Furnace not heating

Rheem 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.

Rheem'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."
  • "Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions."
  • "If you cannot reach your gas supplier, call the fire department."
  • "Do not return to your home until authorized by the gas supplier or fire department."

Rheem, Installation instructions, (-)95T and (-)(-)95MSX, 92-24161-120-16, 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.

Rheem's own words:

  • "SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT OFF, CLOSE THE MANUAL GAS VALVE FOR THE APPLIANCE BEFORE SHUTTING OFF THE ELECTRICAL SUPPLY. FAILURE TO DO SO CAN CAUSE AN EXPLOSION OR FIRE RESULTING IN PROPERTY DAMAGE, PERSONAL INJURY OR DEATH."

Rheem, Installation instructions, R801T, 92-24161-144-12, page 38

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

Do not push it again. Call a technician.

Rheem's own words:

  • "DO NOT jumper or reset this switch. If this switch should trip, a qualified installer, service agency or the gas supplier should be called to diagnose and/or correct the source of tripping."

Rheem, Installation instructions, R801T, 92-24161-144-12, page 47

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 Rheem 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 Rheem prints for your model's board, quoted with its edition and page. The documents held here for Rheem: 6. 6 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 Rheem

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

  • R801T: Rheem 92-24161-144-12, SUPERSEDES 92-24161-144-11 (an earlier line)
  • R92T: Rheem 92-24161-154-03, SUPERSEDES 92-24161-154-02 (an earlier line)
  • R95T: Rheem 92-24161-120-16, SUPERSEDES 92-24161-120-15 (an earlier line)
  • R96T: Rheem 92-24161-157-04, SUPERSEDES 92-24161-157-03
  • R96V: Rheem 92-24161-124-12, SUPERSEDES 92-24161-124-11 (an earlier line)
  • R97V: Rheem 92-24161-126-04 (an earlier line)

What it cannot answer yet

For these, the page says so instead of guessing:

  • Ruud: no document held names a Ruud furnace, so no Ruud code is decoded
  • Rheem's current Endeavor models (R951T, R951V, R921T, R962V, R972V, R97MV, R98MV, R802V): Rheem's own document library stops in December 2017
  • Rheem 80% furnaces other than the R801T

Questions

What should I do if my Rheem 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. Rheem'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.