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Fix a propane heater that will not light

We'll rule out gas smell first, then help you fix a propane heater that will not light—propane, valve, regulator, pilot orifice, igniter, thermocouple—or tell you when to call a pro.

Troubleshooting · Home appliances
10–30 min
What you'll need
  • Long match or lighter (for manual pilot lighting if igniter fails)
  • Needle or pipe cleaner (for clearing pilot orifice and burner ports)
  • Replacement igniter battery (if applicable)
Step 1 of 11

Quick triage — pick your path

Quick triage — pick your path

Choose the option that matches what you see. You can jump straight to that section.

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Steps

Goal: Rule out gas smell, then fix a propane heater that will not light.

  • Step back and sniff. If you smell gas, evacuate and call 911 or your gas utility from outside. Do not troubleshoot.
  • Check propane level, gas valve fully open, and regulator. Proceed to Propane, valve, and regulator.
  • Good: You have ruled out fuel and gas flow. Proceed to Pilot orifice and igniter path.
  • Bad: Gas smell—evacuate. Empty tank or closed valve—fix and retest.

Gas smell check

Goal: Confirm there is no gas leak before troubleshooting.

  • Step back from the heater and sniff. Gas has a rotten egg odor.
  • Good: No gas smell. Proceed to Propane, valve, and regulator.
  • Bad: You smell gas. Evacuate everyone. Do not turn anything on or off. Call 911 or your gas utility from outside.

Propane, valve, and regulator

Goal: Rule out fuel and gas flow issues.

  • Check propane level—gauge or tank weight. A 20-lb tank when empty weighs roughly 18 lb. Replace or refill if empty.
  • Confirm the gas valve is fully open (turn counterclockwise until it stops). Wait a minute for gas to reach the heater.
  • If the heater has not been used in a while, reset the regulator: turn off gas, disconnect hose from tank, wait 30 seconds, reconnect, open valve slowly.
  • Good: Tank has fuel, valve is open, regulator is working. Proceed to Pilot orifice and igniter path.
  • Bad: Empty tank or valve closed—fix and retest. Regulator faulty—replace or call a pro.

Pilot orifice and igniter path

Goal: Fix the pilot and igniter so the heater lights.

  • Turn off the gas. Locate the pilot orifice (small opening near the main burner) and burner ports. Clear with a needle or pipe cleaner—do not enlarge the holes.
  • Turn the control knob to pilot or ignite. Listen for a click and look for a spark at the pilot. If no click, replace the igniter battery. If click but no spark, clean the electrode with a soft brush and check that it is close to the pilot.
  • If the igniter sparks but no flame appears, the gas valve has failed—call a pro. Do not work on gas valves yourself.
  • If the igniter fails but gas flow is confirmed, light the pilot manually with a long match or lighter at the pilot orifice. Hold the knob down for 30–60 seconds to allow the thermocouple to heat, then release.
  • Good: Pilot lights and stays lit. Turn the knob to on to light the main burner.
  • Bad: Pilot lights but goes out when you release the knob—thermocouple may be dirty or faulty. Igniter sparks but no flame—gas valve. Call a pro.

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 troubleshoot an active gas leak.

Call a pro if:

  • The igniter sparks but no flame appears (gas valve issue).
  • The pilot lights but the main burner will not light.
  • You have checked propane, valve, regulator, orifice, igniter, and thermocouple and it still will not light.
  • You are not comfortable working with gas.

Never work on gas valves or gas lines yourself.

Verification

  • Pilot lights when you press the igniter or light manually. Steady blue pilot flame.
  • Pilot stays lit when you release the knob. Main burner lights when you turn the knob to on.
  • No gas smell. No hissing from connections.

Escalation ladder

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

  1. Gas smell check If you smell gas, evacuate and call 911 or gas utility from outside.
  2. Propane, valve, regulator Check propane level, gas valve open, regulator not locked.
  3. Pilot orifice and burner Clear pilot orifice and burner ports of spiders or debris.
  4. Igniter and thermocouple Replace igniter battery, clean electrode, confirm spark; check thermocouple placement.
  5. Call a pro Gas smell—evacuate, call 911. Igniter sparks but no flame—gas valve; call a pro.

What to capture if you need help

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

  • Propane level
  • Whether igniter clicks and sparks
  • Whether pilot orifice and burner ports are clear
  • Steps already tried

Do you smell gas?

Before any troubleshooting, step back and sniff. Gas has a rotten egg odor. If you smell it, evacuate and call 911 or your gas utility from outside.

Step back and sniff. Good: No gas smell—proceed to check propane and valve. Bad: You smell gas—evacuate immediately. Do not turn anything on or off. Call 911 or your gas utility from outside. Do not troubleshoot.

Yes No

You can change your answer later.

Evacuate and call 911

Evacuate everyone from the area. Do not turn on lights or appliances. Call 911 or your gas utility from outside. Do not return until the leak is resolved.

Done

Is propane level sufficient and gas valve open?

Check the tank gauge or weigh the tank. Confirm the gas valve is fully open (counterclockwise).

Check propane level—gauge or tank weight. Open the gas valve fully (counterclockwise). If empty, replace or refill. Good: tank has fuel and valve is open. Bad: empty tank or valve closed—fix and retest.

Yes No

You can change your answer later.

Refill or replace propane, open valve, retest

Refill or replace the propane tank. Open the gas valve fully. Wait a minute for gas to reach the heater. Try to light. If it lights, you are done. If not, proceed to check the regulator and pilot orifice.

Done

Does the regulator need resetting?

Regulators can lock after long periods of non-use. Disconnect, wait, reconnect, open valve slowly.

Turn off gas, disconnect hose from tank, wait 30 seconds, reconnect, open valve slowly. Good: flame is steady. Bad: weak or sputtering flame—regulator may be faulty; replace or call a pro.

Yes No

You can change your answer later.

Are pilot orifice and burner ports clear?

Spiders and debris can block the pilot orifice and burner ports. Turn off gas, clear with needle or brush.

Turn off gas. Locate the pilot orifice and burner ports. Clear with needle or pipe cleaner—do not enlarge holes. Reconnect and test. Good: pilot lights. Bad: still no light—check igniter.

Yes No

You can change your answer later.

Clear pilot orifice and burner, retest

Clear the pilot orifice and burner ports with a needle or pipe cleaner. Reconnect and try to light. If it lights, you are done. If not, proceed to check the igniter.

Done

Does the igniter click and spark?

Turn the knob to pilot. Listen for click, look for spark at pilot. Dead battery or dirty electrode can prevent spark.

Turn the control knob to pilot. Click and spark: igniter works—try lighting; if pilot lights but goes out, check thermocouple. No click: replace igniter battery. Click but no spark: clean electrode, check that it is close to pilot. Igniter sparks but no flame: gas valve failed—call a pro. Do not work on gas valves yourself.

Yes (sparks) No

You can change your answer later.

Replace battery or clean electrode, retest

Replace the igniter battery if no click. If click but no spark, clean the electrode and align it near the pilot. Retest. If the igniter sparks but no flame appears, the gas valve has failed—call a pro.

Done

Does the pilot stay lit when you release the knob?

The thermocouple senses the pilot flame. If pilot goes out when you release the knob, thermocouple may be dirty or faulty.

Light the pilot and hold the knob down for 30–60 seconds. Release. Pilot stays lit: thermocouple is good—turn knob to on to light main burner. Pilot goes out: thermocouple may be dirty, misaligned, or faulty—clean or replace, or call a pro.
Question

Does the pilot stay lit?

Done

Call a pro

If you smell gas, evacuate and call 911 or your gas utility from outside. Call a pro if: the igniter sparks but no flame (gas valve); the pilot lights but the main burner will not light; you have checked propane, valve, regulator, orifice, igniter, and thermocouple and it still will not light; or you are not comfortable working with gas. Never work on gas valves or gas lines yourself.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a propane heater not light?
Common causes: empty or low propane tank, gas valve closed, regulator locked, clogged pilot orifice or burner ports (spiders), failed igniter, or faulty gas valve. Check propane and valve first, then the pilot orifice and igniter. If the igniter sparks but no flame appears, the gas valve has failed—call a pro.
Can I fix a propane heater that will not light myself?
Yes. You can check propane level, open the gas valve, reset the regulator, clear the pilot orifice and burner ports, replace the igniter battery, and clean the electrode. Gas valve or thermocouple replacement may require a technician.
When should I call a pro for a propane heater that will not light?
If you smell gas, evacuate and call 911 or your gas utility from outside. Call a pro if the igniter sparks but no flame appears (gas valve), if the pilot lights but the main burner will not light, if you have checked propane, valve, regulator, orifice, and igniter and it still will not light, or if you are not comfortable working with gas.

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