Mr. Heater MH45T - User Manual

Questions and Answers

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Mary LeeJul 26, 2025
Why Mr. Heater MH45T Heater burners will not light?
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  Jeffery 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.
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Angela ElliottJul 31, 2025
What to do if my Mr. Heater MH45T Heater burner lights, turns red but will not stay lit?
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  Kimberly HallJul 31, 2025
  If your Mr. Heater Heater burner lights but won't stay lit, there are a few potential causes. Check that the thermocouple is securely fastened and positioned correctly, ideally with the tip 3/16” to 3/8” from the screen. If both are fine, the thermocouple or the safety shutoff may be defective and need replacement.
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Nicole GoodwinAug 5, 2025
What to do if I hear gas but Mr. Heater MH45T Heater burners will not light (hissing)?
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  Robert CalhounAug 5, 2025
  If you hear gas hissing but the burners on your Mr. Heater Heater won't light, it could be due to air in the propane tank, in which case you should return the tank to the dealer to purge the air. Alternatively, the regulator might be defective and require replacement, or the orifice could be partially plugged, needing cleaning or replacement.
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amy37Aug 10, 2025
How to fix a blue flame at top of Mr. Heater MH45T screen?
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  Anthony LivingstonAug 10, 2025
  A blue flame at the top of your Mr. Heater Heater screen can be caused by a couple of issues. If the heater has been in storage, clean all openings with high-pressure air. Alternatively, the regulator may be defective and require replacement.
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Jennifer FisherAug 15, 2025
Why my Mr. Heater MH45T has only blue flame – never gets red?
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  karenlopezAug 15, 2025
  If your Mr. Heater Heater only produces a blue flame and never turns red, it could be due to an obstruction in the venturi. Try cleaning the venturi tube with a wire. Another possibility is a partially plugged orifice; in this case, use high-pressure air to clean the venturi, orifice, and/or screens. It can also be the plugged screen. Disconnect heater from tank, reinstall heater, open tank valve slowly, light heater.
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Kelly NunezAug 20, 2025
What to do if connection at propane tank leaking gas after securing Mr. Heater MH45T?
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  Nicole ReedAug 20, 2025
  If you notice a gas leak at the propane tank connection after securing your Mr. Heater Heater, the “O-Ring” on the POL might be missing or defective, requiring replacement of the “O” ring or POL. It is also possible that the valve seat on the cylinder is worn, in that case return it to the dealer.