Rheem Furnace Error Codes: What the Display Means

By Ray Bennett · Updated 2 October 2026 · 5 min read · Checked against the maker’s manual

Rheem Furnace Error Codes: What the Display Means

Short answer

Rheem's two digit display shows 0 when all is well, letters like h or C for what it is doing, and numbers for faults. 11, 12 and 13 are flame problems and usually the flame sensor or gas, 44 to 57 are the pressure switches and venting, 22 is the main limit and airflow, 58 and 59 are water, and 14 means flame with the gas valve off.

Newer Rheem gas furnaces show their faults as two characters on a small display on the control board. It shows 0 when nothing is wrong, a letter for what the furnace is doing, and a number when something has gone wrong.

Everything on this page comes from Rheem’s own installation and operation instructions for the R96V two stage furnace, document 92-24161-124. Other Rheem furnaces, especially older ones with a single blinking light, use their own chart, printed inside the furnace door.

Before you start

What to carry: a torch and a pen. Ten minutes.

Gas or electric? These are codes for Rheem gas furnaces. Rheem heat pumps and air handlers use their own.

Check which way up the display is. Rheem’s own manual warns that the code can be read upside down, and that if a code is not on the list, the display may be upside down. It is the first thing to check.

Read it before opening anything. Look through the window in the door. Taking the door off cuts the power.

Two codes where you stop, not troubleshoot. 14: flame present with the gas valve off. Flame where there should be none. Switch the furnace off and turn the gas off to it.

33: the over temperature, or rollout, switch is open. Flame came out of the burners. Find out why before resetting it: what a rollout switch is telling you.

Smell gas at any point? Leave the house and call from outside.

How to read the display

0 is standby and normal. Letters are modes, not faults. Numbers are faults, and Rheem ranks them in two levels.

Check 1Free, two minutes

Tell a mode from a fault

0 means standby. Rheem describes it as the system off, with no thermostat calls and no errors.

Letters are modes, not faults. h is low heat, H high heat, c and C low and high cooling, F the fan, dF a defrost with a heat pump.

Numbers are faults, and Rheem sorts them into two levels. A level 2 fault stops the furnace. A level 1 fault lets it keep running, but not at its best.

A letter and a number taking turns. That is a level 1 fault while the furnace carries on. Rheem gives the example of h alternating with 57: the high pressure switch will not close, so the furnace can only run on low heat.

10 alternating with another code. 10 is the one hour lockout, and it shows alongside the fault that caused it, such as 11.

Every code Rheem lists

Code	What Rheem calls it	Check first
0	Standby, no calls, no errors	Nothing
10	One hour lockout	The code shown with it
11	Failed ignition	Gas on, then the igniter
12	Low flame sense current	Clean the flame sensor
13	Flame lost after established	Flame sensor, gas supply
14	Flame present with gas valve off	Switch off, gas off
22	Main limit switch open	Filter and registers
23	Auxiliary limit switch open	The jumper wire at the board
26	Line and neutral reversed, or poor ground	Electrician
30	Open fuse	A short in the low voltage wiring
33	Over temperature switch, rollout, open	Why flame rolled out
44	Low pressure switch closed, inducer off	The switch
45, 46	Low pressure switch open, inducer running	Vent, drain, inducer
55	High pressure switch closed, inducer off	The switch
57	High pressure switch open, inducer on high	Vent, drain, inducer
58	Water circuit open	The water sensor circuit
59	Water sensed	The condensate drain
60	Blower fault, blower can still run	Technician
61	Blower fault, motor cannot run	Technician
66	Blower cutback	Filter and ducts
68	No blower communications	Technician
81, 82, 84	Return, supply or outdoor air sensor fault	Technician
93	Internal control fault	The control board
99	Remote faults reset performed	Not a fault
d1, d4, d6	Model data or memory card problem	Technician

The codes you can often clear yourself

Four families cover most Rheem faults, and each has a free first check that involves no gas and no wiring.

Check 2

Work the free check for the family

Flame: 11, 12, 13, and 10 after them. Make sure the gas is on at the furnace. After that, low flame sense current usually points to a dirty flame sensor: how to clean a flame sensor safely.

Venting: 45, 46, 57. The inducer is running but the pressure switch never proved the vent clear. Look for snow, ice or a nest in the pipes outside, then the drain trap and the rubber tubes: the five places to look.

Water: 59. On a condensing furnace, water sensed usually means the condensate is not draining. Clear the trap and the drain line: where a condensing furnace’s water goes.

Airflow: 22, 66. The main limit opened or the blower cut back. Change the filter, open every register and move anything off the return grilles: why a furnace overheats and cuts out.

30: the fuse. It blew because something shorted the low voltage wiring, often a thermostat wire. Find that before a new fuse, or it blows again.

When it needs a technician

Check 3

Know when to stop

44 and 55. A pressure switch reading closed with the inducer off is a stuck switch, and it has to be the right part.

60, 61 and 68. Blower motor faults, and on this furnace the blower talks to the control. Motor or board work.

93 and the d codes. The control or its memory card. Rheem warns never to fit a control or memory card from another furnace or another piece of equipment.

26. Reversed wiring or a poor ground, for an electrician.

Anything that clears and returns. The cheap cause was not the real one.

Questions people ask

What does 57 mean on a Rheem furnace?

The high pressure switch is open with the inducer on high speed. If it shows with a small h, Rheem says the furnace is running on low heat because the high stage cannot be proved. Venting and drainage are the free checks.

The display shows a code that is not on the list.

Rheem’s own advice: check the display is not being read upside down. Several codes turn into other codes when flipped.

My Rheem has a blinking light, not a display.

That is a different control with a flash count chart of its own, printed inside the furnace door. The causes fall into the same families: flame, venting, limits and airflow.

What does level 1 and level 2 mean?

Rheem calls a level 2 fault severe enough to stop the furnace, and a level 1 fault one where it keeps running but not at its best.

It says 10 and then works an hour later.

That is the one hour lockout ending and the furnace trying again. It will lock out again for the same reason until the cause is found.

Can I clear a code by switching it off and on?

Often. Write the code down first, so whoever comes out knows what the furnace was reporting.

Sources: Rheem R96V two stage furnace installation and operation instructions, 92-24161-124