Vaillant 824 control issue

[any-mgzt]

I have a Vaillant 824 that has had a new PCB fitted and programmed, my issue is that now the boiler will not control from the thermostat WiFi type, I have checked that the receiver is paired with the thermostat and it is. If I demand heating with the stat the receivers green light comes on.

The plumber who fitted the new PCB is claiming that it's my stat that's at fault and refusing to come back to rectify the issue I have. We can control the heating by increasing the water temp at the boiler but that's not ideal as it stays on all the time.

The timer / thermostat is a Honeywell 927 and was replaced around 12 months ago.

Anyone have any idea what the possible cause is.

[gas4you]

Is this a mk1 version?

The receiver should be wired into 3 & 4. Can you check this?

[any-mgzt]

@gas4you Many thanks for your reply. I looked today and yes the reciever was connected to pins 3 & 4 as was the link wire that should have been removed. It's now been removed and I have tidied up the connection with crimped terminations looks much neater and appears to be working fine now.