How to Replace the Flame Sensor on Your Gas Dryer

Your gas dryer starts up, tumbles fine, and you can hear the igniter clicking, but it never actually heats. Or maybe it heats for a few minutes and then goes cold, leaving you with a drum full of damp clothes and a growing sense of frustration. Nine times out of ten, the flame sensor is your culprit. The good part? This is one of the most straightforward gas dryer repairs out there, and you can knock it out in about 20 minutes.

What the Flame Sensor Does and Why It Matters

The flame sensor is a small component mounted near the igniter and burner assembly inside your gas dryer. Its job is simple but critical: it monitors whether the igniter has reached the right temperature to ignite the gas, and it confirms that a flame is actually present once the gas valve opens.

Gas dryers typically use two or three of these sensors working together, sometimes called radiant flame sensors or heat sensors. One monitors the igniter temperature and signals the gas valve to open. Another watches for an active flame and keeps the gas flowing as long as combustion is happening. If any sensor in that chain fails, the control board shuts down the gas valve as a safety measure. No flame confirmation, no gas. That’s why a bad flame sensor can make your dryer tumble endlessly without ever producing heat.

These sensors are thermal fuses of a sort; they open and close an electrical circuit based on temperature. Over thousands of heating cycles, the bimetallic disc inside the sensor fatigues and stops responding accurately. It is completely normal wear and tear, and we see it constantly.

Signs Your Flame Sensor Has Failed

Here is what to watch for:

• The dryer tumbles but produces no heat at all

• The igniter glows bright orange, but the burner never lights

• The dryer heats intermittently, works for a few minutes, then goes cold, then cycles back on

• Clothes are still damp after a full cycle

• You hear the gas valve click but no flame follows

• The dryer runs excessively long drying cycles

That intermittent heating pattern is a telltale sign. A sensor that is on its way out might still work when it is cool but fail once it heats up. If your dryer seems fine for the first five minutes and then quits producing heat, that is classic flame sensor behavior.

Tools You’ll Need

This repair requires almost nothing in terms of tools:

• Quarter-inch nut driver or 5/16-inch nut driver (varies by brand)

• Phillips-head screwdriver

• Multimeter

• Needle-nose pliers (helpful for removing wire connectors)

That is the full list. We have done hundreds of these, and you will spend more time pulling the dryer away from the wall than you will on the actual repair.

Before you touch anything, unplug the dryer from the wall and shut off the gas supply valve. The gas shutoff is typically on the supply line behind the dryer, turn the valve perpendicular to the pipe so gas flow stops completely. This is non-negotiable on any gas appliance repair for safety.

How to Test the Flame Sensor

If you want to confirm the flame sensor is bad before ordering a replacement, a quick multimeter test will give you a definitive answer.

1. Unplug the dryer and pull it away from the wall so you can access the back panel or the front lower panel, depending on your model.

2. Locate the flame sensor near the burner assembly. On most dryers, you will find it by removing the lower front access panel or the rear service panel. The sensor is a small, round or oval metal disc with two wire leads, mounted close to the igniter and burner tube.

3. Disconnect the wire leads from the sensor. Needle-nose pliers help here; pull on the connector, not the wire itself.

4. Set your multimeter to the continuity or resistance (ohms) setting.

5. Touch one probe to each terminal on the sensor.

At room temperature, a working flame sensor should show continuity, essentially zero ohms or very close to it. If you get an open circuit reading (OL or infinity), the sensor has failed and needs to be replaced.

Keep in mind that some dryers use a cycling thermostat and a high-limit thermostat in addition to the flame sensor, and they can all look similar. The flame sensor sits closest to the igniter and burner assembly. If you are unsure which component is which, take a photo of the wiring before you disconnect anything; it makes reassembly foolproof.

Replacing the Flame Sensor Step by Step

Once you have confirmed the sensor is bad, the swap takes just a few minutes. Here is the process:

1. Make sure the dryer is unplugged and the gas supply is turned off.

2. Remove the lower front access panel or rear service panel. Most panels are held on by two to four screws or spring clips, depending on the brand. On many Whirlpool, Maytag, and Kenmore models, the lower panel pops off by releasing two spring clips at the top.

3. Locate the flame sensor on the burner housing. It is usually secured with a single mounting screw, either a quarter-inch hex head or a Phillips screw.

4. Disconnect the wire leads from the sensor terminals. Note which wire goes where. On most models, the wires are different colors, but a quick photo with your phone is cheap insurance.

5. Remove the mounting screw and pull the old sensor free.

6. Position the new sensor in the same spot and orientation as the old one. The sensing end needs to face the burner flame, if it is pointed the wrong direction, the sensor cannot do its job.

7. Thread the mounting screw back in and snug it down. Do not overtighten. These are small screws going into sheet metal, and stripping the threads will create a new problem.

8. Reconnect the wire leads to the correct terminals.

9. Reinstall the access panel.

10. Turn the gas supply back on and plug the dryer in.

Here is what catches most people off guard: some dryers use a sensor kit rather than a single sensor. That kit usually includes two sensors and sometimes a thermal fuse, all sold together. If your dryer has been running for years and one sensor failed, the others are likely on borrowed time too. Replacing the full kit while you are in there saves you from opening the dryer again in a few weeks. When you’re ready to find the right part, grab your model number and find the exact part for your model; the kit versus individual sensor question depends entirely on your specific dryer.

Testing Your Repair

After everything is buttoned up, run the dryer on a timed heat cycle for a few minutes and confirm the following:

1. The igniter glows.

2. The gas valve clicks open, and a flame appears at the burner.

3. The flame stays lit for the duration of the cycle, not cutting in and out every 30 seconds.

4. The dryer produces steady, consistent heat.

Toss a load of damp towels in and run a full cycle. If the towels come out hot and dry, you are done. If the igniter still glows but the gas never lights, double-check that the gas supply valve is fully open and that the wire connections on the new sensor are seated firmly. A loose spade connector is the most common cause of a “repair that did not work.”

If your dryer heats but seems to cycle on and off more than expected, you may also want to check out our guide on how to replace the sensor dry control board in an electric Whirlpool dryer; the diagnostic approach for control board issues overlaps with gas dryers that have erratic cycling behavior.

Need More Help?

If you run into anything unexpected during this repair, a wiring configuration that does not match what we described, a sensor location that seems off, or a dryer that still will not heat after the swap, head over to our repair help forum. Our techs and community members can walk you through the specifics for your exact model. Post your model number and what you are seeing, and someone will get you pointed in the right direction.

Written by: AppliancePartsPros Team