by ericmark »
Tue Jan 02, 2018 9:57 am
It is not the thermostat which will be at fault.
The independent thermostat and programmer are wired as pairs, in series with each other, however this is an old idea.
Today we use programmable thermostats so we can set different temperatures at different times of the day, it is far cheaper than having two thermostats and a programmer and gives better control, for hard wired looking at around £25.
Problem with the programmer is you need two thermostats, one for room temperature and one for anti frost. The latter will work as yours works now, So maybe you have connected to wrong terminals in the boiler?