Hi,
I've recently moved in to a new house and am having difficulty with the thermostat.
I have a Honeywell ST9100C, it is set to run and the stat is calling for heat - but this won't fire the boiler, the only way to get CH on the boiler to run is to switch the boiler from timed to continuous, but then it is only controlled by the thermostat on the boiler, not the external one.
I have found a wiring problem with the ST9100C - the mains earth cable had been wired to terminal 1 on the back plate, rendering the entire boiler without an earth connection.
Terminal 4 on the stat is wired to 19 on the boiler (CH Timed on)
I'd appreciate any help, thanks!
I've recently moved in to a new house and am having difficulty with the thermostat.
I have a Honeywell ST9100C, it is set to run and the stat is calling for heat - but this won't fire the boiler, the only way to get CH on the boiler to run is to switch the boiler from timed to continuous, but then it is only controlled by the thermostat on the boiler, not the external one.
I have found a wiring problem with the ST9100C - the mains earth cable had been wired to terminal 1 on the back plate, rendering the entire boiler without an earth connection.
Terminal 4 on the stat is wired to 19 on the boiler (CH Timed on)
I'd appreciate any help, thanks!