Central heating thermostat

I couldn’t say for sure but it looks like you need a new programmer that has wireless thermostat. There may be some sort of thermostat that can be fitted in parallel which could override the current programmes but I am not sure how manufacturers would look upon that. If you were to get a thermostat it would just have the heating on for longer not any hotter. You may be able to get the desired temperatures by increasing/decreasing the set water temperature in the radiators or increasing/ decreasing the amount of time they are set to be hot for. Addition Have just been told you can use the Honeywell T6360B, they also have a Honeywell Home version that is similar to hive.

Yes with the st9400 models you can add a thermostat and to be honest you should have one to comply with the current regulations. Thai can prove problematic as it’ll need wiring in or a at least a wire to a rf receiver unit. Your next option and most efficient way of controlling the system is to fit a hive unit. It will replace the programmer directly so no wiring will need to be changed. The wireless thermostat give far more control and options as well.