The basic steps to relight your wall heater pilot
To light a pilot light on a wall heater, you need to locate the control knob (usually labeled "Pilot," "On," and "Off"), turn it to the Pilot position, hold down the ignition button while holding a lit match or lighter to the pilot burner opening, and keep the knob pressed for 30 to 60 seconds after the flame catches. Once the pilot stays lit on its own, turn the knob to the On position. The whole process takes about two minutes if the gas is flowing and the igniter works.
Most wall heaters have the control knob on the front or side of the unit. The pilot burner itself is a small opening you can usually see inside the heater's combustion chamber—it looks like a tiny brass nozzle. If you cannot locate either one, check your heater's manual or the manufacturer's label on the unit itself.
Key Takeaways
- Turn the control knob to Pilot, press the ignition button, and light the pilot burner with a match or lighter while holding the button down for 30 to 60 seconds.
- If the pilot does not stay lit after you release the button, the thermocouple may be dirty or failing, and you should clean it or call a technician.
- A pilot light that goes out repeatedly often means the gas supply is interrupted, the thermocouple is worn, or there is a draft blowing out the flame.
- If you smell gas but cannot light the pilot, turn off the heater and do not attempt to relight it—call your gas company or a technician instead.
Locating the control knob and pilot burner
The control knob is usually mounted on the front face of the heater or on a side panel. It will have three positions marked: Off, Pilot, and On. Some models have a fourth position for a thermostat setting. The knob itself is typically a dial about the size of a quarter, and you turn it by hand—no tools needed.
The pilot burner opening is inside the heater's firebox, visible through the front access panel or combustion chamber window. It is a small brass or steel tube pointing downward or to the side. If the heater has a glass window, you may see the pilot burner directly. If not, you may need to open a small metal door or remove a cover to access it. The ignition button is usually located next to or below the control knob and clicks when you press it.
Step-by-step lighting procedure
First, make sure the heater is off and has cooled for at least five minutes. Turn the control knob to the Pilot position. You should hear a faint hissing sound—this means gas is flowing to the pilot burner.
Next, press and hold the ignition button. If your heater has a piezo igniter (a button that creates a spark), you may hear clicking sounds. If it does not spark or if you prefer a more reliable flame, use a long lighter or a long match instead. Hold the flame near the pilot burner opening while continuing to press the ignition button.
Once the pilot flame ignites, keep holding the ignition button down for 30 to 60 seconds. This allows the thermocouple—a heat-sensing device next to the pilot flame—to warm up and signal the gas valve to stay open. If you release the button too soon, the pilot will go out.
After 30 to 60 seconds, slowly release the ignition button while watching the pilot flame. If it stays lit, turn the control knob to the On position. The main burner should ignite within a few seconds. If the pilot goes out when you release the button, wait a few minutes and try again.
What to do if the pilot will not stay lit
If the pilot lights but goes out as soon as you release the ignition button, the thermocouple is likely dirty or failing. The thermocouple is a thin metal rod positioned in the pilot flame, and it generates a small electrical signal that tells the gas valve to stay open. When it is covered in dust or soot, it cannot sense the heat and the valve closes.
To clean the thermocouple, turn off the heater and let it cool. Locate the thermocouple—it is the thin metal rod closest to the pilot flame. Gently rub it with fine steel wool or a soft cloth to remove any buildup. Do not bend it or explore heavy pressure. Turn the heater back on and try lighting the pilot again.
If cleaning does not work, the thermocouple may be worn out and need replacement. This is a job for a technician, as it involves disconnecting gas lines and requires a steady hand and proper tools. Call a heating professional if the pilot still will not hold after cleaning.
When the pilot light keeps going out
A pilot that lights but goes out repeatedly—even after staying on for a while—usually points to one of three problems: a weak thermocouple, an interrupted gas supply, or a draft.
Drafts are the most common culprit in wall heaters, especially those mounted near windows or exterior walls. Cold air or wind can blow out the pilot flame. If you notice the pilot going out after windy weather or when a door or window opens nearby, check for drafts around the heater. Seal any gaps with weatherstripping or caulk, or consider moving the heater away from the draft source if possible.
An interrupted gas supply means the gas line is being shut off or the pressure is dropping. This can happen if the gas valve is partially closed, if there is a leak upstream, or if the gas company is performing maintenance. Check that the control knob is fully in the On position and that no other valves near the heater are closed. If you suspect a gas leak, do not attempt to light the pilot again—call your gas company when ready.
Safety precautions before you start
Before lighting a pilot on any gas heater, make sure the area is well-ventilated. Open a window or door to allow fresh air to circulate. Do not light the pilot in a sealed room, as this can lead to carbon monoxide buildup.
If you smell gas but the pilot will not light, or if you smell gas after the heater is running, turn off the heater when ready and do not attempt to relight it. Leave the area and call your gas company's emergency line or a licensed technician. A strong gas smell means there is a leak, and lighting a flame could be dangerous.
Never force the control knob or ignition button. If either one is stuck or broken, stop and call a technician. Do not try to disassemble the heater or access the gas lines yourself unless you are trained to do so.
When to call a professional
You should call a heating technician if the pilot will not light after two or three attempts, if it lights but will not stay on even after cleaning the thermocouple, if you smell gas, or if the control knob or ignition button is broken or stuck. You should also call if the main burner does not ignite after the pilot is lit, or if the heater makes unusual noises or smells like burning plastic.
A technician can test the thermocouple with a meter, check the gas pressure, inspect the ignition system, and replace worn parts. The cost of a service call varies by region and by what needs to be fixed, but it is worth the expense to may support the heater is safe and working correctly.
Frequently Asked Questions
How long should I hold the ignition button before releasing it?
Hold it for 30 to 60 seconds after the pilot flame ignites. This gives the thermocouple time to heat up and signal the gas valve to stay open. If you release too soon, the pilot will go out. If you hold it longer, that is fine—just do not hold it for more than a few minutes.
Can I use a regular lighter instead of a match?
Yes. A long lighter or a long match works equally well. The goal is to get a flame close to the pilot burner opening while you hold down the ignition button. A long lighter is often easier to control and safer than a match, especially if the pilot burner is recessed inside the heater.
What does it mean if the pilot lights but goes out when ready?
The thermocouple is likely dirty or failing. Try cleaning it gently with steel wool, then light the pilot again. If it still goes out right away, the thermocouple probably needs to be replaced by a technician.
Is it normal for the pilot to go out during windy weather?
Yes, especially if the heater is near a window or exterior wall. Drafts can blow out the pilot flame. Seal any gaps around the heater or nearby windows, or move the heater if possible. If the problem persists, a technician can install a draft shield or check the heater's combustion air intake.
What should I do if I smell gas but the pilot will not light?
Stop when ready and do not try to light it again. Turn off the heater, leave the area, and call your gas company's emergency number or a licensed technician. A strong gas smell indicates a leak, and attempting to light a flame could be dangerous.