Can a lock be installed on a hot nouns furnace thermostat? My boarders keep turning the furnace stale, this may save on fuel...

My boarders keep turning the furnace stale, this may save on fuel however I am cold and do not want the furnace rotten in Nova Scotia winters.
Gas wet electric fire next to leave setting....
Answers:    Thermostat Guards
Protect your thermostat from tamper with a thermostat guard
http://www.prothermostats.com/category.p...
Snowblower Help!?
write a spanking new contract stating that boarders will be charged a fee respectively time the furnace is changed without written approval. You can buy a lockable cover for the thermostat.