VAILLANT VCW GB 242 hot water ok no heating

[charlotte25]

My combi boiler hot water works fine but the heating does not work at all. The water pressure is above 2 bars. there is no response from the boiler when i switch it to heating. would appreciate any advice thanks

 

[fixter1]

do you have a room stat/ clock ??????

 

[stevetheplumber]

when heating is switched on you should have power on terminals 3 and 4 this will check that external controls are calling for heat next check would be the threeway valve