Mr Heater Big Maxx 2 Flashes [5 Easy Solutions]

Getting Mr Heater Big Maxx 2 flashes message means that your heater can’t detect a flame or the flame won’t stay lit. The possible causes behind this error message are dirty or broken flame sensor, dirty or bad pilot, malfunctioning thermocouple, an air leak in the gas line, and insufficient gas supply.

There’s no need to get anxious. Just read our guide for  Mr heater’s big Maxx 2 flashes and fix your heater ASAP!

Mr Heater Big Maxx 2 Flashes [5 Easy Solutions]

In this section, we’ll take an in-depth look into the causes and explore their simple solutions. 

1. Dirty or Broken Flame Sensor

The flame sensor detects the pilot flame before opening up the gas valves to light up the main burners. It is a safety mechanism that ensures there’s no leaked gas. Check the pilot light. If it is lit and you’re still getting the error message, you most likely have an issue with the flame sensor.


Take out the flame sensor and inspect it. In case, it is dirty, clean it properly. A broken or cracked flame sensor needs to be replaced with a new one. Don’t try to bypass the flame sensor. It is dangerous. You don’t want to burn your house down over a few bucks.

2. Dirty or Bad Pilot Assembly

In case, the pilot flame isn’t strong or won’t stay lit, you may have a problem with your pilot assembly. 


Take out your pilot assembly and clean it if needed. Check out this video to learn exactly how to go about cleaning your pilot. After proper cleaning, if the error message persists, your pilot assembly may need a replacement.

3. Malfunctioning Thermocouple

A bad thermocouple is a common issue that causes pilot light to become unsteady or not light at all. To be sure that the thermocouple is the culprit, you can test it with a multimeter. Your thermocouple is broken if the reading on the meter does not indicate 12mV or above.


The only way to deal with a broken thermocouple is to get it replaces. You may need to enlist the help of a professional. But in case you have some technical knowledge, follow the video below to get your heater sorted.

4. Air Leak In Gas Line

The pilot will not ignite properly if there is air in the gas line. 


You’ll need to bleed the air out of your gas line to get your heater up and running again. 

5. Insufficient Gas Supply

Your heater runs on gas. So, if there is an adequate fuel supply, your pilot won’t stay lit. No gas, low gas pressure or, dirt in the gas line can be what’s wrong with your gas supply.


A quick call to your gas utility company to get them to look into your issue is a good idea. They’ll be able to help you out.


Why is my garage heater beeping?

When the air filter needs to be replaced, some furnaces will beep. Always check your owner’s manual to see what a beeping sound on your heating system indicates.

How do you reset a Hot Dawg heater?

shut down the power supply to the control for more than 1 second or remove the thermostat call for heat for more than 1 but less than 20 seconds to manually reset the lockout.

What is a dump switch?

On propane heaters, a dump switch is a safety feature that turns off the gas if the heater is knocked over.


Hopefully, now you know how to get rid of the double flash error message. You can read our troubleshooting guide on all the common heater issues faced by Mr. Heater users.

In case you have any questions, leave a comment below. We will get back to you soon. 

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