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Fix a commercial oven that will not heat

We'll confirm the oven turns on, rule out power, then isolate the cause—heating element, thermal fuse, or thermostat for electric; igniter for gas—or tell you when to call a pro.

Troubleshooting · Home appliances
15–45 min
What you'll need
  • Multimeter (for continuity tests)
  • Screwdriver set (Phillips and flathead)
  • Replacement heating element, thermal fuse, or igniter (if tests show a fault)
Step 1 of 11

Quick triage — pick your path

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

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Steps

Goal: Confirm the symptom, rule out power, then isolate the heating fault.

  • Set the oven to bake at 350°F and start a cycle. Confirm the display and interior light work. Wait five minutes and check if the oven interior warms.
  • Good: The oven turns on but stays cold—heating system has failed. Proceed to Check power.
  • Bad: The oven does not turn on at all—different problem (power, control board). See When to get help.

Check power

Goal: Rule out power loss before opening the oven.

  • Verify the oven is powered and the dedicated circuit breaker has not tripped. Commercial electric ovens often use 208V or 240V; both legs must be on. Reset the breaker if tripped.
  • Check the connection behind or beside the oven: electric ovens have a thick cord or hardwired connection; gas ovens have a gas line and a standard 120-volt plug. You should see either a thick cord or hardwire (electric) or a gas line (gas).
  • Good: Power is on. Proceed to Electric path or Gas path based on your oven type.
  • Bad: Breaker keeps tripping—fix that first, or call a pro if the breaker trips immediately.

Electric path

Goal: Test and replace the heating element, thermal fuse, or thermostat on an electric commercial oven.

  • Disconnect power. Open the oven door. Locate the heating element (coiled tube at the bottom or top). Test for continuity with a multimeter. No continuity or visible damage means it has failed—replace with an exact match.
  • If the heating element is good, locate the thermal fuse (small white or silver cylinder). Check your owner’s manual or search “[brand] [model] commercial oven service manual” for disassembly steps if unsure. Test for continuity. Replace if blown.
  • If the thermal fuse is good, test the oven thermostat and temperature sensor per your model’s specs. Replace any that fail.
  • Good: You found and replaced the faulty part. Reassemble and test—the oven should heat.
  • Bad: All parts test good but the oven still does not heat—call a technician.

Gas path

Goal: Inspect and replace the igniter on a gas commercial oven. Gas valve work requires a pro.

  • Disconnect power and shut off the gas supply at the valve behind or beside the oven. Open the oven door and remove the bottom panel or burner cover per your model. Check your owner’s manual or search “[brand] [model] commercial oven service manual” for disassembly steps if unsure.
  • Locate the igniter. Inspect for cracks or breaks. Test for continuity if possible.
  • If the igniter is cracked or failed, replace it. Restore power and gas. The igniter should glow and the burner should light.
  • Good: The igniter glows and the flame lights. The oven heats.
  • Bad: The igniter glows but no flame appears—gas valve issue. Call a technician. Do not work on gas valves yourself.

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—that is an emergency.

Call a commercial appliance technician if:

  • The oven is gas and the igniter glows but no flame appears (gas valve).
  • You have replaced the heating element and thermal fuse and the oven still does not heat.
  • The oven does not turn on at all (power or control board—different problem).
  • You are not comfortable working with electricity or gas.

Verification

  • The oven interior warms within five to ten minutes of starting a bake cycle.
  • No error codes or unusual smells.
  • The heating element, thermal fuse, or igniter (if replaced) tests good and the oven heats consistently.

Escalation ladder

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

  1. Confirm symptom Verify the oven turns on but stays cold; rule out a different problem.
  2. Power Check circuit breaker; commercial electric ovens need both legs of 208V or 240V.
  3. Electric — heating element Test and replace heating element if faulty.
  4. Electric — thermal fuse and thermostat Test and replace thermal fuse or thermostat if faulty.
  5. Gas — igniter Inspect and replace igniter if cracked or failed.
  6. Call a pro Gas smell—evacuate, call 911 or gas utility from outside. Gas valve work or repeated failures—call a commercial appliance technician.

What to capture if you need help

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

  • Oven type (electric or gas)
  • Whether the display and lights work
  • Heating element / thermal fuse / igniter test results
  • Steps already tried

Does the oven turn on but stay cold?

Set the oven to bake at 350°F. Confirm the display and interior light work. Wait five minutes and check if the oven interior warms.

Set the oven to bake at 350°F and start a cycle. Confirm the display and interior light work. Wait five minutes and check if the oven interior warms. Good: oven turns on but stays cold—heating fault. Bad: oven does not turn on at all—different problem (power, control board); call a technician.

Yes No

You can change your answer later.

Is power on and the circuit breaker not tripped?

Commercial electric ovens use 208V or 240V; both legs must be on. May be hardwired.

Verify the oven is powered and the dedicated circuit breaker has not tripped. Commercial electric ovens often use 208V or 240V. Reset the breaker if tripped and retest. Good: power on. Bad: breaker keeps tripping—fix that first or call a pro.

Yes No

You can change your answer later.

Is the oven electric or gas?

Electric ovens have a thick cord or hardwired connection. Gas ovens have a gas line and standard plug.

Check the connection behind or beside the oven. Electric: thick cord or hardwire. Gas: gas line and standard plug. Good: you know the type. Bad: unsure—call a technician.

Electric Gas

You can change your answer later.

Does the heating element have continuity?

The heating element is the coiled tube at the bottom or top of the oven. Test with a multimeter.

Disconnect power. Open the oven door. Locate the heating element (coiled tube at bottom or top). Test for continuity with a multimeter. No continuity: element failed—replace with exact match, reassemble, test. Continuity: element good—proceed to thermal fuse.

Yes (good) No (broken)

You can change your answer later.

Replace heating element and test

Replace the heating element with an exact match. Reassemble and test. The oven should heat if the element was the only fault. If it still does not heat, proceed to check the thermal fuse and thermostat.

Done

Does the thermal fuse have continuity?

The thermal fuse is a small white or silver cylinder. Test with a multimeter.

Locate the thermal fuse. Test for continuity. No continuity: fuse blown—replace with exact match, reassemble, test. Continuity: fuse good—check thermostat. If all test good but the oven still does not heat, call a technician.

Yes (good) No (blown)

You can change your answer later.

Replace thermal fuse and test

Replace the thermal fuse with an exact match. Reassemble and test. The oven should heat if the fuse was the only fault.

Done

Do the thermostat and sensor test good?

A faulty thermostat or temperature sensor can prevent heat.

Test the oven thermostat and temperature sensor per your model's specs. Replace any that fail. If all test good but the oven still does not heat, call a technician.

Done

Is the igniter cracked or showing no continuity?

The igniter glows when the oven calls for heat. A cracked or failed igniter prevents the burner from lighting.

Disconnect power and shut off the gas. Open the oven and remove the bottom panel. Locate the igniter. Inspect for cracks. Test for continuity if possible. 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 issue; call a technician. Do not work on gas valves yourself.

Yes No (glows but no flame)

You can change your answer later.

Replace igniter and test

Replace the igniter with a matching part. Restore power and gas. The igniter should glow and the burner should light. If the igniter glows but no flame appears, the gas valve has failed—call a technician.

Done

Call a technician

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 a commercial appliance technician if: the oven does not turn on at all; the gas igniter glows but no flame (gas valve); you have replaced the heating element and thermal fuse and it still does not heat; or you are not comfortable working with electricity or gas. Never work on gas valves or gas lines yourself.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a commercial oven turn on but not heat?
Electric ovens: a failed heating element, blown thermal fuse, or faulty thermostat. Gas ovens: a bad igniter or gas valve. Commercial ovens may be hardwired; check the dedicated circuit breaker. Check power first, then the heating components.
Can I fix a commercial oven that will not heat myself?
Yes, for electric ovens you can often replace the heating element or thermal fuse with basic tools. Gas ovens: you can inspect the igniter, but gas valve work requires a professional. Never work on gas lines yourself.
When should I call a technician for a commercial oven that will not heat?
If you smell gas, evacuate immediately and call 911 or your gas utility from outside—do not call a technician for an active leak. Call a technician if the oven is gas and the igniter glows but no flame appears (gas valve), or if you have replaced the heating element and thermal fuse and it still does not heat. Gas valve repairs always need a pro.

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