Propane Heater Not Working? 5 Essential checks

The most common reasons for your propane heater not working are: a dirty thermocouple, a thermocouple that is too far from the flame, a blocked pilot tube, an empty/overfilled gas canister, and drafts. Fortunately, the majority of homeowners will be able to take care of these issues on their own. 

Below you will find easy-to-follow instructions. In the majority of cases, these steps will get your unit working in no time.

Why Is My Propane Heater Not Working? 5 Common Reasons

A propane heater is a relatively simple device and there are not that many things that can go wrong.

If you feel comfortable working with appliances and have a basic understanding of how a heater works, you’ll be able to fix your unit extremely fast.

If none of the tips mentioned below has helped, then make sure to invite a professional who is going to take care of the problem. 

Read: Why Gas Furnace Is Overheating?

The Thermocouple Is Too Far from the Flame

Your propane heater’s thermocouple is a safety device that is able to detect whether the pilot light is lit or not.

This component has a metal rod that is located close to the flame. The rod is also connected to the gas valve.

In a nutshell, a lit pilot light produces heat that sends a voltage through the thermocouple – this keeps the gas valve open (yes, thermocouples generate electricity directly from heat). However, if the metal rod fails to sense the flame, the gas line to the heater will be closed.

As a result, your propane heater won’t be working.

If the thermocouple is too far away from the pilot light, your unit won’t be getting any gas. So, you have to make sure that the component stays close to the pilot light.

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Tip: How do you know if the thermocouple is too far from the flame? Find the sensor on the thermocouple – it should be 2/3 into the flame.

thermocouple, pilot light, spark ignitor

At one point, you might have to bend the thermocouple. Follow the manufacturer’s instructions when doing that.

Here are a few tips that you should bear in mind:

  • Be extremely careful, when bending the thermocouple with your hands.
  • Avoid bends that go beyond 90 degrees.
  • Do not repeatedly bend the thermocouple back and forth – this may cause the stainless steel to break.

Fact: thermocouples are not designed to last as long as your heater. Usually, this component would need to be replaced every 1-2 years. 

Read: No Hot Water In The House? Here’s Why

The Thermocouple Is Dirty

A thermocouple is an element that is constantly being exposed to a hot flame. Of course, throughout time, soot will start to build up on this component.

Unfortunately, even a slight buildup can cause the thermocouple to malfunction – the flame sensor simply won’t be able to detect the flame. Rust and debris can also become a problem.

Propane heater not working: thermocouple rust

But the great news is that it’s relatively easy to fix this issue. You can manually clean the thermocouple.

  • Turn your heater off and shut off the gas valve. Leave the unit like that for at least a few minutes.
  • You’ll usually find the thermocouple in the gas control assembly – one end of this element will be sitting in the flame, while the other is on the electromagnetic valve.

Tip: before removing the thermocouple, you can take a photo of the way everything is assembled inside the unit (just in case).

  • You are going to need either a wrench or a screwdriver to detach the thermocouple from the pilot assembly.
  • Use emery cloth, sandpaper, or lint-free cloth to gently remove any debris, rust, and soot.

Warning! Do not touch the sensor on the thermocouple with bare hands – the oils on your fingers can make it less sensitive.

Also, do not use cleaning products on the thermocouple or pilot light as chemicals can be flammable.

  • Reattach the thermocouple between the pilot light and the gas valve.

Ensure that there was no fluff, hairs, or any other loose material on the cloth as all these things will cause sparks to fly in the heater.

The Pilot Tube Is Blocked

In your heater, propane is used to light the pilot light. A small amount of gas comes from the gas pipe and then – through a small tube called the ‘pilot tube’.

The thing is also home to a valve that cuts the gas to the pilot light in case something goes wrong (if there is no flame, for example). 

heater pilot light
*A fireplace pilot light is shown here.

There won’t be enough gas flow if the pilot tube is blocked. That means that your propane heater won’t be working.

All you would have to do – is clean the small tube.

First of all, don’t forget to turn the gas off. Only after that, you can take a needle or a wire and gently poke it into the top of the tube.

Usually, you’ll be able to remove the dirt and carbon particles. At times, you might even get a small nest out of the tube – insects can live there during the summer months.

It is very easy to check if your pilot tube needs to be cleaned. A good flame should be bluish and straight, but if the flame is flickering and yellow or orange, then the tube needs to be cleaned as soon as possible.

Read: Why Does My Gas Fireplace Keep Shutting Off?

The Gas Canister Is Empty or Overfilled

Perhaps, one of the most obvious reasons for your propane heater not working might be an empty tank.

Check the gas cylinder to make sure that there is enough propane and then make sure that the gas valve is in the ‘on’ position. If there is not enough gas, call a fuel delivery company that is going to fill the tank for you.

An empty tank is bad, but an overfilled one can be just as problematic (and more dangerous).

Fact: containers with propane should be filled to only 80% of their capacity.

As the temperature rises, the propane in the tank is going to expand. As a result, the pressure inside the container will increase.

If your tank is overfilled, the propane heater might fail to work. In the worst-case scenario, the tank is going to explode.

Here are a few signs that your container is overfilled:

  • There is an overwhelming smell of gas. If the tank is overfilled, propane will be escaping the container.
  • You might even see a vapor stream of liquid propane coming out of the tank.
  • If the gauge is high after the container is filled, then there is too much propane in the tank.
  • The relief valve is released and you can hear the sounds of propane shoots coming from the tank.

Warning! Do not drain an overfilled tank yourself. Clear the area and call a team of professionals. 

The final tank-related thing that you would want to do is check the container and all the connections for possible leaks.

Simply pour some dish soap into a spray bottle or a bowl. Use a sponge or the spray bottle to apply the soapy water to the tank’s valve and regulator.

If you see bubbles forming, then your tank has a leak and you should act immediately.

Also, visually inspect the tank to make sure that there are no cracks or holes.


Last but not least – your propane heater not working might be due to something wrong with the actual unit, but because of the weather conditions. 

If you want your heater to function properly, then you would have to find a perfect place for the unit. 

Of course, the heater has to be protected from drafts, but there are a few other things that you have to bear in mind safety-wise:

  • All propane tanks that are not in use have to be placed at least 20 feet away from the heaters.
  • The heater should be placed at least 6 feet away from doorways, areas with heavy foot traffic, and walls.
  • A propane heater has to be put in a well-ventilated area. For example, it is not advised to place a propane heater in a closed garage.
  • Because of the fact that propane shares oxygen in the room, you would have to make sure that there is a way for oxygen to enter the room. Otherwise, the enclosed space can get depleted of oxygen and/or the heater will shut off (the majority of units have a low-oxygen safety shut-off).
  • Finally, don’t use a propane heater inside, unless it has a clear indication of indoor use in the manufacturer’s manual.

Top Reasons Why the Pilot Light Doesn’t Stay Lit

The Propane Heater Is Located in the Wrong Place

If you have an outdoor propane heater, you have to make sure that the unit is protected from the wind. Otherwise, the pilot light simply won’t be able to stay lit.

Either relocate the heater or get a wind barrier.

The Pilot Light Is Dirty

A pilot light is a small flame that serves as an ignition source (it lights the gas coming out of the pilot tube).

How it fails:

The pilot light can get dirty and clogged with carbon residue and soot. A dirty pilot won’t be able to stay lit, so you would have to clean it at least once a year (more often, if necessary).

How to fix:

The first thing to do is turn the gas off and wait for at least 5 minutes.

  • Removing a pilot light from a propane heater should be relatively easy. Locate the component, take off the bracket that’s holding the pilot and use a wrench to loosen the nuts.
  • Use a brush to scrub off any buildup. You can try using a wire brush, but make sure not to damage the element.
  • Use an air compressor or canned air to blow inside the pilot. This will help remove any debris that you weren’t able to get rid of with a brush. 
  • Put the pilot light back in the propane heater.

Tip: In a lot of models, you can remove the pilot light and the thermocouple simultaneously. This will come in handy if you are planning on cleaning both of the components.

As stated above, do not use cleaning products on the thermocouple or pilot light as chemicals can be flammable.

The Thermocouple Is Dirty

One part of the thermocouple is sitting directly in the pilot light’s flame, while the other is responsible for sending electricity to the gas valve.

heater thermocouple

How it fails:

The thermocouple is a safety device that is going to shut the gas valve, if there is no pilot light. A dirty or faulty element can make the pilot light go out as it will prevent the gas from getting to the pilot light in the first place.

How to fix:

Cut off the gas supply to the heater and wait for at least 5 minutes before proceeding with the next steps.

  • Locate the thermocouple and use a screwdriver to loosen the screws.
  • Carefully remove the element from the pilot assembly.
  • You can use the rough side of a sponge or steel wool to gently remove any dirt and buildup from the thermocouple.
  • To go the extra mile, you can clean the threads of the element’s attachment screw with a pencil eraser.
  • Put the thermocouple back in the pilot assembly.

The Heater’s Orifice Is Dirty

An orifice is a small detail that looks like a tiny brass cup. It dispenses fuel into the burner through a high-precision hole.

heater fuel orifice

It helps ensure that the right amount of propane is mixed with the right amount of air to create the perfect flame for your propane heater. 

How it fails:

Even this part of the heater can get clogged with dirt. Of course, there will be no flame in the unit, if the orifice is clogged.

How to fix:

shut the gas off and leave the unit for a few minutes.

  • Remove the burner shield by unscrewing the screws.
  • Find the control knob and pull it straight off.
  • There might be a panel right behind the knob. If there is one, you would have to remove it.
  • Now that you can see the gas valve assembly, remove the bottom pilot light cover.
  • Remove the screw that’s holding the pilot assembly and pull the gas line out of the housing.
  • Remove the orifice from the mounting bracket.
  • Soak the part in a mixture of water and vinegar.
  • Use an air hose with a high-pressure nozzle to blow out the orifice.
  • Make sure that the component is clean and dry and put it back into the unit.

How to Reset a Propane Heater After You Run Out of Gas

  1. Open the access door on the heater and turn the control to the ‘off’ position.
  2. Close the empty tank by turning the handle counterclockwise. Use a wrench to unscrew the hose from the outlet.
  3. Replace the used tank. Screw the hose back on the fresh tank.
  4. To open the tank, turn the valve clockwise.
  5. Locate the control knob inside the heater, turn it to ‘pilot’, and push it in. Light the pilot light.
  6. After the pilot lights, continue holding the knob for around 30 seconds. This will give the thermocouple enough time to heat up.
  7. Make sure that the pilot light stays lit after you stop holding the knob.
  8. Turn the control to the ‘on’ position and close the access door.

Final Thoughts: Propane Heater Not Working

Overall, propane heaters are not super complex appliances. If you go through each step above, you’re likely to find the culprit behind what’s causing your heater to malfunction.

Just think through the order of operations and what each step needs in order to operate correctly. Testing each item should lead you to finding the one break in the chain.

In most ways, a propane heater functions much like a gas furnace. You may find helpful insights in some of our other articles.

Read: How To Clean A Gas Furnace & My Gas Furnace Is Overheating