Question about Mr. Heater MH125KT Utility

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I have a Mr. Heater 125,000 BTU contractor series shop heater and it started surging spurts of flame rather than run smoothly.

Checked valves, fuel level, turned off and on, called Mr. Heater (put on terminal hold).

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You may have contaminants in the fuel, such as water. Fuel that sits in gas cans can sometimes have condensed water in it. There may also be something that has clogged teh fuel flow.

Posted on Nov 26, 2014


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Posted on Jan 02, 2017

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SOURCE: mr heater 75,000 btu kerosene heater

I got this error when I had increased my air pressure to 5.5 lbs. Cut the pressure back to 4.5 and it has been running fine for the last three hours. At 5.5 it got WARM ... solid red hot cone and flames coming around the outside. Had been having problems with it cutting off for no apparent reason in really cold weather. Took the pump apart and cleaned it and checked for clearances and reassembled but it did not help much. Will schedule it for a total pump replacement with new filters asap. Pump parts and filter are not that bad. Should come in under $50.00
Hope this helps
I also turned the thermostat back a little off of full on.

Posted on Feb 04, 2009

  • 1902 Answers

SOURCE: propane convection heater won't maintain full flame

Seems like the valve is not opening up fully or the adjustment is out of adjustment. Try adjusting the flame.

Posted on Feb 15, 2009

  • 986 Answers

SOURCE: pilot will not stay on

replace your regulater,which almost cost as much a a new heater.I have own 4 or 5 and finally got a good one,I have in the past cleaned out the regulator that was plugged with oil from the propane,they put oil in the propane for leak detection,I hope this helps you

Posted on Dec 02, 2009

Testimonial: "Thank You. perhaps it is not adjusted properly. I so appreciate the quick response..Good Job!!!"

  • 1 Answer

SOURCE: Mr. Heater Natural Gas Garage Heater - 45,000 BTU.

my garage heater was working early this winter. I turned the thermostat to 0, but when I went to restart heater nothing happens, can you help me with this problem?

Posted on Dec 27, 2009

  • 1420 Answers

SOURCE: Mr. Heater Big Maxx 75,000 BTU Heater will not

Is the circuit board giving you a blinking error code?
On a call for heat, the 24 volt thermostat sends a signal to the control module. The control module will indicate a call for heat with a light on the control either blinking or remain solid depending upon model. The inducer (exhaust) blower will purge all gasses from the furnace and pressurize a pressure switch. Once the pressure switch tells the module to continue, the electronic ignition will energize and send 120 volts to the igniter. The igniter will glow and you will be able to see it if viewed thru the small inspection port. Once the igniter gets hot enough, it sends a signal to the module opening up the gas valve (24 volts). Either a pilot will come on or the burner tube will ignite then spread the flame to all burners. Lastly a safety sensor will be looking for a certain temperature within a few seconds and the furnace will continue to operate and the room air blower will turn on in a minute or two.

What could go wrong? The unit will not run if there is no signal from the thermostat (bad thermostat or broken wire), the control module does not sense a signal from the thermostat (bad control), the inducer does not energize (bad motor), the pressure switch does not close (blocked vent piping, bad switch, plugged condensate hose), the igniter does not energize (bad control, bad igniter), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not light (dirty pilot), the burner does not light (bad burner, plugged orifice, not enough combustion air), the flame does not spread to each burner (bad flame spreader, dirty flame spreader, more bad burners), the flame safety sensor does not detect flame (dirty or bad flame spreader, bad flame sensor, broken wire, bad control), or the room air blower does not energize (bad fan motor, bad control).

Posted on Feb 26, 2010

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