Patio Heater Thermocouple Problems [2 Easy Solutions]

Dirt accumulation on and around the thermocouple and defective wire connection is responsible for patio heater thermocouple problems.

If the thermocouple gets faulty, you can’t light up your patio heater. Fortunately, this guide on patio heater thermocouple issues will break down:

  • How does the thermocouple work on a patio heater?
  • What causes the patio heater thermocouple issues?
  • How to replace the thermocouple on the patio heater?
  • And how to bypass the patio heater thermocouple?

So, let’s dive deeper into this guide right here. 

How Does A Patio Heater Thermocouple Work

You can consider the thermocouple as a temp sensor. When the thermocouple senses the heat, the thermocouple will allow the gas to flow through the pilot tube. On the other hand, if it doesn’t detect any heat, it restricts gas flow. 

Generally, a thermocouple works based on the thermoelectric effect. It’s a process that converts thermal energy to electric energy.  A voltage will occur as the two conductors are connected by default. The voltage will vary with temperature changes. 

The intersections of two wires are known as measuring points. And the other end of the connections is known as the voltage reader. A voltage will create when the measuring point detects a temperature change.

Then, you can measure the voltage. If the thermocouple gets damaged, the patio heater won’t stay lit. Consequently, you can’t feel a warm & toasty environment on a chilly evening by sitting on your patio. 

What Does Cause Patio Heater Thermocouple Problems

Here in this chapter, we will highlight the culprits that cause patio heater thermocouple issues. 

1. Dirt & Dust Buildup Around the Thermocouple

If you don’t clean the patio heater regularly, dirt, dust, and spider webs will nest on and around the thermocouple.

This soot buildup on the thermocouple prevents it from detecting heat. Consequently, no gas will flow through the pilot tube, and the patio heater won’t light up. 


Patio heater thermocouple cleaning will be a piece of cake if you know how to do it. Just remove the screws by using a screwdriver to access the thermocouple. Then, use a damp rag to eliminate dirt, dust, and soot from the thermocouple.

You can also use an air compressor to blow away the dirt & debris from on and around the thermocouple. Also, don’t forget to clean the flame screen with a damp cloth. 

2. Faulty Wire Connection

A defective thermocouple wiring connection is another culprit behind a thermocouple issue. If the wiring gets damaged by discoloration, cracks, and corrosion, you can’t turn on your patio heater. 


Firstly, disassemble the unit and remove the emitter grid to access the thermocouple. Ensure you turn off the patio heater. Use a screwdriver to pull out the copper lead and connection. Then, remove the bracket nuts. Afterward, pull out the thermocouple. 

Next, make sure you set the multimeter to ohms and touch the two leads with it. The readout should be zero. Now, use a lighter as a flame source and place the tip of your thermocouple into the flame.

Connect one lead of the meter to one side of the thermocouple. Then, attach the other lead to the end of your thermocouple by the igniter. 

A functional thermocouple will generate a readout of 25 to 30 millimeters. If you get the readout below this, understand the thermocouple is defective. And replacing it with a new one is the only solution. 

Patio Heater Thermocouple Replacement: The How-To Steps

If the thermocouple is defective, you should replace it with a new one. Follow the below steps to change the faulty thermocouple. 

  • Remove the access panel from the back of the burner using a Phillips head screwdriver. So, use the screwdriver and unscrew the two nuts that hold the access panel together.
  • Once you pull out the access panel, you can see everything is connected down the way. There is an assembly that holds the ignition point and the thermocouple. This junction is known as the ignition assembly. 
  • Now, loosen the ignition assembly by unscrewing the screw that holds the assembly in place. 
  • Once you loosen the pilot assembly, you can find a box housing that keeps the igniter part and the thermocouple. So, remove the nut to unscrew the box housing and slide it back.
  • Next, use a pair of pliers to remove the nut that holds the thermocouple in place. And then, pull out the wire connectors with your hand. 
  • Take your new thermocouple and install it. Regarding this, connect the wire connectors with the tilt switch. Then, attach the other end to the gas valve. Secure the connection by using an 8mm wrench. 
  • Now, let the thermocouple and the wiring go through the box housing.
  • Finally, put everything back into its place. 

How to Bypass Thermocouple On Patio Heater

If your patio heater fails to generate heat and the thermocouple gets damaged, you can bypass it until you replace the thermocouple with a new one. Just follow these steps to bypass the thermocouple:

  • Firstly, push the tilt switch wire out of the way and use an 8mm wrench to remove the thermocouple. 
  • Then, pull out the valve housing using a 13mm wrench and remove the valve using a pair of pliers. 
  • Once you remove the spring valve, put the thermocouple back into its place. 
  • Now, gas will flow directly to the burner when you turn on your patio heater. And you will get heat from the heater. 


The patio heater thermocouple gets defective if dirt and dust accumulate on and around the thermocouple. So, we recommend you clean the unit and the thermocouple regularly to avoid the thermocouple issue in the long run. 

On the other hand, if the thermocouple wiring gets loosened, we recommend you change the old thermocouple. Regarding this, check out the steps we mentioned to replace the thermocouple. Also, you can hire a professional to do this task if you are not mechanically inclined. 

About William

William is the founder of He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

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