What are thermocouples, and why are they so important? Find these answers and several helpful fixes below. 

A lot has been said about how wonderful a solution patio heaters are. Not only are they very easy to use, and relatively inexpensive, but also boast long lifespans when maintained well.

There’s quite a lot to love about them.

But how exactly do they go about providing you with the warmth you’ve come to love? And more importantly. How do they know when it’s time to regulate their internal temperature or shut off?

The answer is simple. By using their thermocouples.

While these components are not exclusive to patio heaters, they work wonders to keep them in tip-top shape.

Now, as remarkable and popular as they are, a fail proof model is yet to be invented. From time to time, these can malfunction, and turn your life upside down. A fact you’re learning the hard way as you read this.

Lucky for you, I did some research when mine failed, and found useful information. Information that I now want to share with you.

Below, you will find a list with the most common causes to a malfunctioning thermocouple, and the simplest steps you can take to address them. I’m certain that, if you stick to them religiously, you’ll be able to fix this part in the blink of an eye.

Are you ready? Let’s dig in!

Fixing a Malfunctioning Thermocouple

At this point, it has probably become clear to you how important this part is to your patio heater’s proper functioning. Not only does it help control your temperature settings, but also prevents overheating, and other potentially dangerous events.

It’s vital to fix your thermocouple as soon as possible, but we must never sacrifice detail and order in the process.

Without further ado, here are some of the most common thermocouple malfunctions you may be experiencing:

  • Compromised gas flow
  • Inaccurate temperature readings
  • Loose wiring
  • Improper grounding
  • Normal wear and tear

#1 Compromised Gas Flow

The first thing I want us to look at, is how well gas is travelling through your unit’s internal components and gas line.

Insufficient or compromised gas flow can occur as the result of several factors, such as a torn gas line, a dirty pilot, or a defective propane canister. All these conditions are dangerous, and could be affecting the way in which your thermocouple is working.

In order to detect your patio heater’s temperature accurately, your thermocouple needs an uninterrupted supply of gas. Before deeming this part as faulty, it is very important that you first rule out other factors that could be impacting it.

Solution: Since there are so many things that could be hindering gas flow, you’ll have to take some time, and check them all.

Start by looking at how clean your pilot is and then proceeded to inspect your gas line for damage. If you’ve never done this before, we have some great guides on how to remove, replace, and clean these components in the sections below.

Make sure to check them out!

#2 Inaccurate Temperature Readings

person adjusting heater control
A malfunctioning thermocouple could put you in a dangerous position

Assuming gas flow is not your problem, we can safely move on to another issue that is just as common, if not more.

I’m talking, of course, about inaccurate temperature readings.

As you know, your thermocouple is responsible for both detecting and regulating the internal temperature in your patio heater, as well as adjusting the heat settings you dial in.

When this part works normally, you should not be encountering any problems. However, sometimes the component can start acting up, and read temperatures wrong.

This would result in the patio heater shutting off randomly, or not even turning on, as the thermocouple could be sensing extreme overheating, even when the appliance is at room temperature.

As you can imagine, this is extremely dangerous, since things could also go the other way. Your unit could be overheating, and your thermocouple would not be able to sense it, thus failing to shut the heater off, and causing potentially permanent damage.

Solution: In most models, the thermocouple is next to the pilot. To access and test it, please follow these steps:

  1. Carefully cut off gas supply to the appliance, and let it cool down completely
  2. Undo the screws connecting the heater’s head to the rest of the body
  3. Place the head somewhere where you can work comfortably on it
  4. Locate the thermocouple, and inspect it for any kind of damage or malfunction

Provided that the part is, in fact, damaged, you’ll have to replace it. You should be able to get a new thermocouple from either your nearest hardware store or your manufacturer.

If you are a visual person like me, and enjoy detailed walkthroughs, there are tons of online videos you can check out and follow along step by step.

#3 Loose Wiring

This is much more likely to be your problem if you’ve owned your patio heater for a while. However, it’s not unheard of that improper installation could also leave some wires badly connected.

In theory, if you had a professional help you install your appliance, every wire should have been attached adequately. But as time passes, and you move your heater from one place to another, some issues can arise.

Your thermocouple relies heavily on a couple of wires that help it both sense, and regulate the temperature inside your unit. Any kind of damage to these connections could greatly compromise the component’s ability to do its job.

As stated above, it is very important that you do not put this off for too long, as your patio heater could overheat.

Solution: If you’ve followed the steps from the previous points, you already have comfortable access to your thermocouple, and its respective wires.

Look closely, and search for signs of damage or anything suspicious. While spotting a damaged or detached wire should be simple enough, keeping your wiring diagram handy, can make your life much easier.

If at any point during this process you feel doubtful, do not hesitate to call a professional. Doing your own repairs is great, but not if you’re risking doing more damage to the unit.

#4 Improper Grounding

grounding of electrical wires
Grounding is essential to prevent electrical problems

Depending on your patio heater model, your thermocouple might be grounded or ungrounded.  If you own the former, the connection to achieve this should only be at one point, not two.

Let me elaborate.

Grounding any component is done with the purpose of protecting both appliances, and people alike. This is used to contain the effects of power surges, and other electricity-related hazards.

When you mistakenly ground your thermocouple in two different points, you could create what is known as a ground loop. This can cause interference in the electromagnetic field.

I won’t bore you with the technical details of what this means, but, in a nutshell, it makes it difficult for this part to get accurate readings and work normally.

Solution: Please follow the steps from point #2 to gain comfortable access to your thermocouple.

Once you have done that, use a multimeter to test it for continuity, and determine whether it’s properly grounded.

#5 Normal Wear and Tear

If none of the solutions above have worked for you, considering that your thermocouple might need to retire, is not too crazy.

Most manufacturers claim that thermocouples should last anywhere between 10 and 12 years if maintained well. However, this lifespan can be dramatically reduced with overheating, or neglect.

If you’ve owned your patio heater for a longer than that, or suspect the part has sustained some damage over the years, it might be a good time to get a new one. In most cases, old thermocouples won’t stop working, but they will start giving off very inaccurate temperature readings, which is a problem in and of itself.

Solution: Please follow the steps from point #2, and test your thermocouple. If you determine it’s time to get a replacement, you can easily purchase one from your nearest hardware store.

When Should You Call a Pro?

The answer to this question will depend greatly on the status of your warranty and whether the solutions above worked for you.

If you’re still under coverage and don’t mind waiting a couple of days or weeks for your manufacturer to send a technician to your home, by all means, go ahead and give them a call.

Unless specified otherwise, they should take care of the repairs for free.

Normally, repairing a faulty thermocouple is not expensive. But if it’s been malfunctioning for a long time, it could have caused damage to other internal components. In that case, you’ll have to weigh the cost of repairs vs the cost of getting a brand-new heater.


Thermocouples are the lifeblood of your appliance. Without this essential part, your patio heater would not be able to self-regulate its temperature and work the way you want it to.

While it’s true that these components can fail from time to time, I hope you’ve learned that fixing them is neither difficult, nor time-consuming.

Trust in your DIY skills, but do not hesitate to call a technician if you’re not sure about what you’re doing.

Thank you for reading. If you found this article helpful, why not become an expert in the subject through our other incredible resources below?

I wish you nothing but the best!