Most efficient use of boiler?

r0nanf

I have a wood pellet boiler, currently operated with just a timeclock - I understand that this is inefficient but I'm only getting around to a thermostat now as the house has been in continual renovation for two years. Currently the timeclock controls the temperature in the house, with blocks of two hours on/one hour off in the evening (provided its not completely baltic). We are about to install a solid fuel stove (which will be the primary heat source downstairs) in the living room, and I am going to put a wireless thermostat upstairs in the main bedroom.

Is the ideal system to just have the boiler come on and stay on for the whole evening (4:30-11:30) with the wireless thermostat regulating the temperature via the circulation pump? I don't want too much heat upstairs so is having the boiler on solid for 7hrs just a waste of fuel seeing as the stat will keep the temperature at only 18C-ish? The other option is to have the stat control the boiler but I'd be concerned that frequent stopping/starting would knacker the machine.

Thanks in advance for your opinions!