The basic steps to relight a wall heater pilot

To light the pilot on a wall heater, you need to locate the control knob (usually labeled "Pilot," "On," and "Off"), turn it to the Pilot position, press and hold it down, and use a long lighter or match to ignite the small flame at the pilot opening. Hold the knob down for 30 to 60 seconds after the flame catches so the thermocouple—a safety device that detects heat—can warm up and signal the gas valve to stay open. Once you release the knob, the pilot should stay lit. If it goes out when ready, the thermocouple may need cleaning or replacement.

The exact location of the pilot opening varies by heater model. On most wall heaters, it sits near the bottom of the unit, sometimes behind a small access panel or visible through a viewing window. Check your heater's manual or the label on the unit itself to find the pilot opening before you start.

Key Takeaways

  • Turn the control knob to Pilot, press and hold it, and light the pilot opening with a long lighter or match while holding the knob down.
  • Keep the knob pressed for 30 to 60 seconds after ignition so the thermocouple can warm and hold the gas valve open.
  • If the pilot goes out as soon as you release the knob, the thermocouple is likely dirty or faulty and may need cleaning or replacement.
  • Never force the knob or explore excessive pressure; if it does not turn smoothly, stop and consult the manual or a technician.

Locate the pilot opening and control knob

Before you attempt to light the pilot, find both the control knob and the pilot opening on your specific heater. The control knob is usually mounted on the front or side of the unit and has three positions: Off, Pilot, and On. Some models have a fourth position for a thermostat setting.

The pilot opening—a small brass or steel tube—is typically located at the base of the heater or inside a combustion chamber. Many wall heaters have a small window or access panel so you can see the pilot flame once it is lit. If you cannot locate either part, refer to the manual that came with your heater or search online for the model number, which is usually printed on a label inside the unit or on the back.

Turn the knob to Pilot and prepare to ignite

Rotate the control knob to the Pilot position. Do not force it; it should turn smoothly. Once it is set to Pilot, the gas valve opens slightly and allows a small amount of gas to flow to the pilot opening. You will not see or smell gas at this stage if the system is working correctly.

Gather a long lighter or long fireplace match before you proceed. A standard lighter or short match will not reach the pilot opening safely, and your fingers could get too close to the flame. Keep the lighter or match ready in one hand while your other hand stays on the control knob.

Press, hold, and light the pilot flame

Press the control knob inward and hold it down firmly. This action opens the gas valve fully at the pilot opening. While holding the knob down, bring the flame from your lighter or match to the pilot opening. You should see a small blue flame ignite within a few seconds.

If the flame does not appear after 10 to 15 seconds, release the knob, wait a minute for any gas to clear, and try again. Do not hold the knob down for more than a minute without a flame appearing, as this can flood the combustion chamber with gas.

Hold the knob down to let the thermocouple warm

Once the pilot flame is lit, continue holding the knob down for 30 to 60 seconds. During this time, the thermocouple—a small metal probe near the pilot flame—heats up and sends an electrical signal to the gas valve telling it to stay open. If you release the knob too soon, the thermocouple will not be warm enough to hold the valve open, and the pilot will go out.

Watch the pilot flame through the viewing window if your heater has one. The flame should be steady and blue, not yellow or orange. A yellow or orange flame suggests incomplete combustion and may indicate a dirty pilot opening or air supply problem.

Release the knob and turn it to On

After 30 to 60 seconds, slowly release the control knob. The pilot flame should remain lit. If it stays on, turn the knob to the On position. The main burner should ignite, and you will hear a slight whoosh as the larger flame comes to life. The heater is now operating normally.

If the pilot goes out as soon as you release the knob, the thermocouple is not holding the signal. Wait a few minutes and try the process again. If it fails a second time, the thermocouple may be dirty, misaligned, or faulty and will likely need professional attention.

Troubleshooting when the pilot will not stay lit

A pilot that lights but goes out when ready usually points to a thermocouple problem. The thermocouple may be coated with dust or soot, preventing it from heating properly. Some thermocouples can be cleaned carefully with fine sandpaper or a soft brush, but this requires removing the thermocouple from the heater—a task best left to a technician unless you are comfortable working with gas appliances.

If the pilot flame is yellow or orange instead of blue, the pilot opening may be clogged with debris. A clogged opening restricts gas flow and prevents the thermocouple from reaching full temperature. Cleaning the pilot opening requires a thin wire or specialized tool and should be done by someone familiar with gas heater maintenance.

If you smell gas while attempting to light the pilot, or if the pilot will not light after three attempts, stop when ready, turn the knob to Off, open windows for ventilation, and contact a technician or your gas provider. Do not attempt further troubleshooting.

Frequently Asked Questions

How long should I hold the knob down after the pilot lights?

Hold it for 30 to 60 seconds. This gives the thermocouple time to warm up and signal the gas valve to stay open. If you release it too soon, the pilot will go out. If you hold it longer, it does not hurt, but 60 seconds is usually enough.

What if the pilot lights but goes out when I turn the knob to On?

This usually means the thermocouple is not working properly. Try relighting the pilot and holding the knob down for the full 60 seconds. If it still goes out when you switch to On, the thermocouple likely needs cleaning or replacement by a technician.

Can I use a regular lighter instead of a long lighter?

A regular lighter can work, but a long lighter or fireplace match is safer because it keeps your hand farther from the flame and the hot heater. If you use a regular lighter, be careful not to burn your fingers on the heater or the flame.

Why is my pilot flame yellow instead of blue?

A yellow or orange flame usually means the pilot opening is clogged with dust or debris, or the air-to-gas ratio is off. This prevents the thermocouple from heating properly and can cause the pilot to go out. A technician can clean the opening or adjust the air shutter to restore a blue flame.

Is it safe to light the pilot myself, or should I call a technician?

Lighting the pilot is a standard maintenance task that most homeowners can do safely by following the steps in your heater's manual. If the pilot will not stay lit after two or three attempts, or if you smell gas, stop and call a technician. Do not attempt repairs beyond relighting the pilot.