A gas heater service is only “done properly” when it’s treated as a safety-and-performance job, not a wipe-down. The right checks depend on heater type (ducted, wall furnace, space heater), flueing, ventilation, age, and how it’s been behaving (odour, soot, shutdowns, noisy fan, slow ignition). In the ACT, gas work must be performed by appropriately qualified people and meet the required standard of work under the Gas Safety Act 2000.