How Do I Troubleshoot Mr. Heater Big Maxx?

If you are in need of a heater for your workplace, job site, or for recreational use, Mr. Heater makes a full line of kerosene, propane and natural gas portable heaters. These are lightweight, easily portable heaters that can be used almost anywhere. Enerco Group, Inc. makes and sells Mr. Heater and all the accessories you will ever need. The Mr. Heater Big Maxx is one of the more popular models they sell. If the heater ever needs repair, they are standing by to help, if your troubleshooting efforts do not work.

Step 1

Check to make sure that proper, sufficient gas is available to the heater. Make sure the cylinder is tightly attached and screwed straight onto the heater receptacle and that sufficient pressure is present. Review and be sure of the operating instructions, and the install, if completed, was done in accordance with the Mr. Heater process.

Step 2

Complete these checks, if the exhaust fan comes on briefly, then shuts off. Check all burners and verify they are lighting. Replace the burner limit sensor, if all burners are lighting, because the sensor is not detecting the flame.

Step 3

Check for exhaust venting next for too much back pressure, if the burners and sensors are not the problem. Review the install instructions for proper length of the exhaust venting. Look next for any vent blockage after checking for correct length within the install instructions.

Step 4

Test the combustion air pressure switch if the issue is not exhaust related. Join the red wire and the brown wire of the switch. See if the heater works; and if it does, replace the switch.

Step 5

Double check the gas supply if all else checks out fine. Make sure the gas supply is not shut off, and that gas is available to the heater.

Step 6

Use this check if the LED light is not on, indicating there is probably a wrong connection of the thermostat to the board. Check that the power supply is hooked up first, making sure there is 110V to the heater. If the obvious is not the problem, hook up a 24-volt rated thermostat to the R and W terminals. Check terminals C and R for 24 volts. Replace the transformer, if you do not measure 24 volts at terminals C and R. If both the terminals and the power supply are okay, replace the circuit board.

Step 7

Check and replace the blower and exhaust motors if they are running but there is no heat. This usually means that every limit sensor is activated. Replace the circuit board, if the blower and exhaust motors check out okay.