20 Most Recent Mr. Heater Natural Gas Garage Heater - 45,000 BTU Questions & Answers

The capacitor in that unit is for starting the motor that drives the blower fan. It has no impact on the ignition of the gas burner. On the control board, there is a light that should be flashing, can you tell us how many times it is flashing?

3 amp is this not too small ??

Short circuited component/s at its internal circuit board. http://electronicshelponline.blogspot.com/

no gas supply

Check the flame sensor is clean . Also check out the pressure switch . Check out the snap disk high and low temp .

I would check out the flame sensor it needs cleaning

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).

If the fan does not run that causes the unit to over heat that in turn shuts every thing down.Check and see if the motor is not burnt out.

The infrared heat/light sensor is either faulty or covered up (soot?)

Take side cover off and you will see a little and your igniter should be in there

sounds like its not getting gas fast enough to keep burning,that happen to me and the gas line was to long of a run for enough gas keep coming. so I up the pipe runs real good the flame keeps burning, so you know you can only go 25 ft in half inch pipe then u lose your flame

Look for a flame sensor located in the flame of one of the burners. It will look like a small rod or probe and will have only 1 wire going to it from circuit board. Polish it with a scrub pad or stiff wire brush. Check the wire for a good connection as well as any ground wires off of the circuit board.

check your limit switch

I am only guessing since you have not given very much information. I would check to see if you have the power phased right. Some boards are polarity sensitive. Which means that the common should not have voltage to ground. Check and make sure L1 has 120 volts to ground and common. and that you have 0 volts from common to ground..