Mr. Heater Won’t Stay Lit: Causes and Solutions

When you’re out on the ice with the wind howling and the temperature dropping, the last thing you want is a malfunctioning heater.

Knowing how to restart your Mr. Heater heater on the ice can stop you from packing up early.

The popular Buddy Series heaters from Mr. Heater are typically dependable but can become glitchy when poorly maintained.

If your heater is shutting off or not lighting, read on to find causes and user-friendly solutions that can get you back on the ice or keep you out there.

What is a Mr. Heater?

If you’re new to ice fishing or in the market for your first ice fishing heater, there are a few things to look for. These include portability, fuel type, type of heater (forced air versus radiant heat), heat output, and safety.

The heaters best suited for use in a popup ice shelter are small, propane-fired, radiant heaters with oxygen sensors. Larger forced air units are great if you have an Ice Castle shelter.

Mr. Heater is the brand name of a popular heater maker. Their Buddy Series models are popular for ice fishing because of their portable size. They run on propane and have a high heat output, oxygen sensors, and a tip-over safety switch.

Various sizes are available, ranging from 3,800 BTUs to 11,000 BTUs. They run on a one-pound propane tank  or on a 20-pound tank with a connection adapter  and a braided hose  to maintain pressure.

Now that you know a little about these propane heaters, let’s take a look at some of the causes and solutions to your Mr. Heater shutting off or not lighting.

1. Poor Fitting Connection Losing Gas Pressure

• Mr. Heater’s heaters connect directly to 1-pound propane bottles and operate on 11 W.C. (water column), which is equivalent to 0.40 psi. Gas pressure below the 11 W.C. level can cause the heater to shut off or burn poorly.
• If the connecting hose is loose or doesn’t fit the heater’s standard C10 female thread connection properly, low gas pressure can occur when using a 20-pound propane tank to a Buddy series heater.

Solutions

• To check for leaks, put a few drops of dish soap and a quarter cup of water in a bottle and shake until foamy. Cover the connection with the suds. If there’s a leak, the bubbles will grow.
• Reconnect the hose at both ends, gently tighten, and retest for leaks.
• If leaks continue, purchase an adapter for 1-pound propane bottles  to get a better connection. You can also use Mr. Heater’s 10-inch Buddy Family hose assembly  for proper connections.

2. Inadequate Air Supply

Your Mr. Heater needs a vent of at least nine square inches at both ground level and the ceiling. Restricting air flow below the required minimums can cause your heater to shut off.

Solution

• Ensure the heater is placed in an open area free of clutter, and that air inlets and outlets of at least 3 x 3 inches are available at ground level and the top of your shelter.
• Clearances of 30 inches on the top and 6 inches on the sides, 24 inches in the front, and 0 inches in the rear are suggested.
• Mr. Heaters are rated as safe for indoor use with proper ventilation and have ODS oxygen depletion sensors and carbon monoxide detectors that will shut off the heater.
• Early signs of carbon monoxide poisoning include headache, dizziness, and nausea. If you experience these symptoms, get fresh air at once!
• Pregnant women, people with heart, lung disease, anemia, using alcohol or at high altitudes are affected more quickly by carbon monoxide.

3. Tip-Over Switch Activated

For safety purposes, your Buddy heater uses a tip-over switch that shuts off the gas. Your heater doesn’t need to fall over for the shut-off to work; tipping a specified number of degrees will shut down the heater.

Solutions

• If you have bumped your heater or tipped it accidentally, you need to ensure the heater is level, then restart it.
• To limit accidental shut-offs due to tipping, consider the clearances recommended above as minimum clearances for the safe operation of your heater.
• You can eliminate the problem by following the steps in this video to bypass the tip switch. Tampering with the tip switch will void any warranties due to negligence or abnormal wear. Ask yourself, is the added risk worth convenience?

4. Main Burner Blocked

The main burner can become clogged when used with a 20-pound tank and a regulator. Your heater has a built-in regulator, so an inline regulator isn’t needed. Using a regulator with a 20-pound tank creates high pressure that leaches out minute particles of oil and plasticizers that in time will foul the main burner.

Solutions

• The easiest fix is prevention. Using the standard one-pound gas bottles has the advantage of cleaner propane and a properly fitting connection.
• You can also use Mr. Heater’s hose assembly (#F273704) . The hose doesn’t have any plasticizers or oily contaminants to clog your burner and fits properly.
• Add an inline Mr. Heater F273699 Fuel Filter , then clean the burner.

• How to clean the main burner:
• Always allow the heater to cool before servicing.
• Shut off the gas and remove the gas bottle.
• Disconnect the hose from the heater.
• Remove the rear cover by loosening the four rear cover screws.
• Pull the cover out from the base to remove the top clips.
• Remove the burner assembly from the back of the unit by removing the four screws securing the burner.
• Check the heater housing for spider webs and dust accumulations and clean as needed. A small vacuum  or canned air  will help.

• Inspect the main burner orifice and venturi; if needed, clean with rubbing alcohol and a q-tip. Blow out and dry with canned air.
• Check the pilot for dust and spider webs. Use canned air (30 psi max.) to blow debris from the ceramic burner assembly and the venturi tube.
• Reverse the procedure to reassemble the heater, making sure the screws are snug and the fuel line is tight with no leaks.
• Check for gas leaks by applying soap suds to the connection; if the bubbles grow, there’s a leak. Remove the hose and reconnect, ensure the fitting isn’t cross-threaded, and recheck for leaks.

5. Pilot Light is Dirty

With normal use, dust and debris like spider webs can block up your heater’s pilot light, making lighting difficult or impossible. If the pilot continues to shut off when released after a minute, your pilot light needs cleaning, or the thermocouple needs replacing.

Solutions

Begin by checking the Pilot light assembly.

• Turn your heater’s control dial to pilot, depress and light the heater. If the flame is yellowish or red, the pilot needs cleaning.
• Make sure the heater is completely cooled.
• Remove the wire cover on the heater front.
• You’ll need a q-tip and isopropyl alcohol.
• Remove most cotton from the swab tip, dip it in alcohol and insert it into the pilot tube to clean. Inspect for cotton residue.
• Use canned air to dry and clean the pilot tube; insert a plastic extension tube into the line to dry.
• Recheck the pilot flame; if it is still yellow or red, replace the pilot light assembly .

6. Thermocouple is Malfunctioning

If your pilot light is burning with a proper bluish flame, but your heater still shuts off when the pilot button is released, you need to replace your thermocouple . The thermocouple is heated by the pilot light so it will open and allow gas to flow to the burner; if it doesn’t open, the heater shuts off.

Solution

For step-by-step instructions on replacing your heaters thermocouple, watch the video above. You also have the option of bypassing the thermocouple; this will get your heater working again but will void your warranty.

7. Clogged Fuel Filter

When you run your Buddy heater on a 20-pound propane tank, it’s recommended that you use a fuel filter to remove the contaminants in many hoses. You can avoid this by using Mr. Heater’s 10-foot propane hose #F273704 . It is manufactured without contaminants that may leach out.

Solution

• Shut off the heater and let it cool completely.
• Shut off the valve on the 20-pound tank.
• Disconnect the hose at the heater by unscrewing the fitting on the old fuel filter.
• Unscrew the fuel filter. For the best results, replace it with a new Mr. Heater fuel filter once a year.
• Screw in the new filter and reconnect the gas hose to the filter fitting.
• Open the valve on the tank and brush soap suds on the connection to recheck for leaks; if the bubbles grow, there’s a leak. Remove, reconnect, and retest.
• When you’re sure there are no leaks, you’re ready to start the heater.