The basic steps to light a wall heater pilot

To light a wall heater pilot, you will turn the control knob to the "Pilot" position, hold down the ignition button while holding a lit match or lighter to the pilot opening, and keep the button pressed for 30 to 60 seconds after the flame catches. Once the pilot stays lit on its own, turn the knob to "On" or your desired temperature setting. The whole process usually takes less than two minutes.

The pilot opening is a small hole near the bottom of the heater, usually marked with a label or arrow. You will need a long lighter or long matches to reach it safely without burning your hand on the heater body. If the pilot does not light after three attempts, or if it lights but goes out when you release the button, stop and check for the problems covered in the sections below.

Key Takeaways

  • Turn the control knob to "Pilot" and hold the ignition button down while lighting the pilot opening with a match or lighter.
  • Keep the button pressed for 30 to 60 seconds after the flame appears so the thermocouple heats up and holds the gas valve open.
  • If the pilot lights but goes out when ready, the thermocouple may be dirty or faulty and will need cleaning or replacement.
  • A pilot that will not light at all usually means the gas is off, the line is blocked, or the igniter is broken.

Locating the pilot opening and control knob

The pilot opening is a small hole on the front or side of the heater, usually near the bottom. Look for a label that says "Pilot" or an arrow pointing to it. The control knob is mounted on the front of the heater and has settings for "Off," "Pilot," and "On" or a temperature range. Some heaters have a separate red ignition button next to the knob; others have the button built into the knob itself.

Before you start, make sure the heater is turned off and has cooled for at least five minutes. Check that the gas supply valve (usually located on the gas line behind or below the heater) is turned on — the handle should be parallel to the pipe, not perpendicular to it. If you smell gas, do not attempt to light the pilot. Turn off the gas valve and wait 15 minutes for the gas to clear before trying again.

Preparing your lighter and positioning yourself safely

Use a long-reach lighter or long fireplace matches so your hand stays several inches away from the heater opening. A standard cigarette lighter or short match will force your hand too close to the hot metal. Test your lighter before you begin to make sure it produces a steady flame.

Position yourself so you can see the pilot opening clearly and reach it comfortably. You will need one hand to hold the lighter or match at the opening and the other hand to press and hold the ignition button. If you cannot do both at once, ask someone to help you hold the lighter while you operate the button. Never lean over the heater or place your face directly in front of the opening.

Lighting the pilot step by step

Turn the control knob to the "Pilot" position. This stops the main burner from firing and allows gas to flow only to the pilot. Press and hold the ignition button — you should hear a clicking sound as the igniter sparks. While holding the button, bring the lit match or lighter to the pilot opening. The pilot should light within a few seconds.

Once you see the flame, keep holding the ignition button for another 30 to 60 seconds. This allows the thermocouple (a heat-sensing device below the pilot flame) to warm up. The thermocouple tells the gas valve to stay open; if you release the button too soon, the valve closes and the pilot goes out. After 60 seconds, slowly release the button while watching the flame. If the pilot stays lit, turn the knob to "On" or your desired temperature. If the flame goes out, wait two minutes and try again.

Why the pilot goes out when ready after you release the button

If the pilot lights when you hold the button but dies as soon as you let go, the thermocouple is not heating up properly. This usually means the thermocouple is dirty or has a weak connection. Turn the knob back to "Off" and let the heater cool for five minutes. Then locate the thermocouple — it is a thin metal rod that sits in the pilot flame, usually held in place by a small nut.

Use a soft cloth or fine steel wool to gently clean the end of the thermocouple that sits in the flame. Wipe away any soot or corrosion. Reposition it so the pilot flame touches the tip directly. Try lighting the pilot again. If it still goes out, the thermocouple may be faulty and will need to be replaced — this is a job for a technician, as it involves disconnecting the gas line.

Troubleshooting a pilot that will not light at all

If you see no spark when you press the ignition button, the igniter is broken and the heater will need professional service. If you hear clicking but see no spark, the igniter may be wet or corroded. Turn off the gas, wait five minutes, and try again. If there is still no spark after three attempts, stop and contact a technician.

If you hear clicking and see sparks but the pilot will not light, the gas may not be reaching the opening. Check that the gas valve on the line is fully open (handle parallel to the pipe). Smell near the pilot opening — if you detect no gas smell, the line may be blocked or the valve may be faulty. Do not attempt to clear a blocked line yourself. If you smell gas strongly but the pilot will not light, the igniter may be too wet. Turn off the gas, leave the heater off for 30 minutes, and try again.

When to call a technician instead of troubleshooting

Stop troubleshooting and call a technician if you smell gas and cannot locate the source, if the pilot lights but the main burner does not turn on when you set the knob to "On," or if you have tried lighting the pilot three times and it will not stay lit. Do not attempt to repair the thermocouple connection, gas valve, or igniter yourself — these parts require special tools and knowledge of gas safety.

If the heater is under warranty, contact the manufacturer or the retailer where you bought it. Many will send a technician at no cost. If the heater is out of warranty, call a local HVAC or appliance repair service. Bring the heater model number (usually on a label on the back or bottom) so the technician can order parts if needed.

Frequently Asked Questions

How long should I hold the ignition button after the pilot lights?

Hold it for 30 to 60 seconds. This gives the thermocouple time to heat up and signal the gas valve to stay open. If you release too soon, the valve closes and the pilot goes out. If you hold it longer, that is fine — just do not hold it for more than two minutes, as this can damage the thermocouple.

What if I smell gas but the pilot will not light?

Turn off the gas valve when ready (turn the handle perpendicular to the pipe). Open windows and doors to let the gas clear. Wait 15 minutes, then try again. If you still smell gas after the second attempt, do not try a third time. Leave the heater off and call a technician or your gas company.

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

You can, but it is not safe. A regular lighter will force your hand very close to the hot heater body and the pilot opening. A long-reach lighter or fireplace matches keep your hand several inches away and reduce the risk of burns. They cost a few dollars and are worth the safety benefit.

Do I need to do anything special if the heater has not been used in a long time?

Yes. If the heater sat unused for more than a month, the pilot opening may have dust or debris in it. Before attempting to light it, use a thin wire or straightened paper clip to gently clear the opening. Do not force anything into it. If the pilot still will not light after clearing, the igniter may need service.

What does it mean if the pilot flame is very small or yellow instead of blue?

A small or yellow flame usually means the pilot opening is partially blocked or the gas pressure is low. Turn off the gas and wait five minutes. Use a thin wire to clear the opening gently. If the flame is still small or yellow after relighting, the gas line or valve may need adjustment — call a technician to check the pressure.