I have replaced a mechanical thermostat with a Programmable Honeywell
CM907 to control a Vaillant TURBOmax Plus 828E Combi Boiler that runs
The problem is that when the thermostat switched to fire up the boiler,
the boiler does not fire up until about 5 minutes later.
This situation is actually listed in the troubleshooting guide for the
Heating switches ON or OFF too slowly or quickly
CM907 not set correctly for your system
I'm the installer and I'm stuck. Has anyone got any idea as how this
thing should be set up to remove the delay in starting the boiler?