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Mary LeeJul 26, 2025
Why Mr. Heater MH45T Heater burners will not light?
- JJeffery RoseJul 26, 2025
Several factors can prevent your Mr. Heater Heater burners from lighting. First, ensure the propane tank valve is open and the tank isn't empty. Check that the heater regulator is turned to the medium position and the Safety Shutoff plunger is depressed while lighting. Air in the manifold, hose, or propane tank can also be a cause; in this case, purge the air from the unit. Finally, if the excess flow valve in the POL fitting has activated, disconnect the heater from the tank, reinstall it, open the tank valve slowly, and then try lighting the heater.