1. Home
  2. Carrier
  3. gas furnaces
  4. Code 33.2

Carrier gas furnace code 33.2: High heat only for the current cycle

Gas furnace, Canada and United States

The control locked out low heat, so the furnace runs at high heat only for the current cycle. The checks are the same as for code 33.1.

This needs a licensed gas technician. There are a few safe checks you can do first, marked below. Anything inside the unit is a job for a professional.

This involves the flue or exhaust. A blocked or leaking flue can let carbon monoxide into the home.

Only some models show this code. Check the list below.

What causes it

  1. Not enough air moving through the furnace because of a dirty filter or a restricted duct system, including closed or blocked registers and grilles.

    Shut off the gas to the furnace, then the powerYou can do this

    1. Set the thermostat to its lowest setting and its mode to OFF.
      If you smell gas, stop. Do not light any appliance, touch any electrical switch or use a phone in the building. Leave and call your gas supplier from a neighbor's phone.
    2. Close the manual gas valve in the gas pipe to the furnace.
    3. Only then turn off the electrical supply to the furnace. Carrier says to shut off the gas first whenever the gas does not shut off or the furnace overheats.
    4. Leave the furnace off with its doors on and call your dealer for service.

    Book a licensed gas technician

  2. A flame rollout switch has tripped, which the troubleshooting guides link to an inadequate combustion air supply. A technician must correct the underlying problem before resetting it.

    Same check as above: Shut off the gas to the furnace, then the power

    Book a licensed gas technician

  3. A restricted or wrongly sized vent, or strong wind at the vent.

    Same check as above: Shut off the gas to the furnace, then the power

    Book a licensed gas technician

  4. A loose blower wheel, or a faulty blower motor or capacitor.

    Same check as above: Shut off the gas to the furnace, then the power

    Book a licensed gas technician

  5. A faulty limit switch or connection, or the gas input set wrongly.

    Same check as above: Shut off the gas to the furnace, then the power

    Book a licensed gas technician

How to read this code on your unit

The three-digit display sits on the furnace control behind the blower door. Through the sight glass in the door you see only the status light, which flashes the first two digits of the code. Count the short flashes for the first digit, then the long flashes for the second, so 3 short flashes followed by 3 long flashes is a 33.x code. Write down what you see before you open the door or switch the furnace off. The full code with its third digit shows on the control display only with the door removed and the door switch closed, which is a job for a technician. A technician can also look back at the last 7 faults in the FLt menu. Stored codes are erased by themselves after 72 hours of powered operation after the last fault, and the display shows non when no fault is stored.

Booking a licensed gas technician

Book a licensed gas technicianlicensed gas technician

  1. Turn the unit off and leave the covers on. Gas components must only be serviced by a licensed technician.
  2. Note the code, how often it appears, and the model and serial numbers from the rating label.
  3. Book a licensed gas technician and give them those details.

Models that show this code

29 models in 3 ranges
RangeModels
58TP0B/58TP1B58TP0B045V14-12, 58TP0B070V14-12, 58TP0B070V17-16, 58TP0B090V17-16, 58TP0B090V21-20, 58TP0B110V21-22, 58TP0B135V24-22, 58TP1B045V14-12, 58TP1B070V14-12, 58TP1B070V17-16, 58TP1B090V17-16, 58TP1B090V21-20, 58TP1B110V21-22, 58TP1B135V24-22
59TP6C59TP6C040V14-10, 59TP6C040V17-12, 59TP6C060V14-12, 59TP6C060V17-16, 59TP6C080V17-16, 59TP6C080V21-20, 59TP6C100V21-20, 59TP6C100V21-22, 59TP6C120V24-22
59TP7A59TP7A060V17-16, 59TP7A080V17-16, 59TP7A080V21-20, 59TP7A100V21-20, 59TP7A100V21-22, 59TP7A120V24-22

Where this comes from

Checked against the manufacturer's manual on 27 October 2026.

Report a mistake on this page

Other Carrier gas furnace codes

Code Meaning What you can do
13 Limit circuit lockout (depends on model) Safe checks first, then a pro
26 Burner thermal switch open Call a pro
33 Limit circuit fault, a limit or rollout switch is open Safe checks first, then a pro
13.1 Limit circuit lockout, a limit or rollout switch stayed open Safe checks first, then a pro
26.1 Burner thermal switch open, permanent lockout Call a pro
26.2 Burner thermal switch open, permanent lockout Call a pro
32.1 Main pressure switch (LPS) open Safe checks first, then a pro
32.2 Low pressure switch open Safe checks first, then a pro
33.1 Limit circuit switch open, blower running to cool the furnace Safe checks first, then a pro
34.1 Ignition fault, burners did not light in 4 trials Safe checks first, then a pro
34.2 Flame lost before the heating blower started Safe checks first, then a pro
34.3 Flame lost after the heating blower started Safe checks first, then a pro

See all overheat codes on gas furnaces across brands.