Mr Heater Troubleshooting

Mr Heater Troubleshooting Guide: Fixes for Common Problems

Getting a Mr Heater for your garage, house, or golf cart is necessary, as the cold season is upon us. However, since we know that no gadget is without its very peculiar problems, you must equip yourself with the necessary info for Mr Heater troubleshooting.

In this article, I have created a Mr Heater troubleshooting guide to help you identify its various problems and how to fix them.

Mr Heater Troubleshooting Guide

Mr Heater Troubleshooting

In the following Mr. Heater troubleshooting guide sections, we’ll go over some of its common problems and provide solutions for troubleshooting and fixing them.

Mr. Heater Flame Problem

Below are some Mr. Heater flame problems you can experience and how to fix them:

1. Heater Flaming Up

This is often a result of improper air and gas mixture, high incoming gas pressure, faulty gas regulator, and clogged burner.

How to Fix

  1. Adjust the heater flame.
  2. If this doesn’t change, clean the air tube and clog the burner.
  3. You should contact an expert if you are not experienced enough, as dealing with gas can be dangerous.
  4. Ensure the proper mix of gas and air in the heater.
  5. Ensure the gas pressure is not very high.
  6. If the above doesn’t work, inspect and replace the faulty regulator.

2. Flame Keeps Going Out

This can result from a faulty pilot assembly, disconnected tip switch wires, or an empty fuel tank.

How to Fix

  1. Check and ensure your heater is getting enough fuel
  2. Depress the heater’s control knob completely in the pilot’s position.
  3. Clean the pilot and ensure the flames surround the thermocouple.
  4. Check and replace any malfunctioning pilot assembly.
  5. Ensure the tip switch wires are properly connected.

3. Incorrect Flame Pattern

The excess distance between the flame and the thermocouple, low fuel supply, clogged air hole inlet, and improper gas pressure usually causes this.

How to Fix

  1. Ensure the heater’s flame is touching the thermocouple.
  2. Place the thermocouple close to the flame.
  3. Ensure the gas tank is properly filled
  4. Clean out the air inlet.

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Mr Heater Big Buddy Troubleshooting

Below are some common Mr heater big buddy issues and how to troubleshoot them:

1. Heater Making whistling Noise

This is often a result of blocked air passageways, the air in gas lines, and clogged burner orifices.

How to Fix

  1. If there’s air in the gas line, let the heater keep running until all the air is released out of the system. Have your gas line checked for any more air left.
  2. Place the heater in the coldest section of the room.
  3. Clean up the burner orifice. If this issue persists, replace the burner orifice.

2. Heater Keeps Shutting Off

This is often caused by inadequate fresh air to burn, a faulty regulator, or a clogged pilot.

How to Fix

  1. Clean up the pilot.
  2. Ensure the heater is getting adequate combustible air.
  3. Replace the regulator if it is faulty.

3. Mr Heater Big Buddy Doesn’t Ignite Due to a Lack of Spark

This is usually a result of a damaged spark electrode, faulty ignition wire, or piezo igniter.

How to Fix

  1. If your spark electrode is malfunctioning, replace the oxygen depletion sensor of your heater.
  2. Ensure the ignition wire is properly connected to the spark electrode and the ground wire is connected to the frame.
  3. Check for signs of damage on the ignition wire and remove it.
  4. If the above doesn’t work, replace the igniter.

4. Pilot Won’t Light

A lack of gas in the heater, malfunctioning pilot assembly, and obstruction of the pilot by foreign objects usually cause this.

How to Fix

  1. Check the fuel tank and ensure there’s enough propane.
  2. Check if the fuel hose is clogged. 
  3. If everything is okay, ensure the pilot assembly is clean. To do this, turn off the fuel supply and remove the pilot from the gas control mode. Blow compressed air into the pilot tube and use a pin to clean out any soot on the pilot. Wipe the assembly with a clean, dry cloth.
  4. Restart the heater. If the pilot doesn’t light, replace the pilot assembly.

Mr Heater Regulator Problems

Some issues that can result from a faulty Mr Heater regulator include:

  • No gas flow even when the gas is on
  • Heater is not staying lit.

Unfortunately, when issues occur in your Mr Heater due to a faulty regulator, replacing it is the only way to fix it.

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Mr Heater Troubleshooting Thermocouple

A faulty thermocouple can cause issues like limiting gas flow to the pilot tube and the heater not staying lit. To troubleshoot your thermocouple, do the following:

  1. Clean it up. To do this, you can remove the thermocouple from the process assembly using an emery cloth, lightly cleaning the tip. 
  2. However, cleaning is not a fix for thermocouple-related issues like inaccurate readings. In such cases, you must replace the thermocouple or bypass it. 
  3. To bypass a thermocouple, you must disconnect one of the ends from its source, which could be the end connected to the main gas control valve or the protruding directly into the pilot’s light.

Mr Heater Ignition Problems

Below are some common Mr Heater ignition problems and how to fix them:

1. The Igniter Very Often Does Not Cycle Long Enough to Light the Gas.

This can occur due to a cold gas valve or regulator, giving you low gas pressure, causing the unit not to light off, and lockout on flame failure. It can also result from loose ground connections on the control board.

How to Fix

  1. Check the gas pressure using a manometer.
  2. Check for loose ground connection on the control board and fix it.
  3. Clean out the connections on the control board.
  4. Try heating the gas valve and board a little with a heat gun ( take safety precautions when doing this)
  5. If the above doesn’t work, you must change the control board.

2. Delayed Ignition

This is caused either by low pressure in the manifold or a clogged burner orifice.

How to Fix

  1. Contact your gas utility company. 
  2. Clean or replace your heater’s burner orifice.

Mr Heater Troubleshooting won’t Stay Lit

This is usually a result of the following:

1. Faulty Thermocouple

  1. Readjust the thermocouple. 
  2. If this doesn’t work, replace it.

2. Faulty Pilot Light

  1. Clean the pilot light if it’s dirty.
  2. Ensure it is in a position where there is sufficient airflow.

3. Malfunctioning Sensors

  1. Use sandpaper to clean out dust from the sensors.
  2. Ensure that at least half of the sensor is covered by the flame.

4. Dirty Pilot Tube

  1. Turn off the gas.
  2. Unscrew the pilot tube from the heater and try cleaning it.
  3. You can blow compressed air into the tube to clean out the debris or use any pointy or sharp objects to remove dirt from the tube.
  4. Put the heater back together and turn the gas back on.
  5. You might have to replace the pilot tube if you can’t get the debris out.

5. Clogged Or Faulty Glass Valve

  1. Locate the glass valve around the burner and clean it. 
  2. Replace the glass valve with a new one if you cannot clean it.

Mr Heater Big Maxx Troubleshooting 2 Flashes

2 flashes on the Mr Heater Big Maxx show that the system is on lockout or has failed to detect or sustain a flame.

How to Fix

  1. check flame sensor is clean.
  2. Ensure the connections are tight and clean the ignitor.
  3. If this doesn’t work, jump out the pressure switch to see if it lights.

Mr Heater Big Maxx Troubleshooting 3 Flashes

3 flashes on your Mr Heater Big Maxx are usually a result of a pressure switch failure caused by a blockage at the fan end of the pressure tube.

How to Fix

  1. Remove the tube off the fan side nipple.
  2. Run a thin drill bit through the nipple to clear it out.
  3. Put the tube back on.
  4. If this does work, ensure the combustion fan comes on.
  5. There’s no obstruction to airflow in the combustion chamber.
  6. Check the tube between the induction smoke and pressure switch is properly connected and has no obstruction.
  7. Replace the pressure switch.

Mr Heater Propane Heater Troubleshooting

Mr Heater Propane Heater Troubleshooting

Below are some common issues with Mr Heater propane heater and how to troubleshoot them:

1. Mr Heater Propane Heater Keeps Shutting Off

This usually occurs when the thermocouple is far from the flame.

How to Fix

  1. Move the thermocouple closer to the flame.
  2. If this doesn’t work, check if the thermocouple is worn out and replace it.

2. Mr Heater Propane Heater Sparks but Does Not Light

This usually occurs when the gas cylinder is empty or shut off

How to Fix

  1. Check to know if the gas cylinder is empty and fill it.
  2. If the issue persists, carefully clean the gas valve using a needle.

3. Pilot Flickering Small Orange or Yellow-Colored Lights Instead of Blue.

How to Fix

  1. Clean out the pilot tube by turning off the gas first and gently poking a needle into the top of the pilot tube.

Mr Heater Contractor Series 125 000 Btu Troubleshooting

Below are some common issues with the Mr heater contractor series 125000 BTU and how to troubleshoot them:

1. Mr Heater Contractor Won’t Start

  1. Check out the electric eye for any fault and replace it if it is faulty.
  2. If it’s not faulty, make sure to clean out all dirt.
  3. Check the pressure sensors for any faults and replace them if necessary.

2. Mr Heater Contractor Won’t Stay Lit

  1. Add new fuel lines

3. Mr Heater Contractor Fires Like It Should, Runs for A Short Time, and Shuts Off

  1. Replace the high-limit switch

Mr Heater Garage Heater Troubleshooting

Below are common issues with Mr Heater garage heater and how to troubleshoot them:

1. Burning Smell from The Heater

A burning smell from your Mr heater garage heater is likely a result of dirt and dust burning in the heater.

How to Fix

  1. Unplug the heater.
  2. Wipe and clean off all the dirt and dust piled on it and plug it back. 

2. Can’t Change Temperature Settings on Mr Heater

This is usually a result of a faulty thermostat

How to Fix

  1. Replace it 

3. Heater Turns on And Off on Its Own

This usually happens when the furnace air passage is blocked.

How to Fix

  1. Remove every obstruction in front of the furnace passage.

4. Heater Not Producing Heat Even when The Fan Is Running

This is usually because of loose wiring in the heater’s system

How to Fix

  1. Unplug the heater
  2. Locate loose wiring and fix it.

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Mr Heater Forced Air Propane Heater Troubleshooting

Below are some common issues with Mr Heater’s forced air propane heater and how to troubleshoot them:

1. Motor Starts, but No Heat Comes Out

  • Check to see that your propane supply tank is turned on. 
  • Listen for the sound of the spark igniter, and it should make a fast ticking sound. 
  • If it doesn’t replace the igniter.

2. Heater Runs for A Few Minutes and Shuts Off

  • Ensure you have the right-sized tank for the air-forced propane heater you are using (for every 50,000 Btu output, you need at least a 20 to 40-pound LP tank). 
  • In below-freezing weather, ensure you have double the size of your propane source to maintain a sufficient flow volume for proper heater operation.

3. Heater Starts Giving Off a Bad Smell

  1. Try the heater in a different area where no chemicals are used
  2. If the smell goes away, try a different propane tank.

4. Heater Doesn’t Spark

  1. Clean the igniter with steel wool and readjust it, ensuring it is ¼ inches away from the orifice assembly. 
  2. If this does not fix the issue, ensure power goes to the assembly. 
  3. If it is, then the igniter or the board is bad. 
  4. Contact Technical Service to help.

Mr Heater MH30T Troubleshooting

Below are some common Mr Heater Mh30t issues and how to troubleshoot them:

1. The Burner Doesn’t Light Up

  1. Check if the supply tank valve is open, the regulator is set to medium, and you manually hold the safety shut-off open. If you do this and still don’t smell gas, replace the regular.

2. The Burner Doesn’t Stay Lit After the Release of The Safety Control Valve

  1. Disconnect the tip switch wires.
  2. Reconnect the two wires with a jumper wire or paper clip.
  3. If the heater works, replace the tip switch. If it doesn’t, change the thermocouple.

3. Blue Flame at The Top of The Heater

  1. Clean the unit using the maintenance manual guide. Check for spiders and dust build-ups on the back of the plenum tube.

4. The Heater Makes a Roar and Pop Sound, and The Rear Glows Red

  1. Block the heater from direct wind flow
  2. Clean out the riser tube with a pipe cleaner and low-pressure air.
  3. If this doesn’t work, replace the burner assembly.

5. The Heater Makes a High Pitch Sound

  1. Allow the heater to warm up.

How Do I Reset My Mr. Heater?

To reset your Mr Heater, follow these steps:

  1. Turn off the heater and disconnect the power source and gas supply, do not turn the pilot gas supply line off.
  2. Lower the thermostat temperature setting as low as possible.
  3. Hold a lit match to the pilot flame jet opening to relight the pilot light.
  4. Turn the circuit breaker on again and turn on the gas supply.
  5. Press and hold the reset button for about 30 seconds and increase the thermostat temperature.
  6. If it is an electric heater, turn off the power at the circuit breaker box, then press the reset button.

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What Causes Mr. Heater to Shut Off?

Your Mr Heater can shut off if there’s an issue with the sensor, clogged-up debris, the thermocouple is too far from the pilot flame, which can cause the gas supply to be interrupted, or a faulty propane heater gas line. Any one of these can cause defective heater flames triggering Mr Heater to shut off.

Why Does My Mr. Heater Propane Heater Keep Going Out?

When this happens, it is usually because your propane heater is detecting that the flame is faulty in some way which triggers the propane heater’s safety function causing it to keep going out. This either be a general defect or an issue with the heater’s sensor.

How Long Do Mr Heaters Last?

Mr Heater’s propane heater for golf carts can last for 7 hours, emitting an energy of about 3,000 BTUs on one 16 oz propane fuel, which is enough for almost 2 rounds of a golf game.


This winter period, knowing how to fix some common issues with your Mr Heater will save you a lot of hassle. I recommend you kindly follow this Mr Heater troubleshooting guide and the instructions. Ensure that when troubleshooting your heater, you take all necessary safety precautions. If you are not very experienced, you should contact an expert to help you with your Heater problems.

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