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Fix an igniter that will not glow

We'll confirm the igniter does not glow, rule out power and gas, then replace the igniter or tell you when to call a pro.

Troubleshooting · Home maintenance
15–45 min
What you'll need
  • Multimeter (for continuity test)
  • Screwdriver set (Phillips and flathead)
  • Replacement igniter (if tests show a fault)
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Steps

Goal: Confirm the igniter does not glow, rule out power and gas, then replace the igniter or call a pro.

  • Set the thermostat or control to call for heat. Look at the igniter through the sight glass or access panel.
  • Good: The igniter does not glow—igniter or circuit fault. Proceed to Check power and gas.
  • Bad: The igniter glows but no flame appears—gas valve fault. See When to get help. Gas valve work requires a professional.

Check power and gas

Goal: Rule out power loss and gas supply before opening the appliance.

  • Verify the circuit breaker has not tripped. Gas appliances need 120 volts for the igniter.
  • Confirm the main gas shutoff and any local shutoff are fully open (parallel to the pipe).
  • Good: Power on, gas on. Proceed to Replace igniter.
  • Bad: Breaker tripped or gas off—fix those first, then retry.

Replace igniter

Goal: Inspect, test, and replace the igniter if faulty.

  • Shut off power and gas. Open the access panel per your model. Check your owner’s manual or search “[brand] [model] service manual” for disassembly steps if unsure.
  • Locate the igniter. Inspect for cracks or breaks. Test for continuity with a multimeter. No continuity or very high resistance means replace.
  • Buy a matching igniter (check the part number). Disconnect the wires, remove the mounting screws, install the new igniter, and reassemble. Restore power and gas. Call for heat.
  • Good: The igniter glows and the burner lights. The appliance heats.
  • Bad: The igniter glows but no flame appears—gas valve issue. Call a pro. Gas valve work always requires a professional.

When to get help

If you smell gas, evacuate immediately. Do not turn on lights or appliances. Call 911 or your gas utility from outside. Do not call a technician for an active gas leak.

Call an HVAC technician or appliance technician if:

  • The igniter glows but no flame appears (gas valve).
  • You have replaced the igniter and it still does not glow.
  • You are not comfortable working with gas or electricity.

Gas valve work always requires a professional—do not attempt it yourself.

Verification

  • The igniter glows when the appliance calls for heat.
  • The burner lights and the appliance heats as expected.
  • No error codes or lockouts.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm symptom Verify the appliance calls for heat but the igniter does not glow.
  2. Power and gas Check circuit breaker and gas supply.
  3. Inspect igniter Look for cracks or breaks; test for continuity.
  4. Replace igniter Install a matching replacement and test.
  5. Call a pro Gas smell—evacuate, call 911 or gas utility. Igniter glows but no flame—call an HVAC or appliance technician. Gas valve work always requires a pro.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Appliance type and model
  • Whether the igniter glows at all
  • Igniter continuity test results
  • Steps already tried

Does the appliance call for heat but the igniter not glow?

Set the thermostat or control to call for heat. Look at the igniter through the sight glass or access panel. If it does not glow, the igniter or its circuit has failed.

Set the thermostat or control to call for heat. Look at the igniter. Good: igniter does not glow—igniter or circuit fault. Bad: igniter glows but no flame—gas valve fault; call a pro.

Yes No (glows but no flame)

You can change your answer later.

Is power on and gas supply on?

Circuit breaker and gas supply must both be on.

Check the circuit breaker has not tripped. Check the gas shutoff valves—main and local—are fully open (parallel to pipe). Good: power on, gas on. Bad: breaker tripped or gas off—fix those first.

Yes No

You can change your answer later.

Fix power or gas, then retry

Reset the breaker, open gas valves fully. Retry calling for heat. If the igniter glows, the problem was power or gas. If it still does not glow, proceed to inspect the igniter.

Done

Is the igniter cracked or showing no continuity?

Shut off power and gas. Inspect the igniter for cracks. Test for continuity.

Shut off power and gas. Open the access panel. Locate the igniter. Inspect for cracks or breaks. Test for continuity with a multimeter. Cracked or no continuity: replace igniter, restore power and gas, test. Good: igniter glows and flame lights. Bad: igniter glows but no flame—gas valve; call a pro. Gas valve work always requires a professional.

Yes No

You can change your answer later.

Replace igniter and test

Replace the igniter with a matching part. Restore power and gas. Call for heat. The igniter should glow and the burner should light. If the igniter glows but no flame appears, the gas valve has failed—call a pro. Gas valve work always requires a professional.

Done

Call a pro

If you smell gas, evacuate immediately. Call 911 or your gas utility from outside. Call an HVAC technician or appliance technician if: the igniter glows but no flame (gas valve); you have replaced the igniter and it still does not glow; or you are not comfortable with gas or electricity. Gas valve work always requires a professional.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would an igniter not glow?
A cracked or failed igniter is the most common cause. Power loss, a tripped breaker, or a faulty gas valve board can also prevent the igniter from receiving voltage. On some furnaces, a limit switch or pressure switch may block the igniter from energizing.
Can I replace an igniter myself?
Yes. Shut off power and gas, locate the igniter, disconnect it, and install a matching replacement. Gas valve work requires a professional—if the igniter glows but no flame appears, call a pro.
When should I call a pro for an igniter that will not glow?
If you smell gas, evacuate and call 911 or your gas utility from outside. Call an HVAC technician or appliance technician if the igniter glows but no flame appears (gas valve), if you have replaced the igniter and it still does not glow, or if you are not comfortable working with gas or electricity.

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