A gas guy cant work on this boiler, its kerosene fired.
Any of the wireless RF stats can be used, honeywell by far the most reliable.
simple fit, remove top cover over boiler 'stat, with mains OFF and remove the 'strap' link on the two room thermostat terminals. replace with a two-core wire leading to the rf stat sender unit. wire in to manufacturers diagram. an OFTEC engineer or qualified heating system electrician can do this for you.
mark properjob, February 2012