat with ideally a honeywell T4 - is this possible? The wiring diagrams in the t4 don't seem to cover the W-plan diverting valve ?
Can anyone shed any light please? Many thanks

 

[jeff the gasman]

Just wire to terminals 1 and 3 and safely terminate the neutral.
Set controller to heating constant an hot water timed.

 

[Rob404]

Thanks Jeff, so am I right in saying
1 (from old stat) goes to A (on the new one)
and 3 goes to B?

 

[jeff the gasman]

Thanks Jeff, so am I right in saying
1 (from old stat) goes to A (on the new one)
and 3 goes to B?

Yes mate.

 

[Rob404]

Yes mate.

Thank you working perfectly