Why Is My Propane Heater Not Working? Troubleshooting Guide

The most common reasons for a non-working propane heater 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.

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 sensor simply won’t be able to detect the flame. Rust and debris can also become a problem.

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.

  • 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). 

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 why your propane heater might not be working is 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 might fail to work not because there is 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.