Furnace not heating

Frigidaire, Gibson, Maytag and Intertherm furnace not heating? Read the code for your model

Stop first: these are not a code to look up

If you smell gas

Leave the building now. Do not touch light switches or use a phone inside. From outside, call your gas supplier, or the fire department if you cannot reach them.

Nordyne's own words:

  • "WHAT TO DO IF YOU SMELL GAS"
  • "Do not try to light any appliance."
  • "Do not touch any electrical switch; do not use any phone in your building."
  • "Leave the building immediately."
  • "Immediately call your gas supplier from a neighbors phone. Follow the gas suppliers instructions."
  • "If you cannot reach your gas supplier, call the fire department."

Nordyne, G7S(A,K) MGC2S(A,K) installation instructions (02/25), page 1

If a carbon monoxide (CO) alarm is sounding, or someone feels sick

Get everyone outside into fresh air now, then call 911 or the fire department from outside.

The U.S. Consumer Product Safety Commission's words (none of the furnace makers' documents held here prints what to do when a CO alarm sounds):

  • "Never ignore an alarming CO alarm! It is warning you of a potentially deadly hazard."
  • "If the alarm signal sounds do not try to find the source of the CO:"
  • "Immediately move outside to fresh air."
  • "Call your emergency services, fire department, or 911."
  • "After calling 911, do a head count to check that all persons are accounted for. DO NOT reenter the premises until the emergency services responders have given you permission. You could lose consciousness and die if you go in the home."
  • "If the source of the CO is determined to be a malfunctioning appliance, DO NOT operate that appliance until it has been properly serviced by trained personnel."

U.S. Consumer Product Safety Commission, Carbon Monoxide Fact Sheet, "What should you do when the CO alarm sounds?" (fetched 2026-09-24), page 1

If you see flame while the thermostat is not calling for heat

This is a stop condition. Do not reset or restart the furnace. Call a technician or your gas supplier now.

Nordyne's own words:

  • "WARNING: Should overheating occur or the gas supply fails to shut off, shut off the manual gas valve to the furnace before shutting off the electrical supply."

Nordyne, MG1E A2L installation instructions (02/25), page 22

If a reset button on the furnace tripped again after it was pushed

Do not push it again. Call a technician.

Answer the safety questions first. Then pick the brand, say what you see on the furnace without opening it, and give the model. The code is read from the table Nordyne prints for that model's board, and quoted with its page. Nothing here asks you to open the furnace.

Field brief
Stop first a gas smell, a carbon monoxide alarm, flame while the thermostat is not calling for heat, or a reset button that trips again after it was pushed: each is answered at the top of this page, before any code. before any code
The code, by model read only from the table Nordyne prints for your model's board, quoted with its edition and page. The documents held here for Frigidaire, Gibson, Maytag and Intertherm: 12. 12 documents
No reset step this page gives no reset or repair step, and nothing here asks you to open the furnace. A maker's reset words are shown only as the manual's words for a technician. manual's words only

What this page reads for Frigidaire, Gibson, Maytag and Intertherm

Each code is read from the table printed in Nordyne's own document for your furnace's series, and quoted with its edition and page. The documents held here:

  • (F,V)G8SD / L9X1 / MGC3SD: Nordyne (02/25) footer; portal title (F,V)G8SD L9X1 MGC3SD Ultra-Low NOx ii.pdf v3
  • *G6 / L1 / G7 single stage (Channel board 1046399): Nordyne 10492440 (NEW), (10/24) footer; LED legend on wiring diagram 10492400
  • *G7S(A,K,C,D) / MGC2 / MG3P / MG2R / CMF95 (Channel board 1046397): Nordyne (08/25) footer; portal title Rpl Board Kit-Channel Board ii; LED legend on wiring diagram 10499330 (Figure 3)
  • *G7S(A,K) / MGC2S(A,K): Nordyne (02/25) footer; portal title G7S(A,K) MGC2S(A,K) ii.pdf
  • *G7S(C,D) / MGC2S(C,D): Nordyne (02/25) footer; portal title G7S(C,D) MGC2S(C,D) Gas Furnace ii
  • *G7T(E,N): Nordyne (02/25) footer; portal title G7T(E,N) Two-Stage Furnace ii
  • *G7TA / PGC2TA: Nordyne (02/25) footer; portal title G7TA PGC2TA Two-Stage Gas Furnace ii
  • *G7TC / PGC2TC: Nordyne (02/25) footer; portal title G7TC PGC2TC ii
  • MG1: Nordyne 10502240, (03/25) footer
  • MG1E: Nordyne (02/25) footer; portal title MG1E A2L ii
  • MG2R: Nordyne 1050022A, (04/25) footer
  • MG2S: Nordyne (05/25) footer; portal title MG2S A2L Gas Furnace ii

What it cannot answer yet

For these, the page says so instead of guessing:

  • Miller, Westinghouse, Tappan, Broan and other names no document held prints
  • Nordyne owner's manuals, and the older G6 and M7 furnaces

Questions

What should I do if my Frigidaire, Gibson, Maytag and Intertherm furnace smells like gas?

Leave the building now. Do not touch light switches or use a phone inside. From outside, call your gas supplier, or the fire department if you cannot reach them. Do not look up a code first. Nordyne's own "what to do if you smell gas" words are quoted at the top of this page, with the document they are printed in.

Why does this page ask for the model before it reads a code?

Because the same number of blinks can mean different things on different boards from one maker. The documents held here show it in several families, among them York, Goodman, Lennox, Allied and Nordyne: a count that is a stop condition on one board means something else on another. So a code is read only from the table printed for your model's series, and where two held documents for that series print one code with the same meaning (a misspelling or a unit written two ways) it is answered once and both are cited, while where their meanings differ it asks which unit you have and never guesses.

Can I reset the furnace myself?

This page gives no reset step. Where a maker's table prints reset words for a code, they are shown as the manual's words for a technician. Rheem's installation instructions print "DO NOT jumper or reset this switch" for its rollout switches. If a reset button on the furnace trips again, stop and call a technician. Nothing here asks anyone to open a door.