How do I know if my thermopile is bad?

Just like the thermocouple, the thermopile can be read with a multimeter to check if it’s the cause of the problem. Three hundred millivolts or higher voltage is a sign of a good thermopile. A reading below 300 millivolts would require you to replace the thermopile.

How do you test a millivolt gas valve?

Quote from the video:
Quote from Youtube video: Lower I would have to turn clockwise. And to adjust the flame higher I would have to turn it counterclockwise.

Why does my gas fireplace turn on by itself?

The most likely cause of this problem is that wiring is burned or shorted out. Two low voltage wires extend from the remote control receiver to the gas valve, and perhaps from a separate toggle switch to the gas valve.

What does a thermocouple look like on a gas fireplace?

Quote from the video:
Quote from Youtube video: The thermocouple is thinner and it has a pointed.

How do you test a millivolt on a thermopile?

Quote from the video:
Quote from Youtube video: You'll know the pilot is lit as the voltage will start to climb. Continue to hold down the gas controls thermostat knob until maximum voltage is reached.

What are the symptoms of a bad thermocouple?

If you can’t get the flame to light at all, and you’re sure the gas is on, there’s probably an obstruction in the pilot tube. If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds, that’s the sign of a thermocouple malfunction.

How does a millivolt thermostat work?

Millivolt Thermostats



Unlike low-voltage systems, they do not require a step-down transformer and are not connected to the household wiring system. Instead, they are self-powered by a special thermocouple device called a powerpile or thermopile generator that produces direct current (DC) electricity.

How do I know if my gas valve is bad on my fireplace?

One way to test if your main control valve is bad is by testing resistance. We can do this with our Digital Multimeter. First, find you need to find “Zero” but touching your multimeter leads together. If it reads anything other than zero, you’ll want to subtract this number from the number you will read on the valve.

How does millivolt gas valve work?

Millivolt Gas Valve



This type of valve makes use of a standing pilot that continuously burns to heat a device, either a thermocouple or thermopile, which then produces a small amount of electricity – less than a single volt, hence “milli”-volt.

How do you fix a thermocouple on a gas fireplace?

Quote from the video:
Quote from Youtube video: Set you have to get access to the burner assembly. If you look inside there you can see the thermocouple the thermopile. And the burner.

How much does it cost to replace a thermocouple in a gas fireplace?

between $150 and $250

When replacing a thermocouple or thermopile with the help of a professional, you can expect to pay between $150 and $250.

How do you override a thermocouple?

Quote from the video:
Quote from Youtube video: This is the thermocouple. Okay that's the thermocouple here's a main igniter wire. And here is the tube that gives you propane. So you follow this wire down.

What happens when a thermocouple fails?

When a thermocouple fails, the pilot light won’t stay lighted. A burned out or broken thermocouple should be replaced.

What is the difference between thermocouple and thermopile?

The main difference between Thermocouple and Thermopile is their method of measurement. The thermocouple is a thermoelectric instrument, while the thermopile is an instrument that modifies thermal energy into electrical output.

What can go wrong with a thermocouple?

Sudden loss of heat.



A faulty thermocouple will often “cut out” when it’s experiencing problems, meaning that it misinterprets the pilot light’s temperature and shuts off the gas. This can lead to your heater turning off unexpectedly, even though there’s nothing wrong otherwise.

How do you check a thermocouple?

Quote from the video:
Quote from Youtube video: First thing that we're going to need is our multimeter and we're gonna put it on the own setting first thing we're gonna do is we're gonna test continuity across the thermocouple.

How long does a thermocouple last on a gas fireplace?

Thermocouples can last up to 10 years if properly installed and maintained, while furnaces can last 15-20 years, although either may wear out sooner in multifamily units.

What is the most common thermocouple failure mode?

The most common failure mode for thermocouples is for them to fail open, this is known as thermocouple burnout. Burnout can result from a variety of reasons including the thermocouple experiencing a temperature in excess of that for which it was designed, metal fatigue, and oxidation.

What happens when thermocouple wired backwards?

If you accidentally reverse the polarity of the thermocouple lead wires, the measured temperature will be incorrect by the difference in temperature of the two ends of the leads.