Thanks for all the responses re my heating/boiler issue. Seems to be an issue with the thermostat not being sensitive enough - turning it down manually until it clicks off stops the burner and makes the boiler behave as it should, but the thermostat doesn't seem to be able to do this itself - it's like it never reaches the threshold temp (even though the room is warm enough acc to a thermometer).
Leaving it at the manually 'clicked off' temperature is too cold and there is too a big range between the click point depending which way you're turning the dial.
Thanks for all the responses re my heating/boiler issue. Seems to be an issue with the thermostat not being sensitive enough - turning it down manually until it clicks off stops the burner and makes the boiler behave as it should, but the thermostat doesn't seem to be able to do this itself - it's like it never reaches the threshold temp (even though the room is warm enough acc to a thermometer).
Leaving it at the manually 'clicked off' temperature is too cold and there is too a big range between the click point depending which way you're turning the dial.
Anyway, should be able to buy something digital for not much cash so will probably do that. Something like this I guess https://www.screwfix.com/p/danfoss-ret2000ms-digital-room-thermostat-230v-white/4644p (cue exploding boiler)