The most common domestic gas heater I deal with is possibly the Vulcan Quasar wall furnace. I also see a lot of Rinnai and Vulcan gas room heaters and various brands of decorative log fires, but the Vulcan Quasar wall furnace has become topical since the manufacturer has very decisively obsoleted the Quasar along with a number of other Vulcan heaters.

While it is now no longer possible to get OEM spares for the Quasar, it is still possible to get aftermarket spares from various Australian manufacturers. The three most common parts needing replacing are thermal fan switches, the fan motor, and the thermostat tube and bellows.

Common fault symptoms

unable to light pilot flame – this is usually repairable without needing parts
noisy fan – worn fan motor bearings
slow fan – faulty fan motor and or capacitor
fan running on – faulty thermal switch
fan not running at all – faulty fan and or thermal switch and or capacitor
unpredictable fan behaviour – faulty thermal switch
burner flame not throttling down no matter how hot room gets – broken thermostat tube and bellows
temperature dial refuses to stay still – broken thermostat tube and bellows
awful loud humming sound – faulty safety solenoid

vulcan qasar 40 gas heater


The Quasar gas heater was revised several times over the course of its impressive production life. The appliance shown here includes three thermal switches – one for overtemperature cut-out (all revisions had this), one to run the fan circuit, and another one to throttle the fan speed when boost mode is selected. This particular heater also has a “normally-closed” solenoid on the burner tube. The purpose of this solenoid is to disable the appliance from running the burner in the event of a power outage. Only the more recent units were fitted with this solenoid so if yours doesnt have it, your furnace is an older model than the one shown here.

vulcan qasar gas room heater

If you have a Quasar wall furnace, I can service it.

I also service Rinnai room heaters and other models of Vulcan room heaters, Canon, Masport, and other brands of decorative gas log fires.