Carrier · Status code
Carrier 59TP6C status code 25: control program and configuration faults
Major code 25 covers control-program and configuration faults. The 59TP6C control must run the model program number printed on the rating plate; when that program is missing, corrupted, wrong for the furnace, or the installer settings were damaged, the control reports one of the seven sub-codes and may stop heating or fall back to defaults.
On the control
- Code
- 25
- Minor
- 25.1 · 25.2 · 25.3 · 25.4 · 25.5 · 25.6 · 25.7
- Door LED
- 2 short flashes then 5 long
- Controller
- 59TP6C integrated furnace control with 3-digit LCD display and door LED
- Applies to
- Carrier Performance 96 (59TP6C)
- Manual
- 59TP6C-01SI REV A
What each minor code says, verbatim
| Display | Manufacturer wording |
|---|---|
| 25.1 | No program info in micro, no heating operation. |
| 25.2 | Corrupted program file, reprogram control using service app or super plug (supplied separately), no heating operation. |
| 25.3 | Twinned units are not identical, program #'s do not match. Ensure furnaces are identical (same program #) when twinning. Main unit will not operate in heating. |
| 25.4 | Main program invalid, using backup program to operate. Reprogram control to correct issue. Control still operates normally. |
| 25.5 | Installer settings corrupted. Try reselecting installer settings, or reprogram control. Control will operate using default installer settings. |
| 25.6 | Wrong program for control used - reprogram control so program matches control used. No heating operation. |
| 25.7 | If program in furnace control is missing, not recognized, or corrupted. Reprogram control with correct program # as listed on the rating plate. Replace control if issue remains. |
A code is a condition, not a diagnosis
Program faults usually follow control-board replacement, a failed reprogramming attempt, or power loss mid-update. Sub-codes 25.3 and 25.6 also appear when two furnaces are twinned without matching programs. The rating plate's program number is the reference for the correct program; the code does not identify which part failed if reprogramming does not clear it.
Which furnaces this applies to
Documented for Carrier 59TP6C furnaces (all nine sizes) in installation instructions 59TP6C-01SI REV A, edition 06/23. The manual warns against programming the control board with a model program number different from the rating plate, and explains the two approved reprogramming methods (the supported mobile app over NFC, or the correct super plug).
Scope: Carrier 59TP6C Performance 96 furnaces with the on-board 3-digit display control. Not sure which control you have? Send us the full model number from the rating plate.
Safe things to look at first
- Read the full code on the control display through the door, including any minor digit (for example 33.2), and write it down.
- Look, without touching, for obvious conditions you can report: snow or ice at the vent terminations, water on the floor, a loaded filter, a condensate pump that is full or off.
- Note whether the furnace still heats at all, and how long it runs before the code returns.
- Read the model program number from the rating plate and note it for the technician.
- Note when the fault first appeared, for example after a control-board change or a power outage.
Do not
- Do not bypass or jumper the door switch, limit switches, rollout switches or pressure switches.
- Do not open the burner compartment, disconnect tubing, or adjust the gas valve or gas pressure.
- Do not keep cycling power to force the furnace to relight; repeated resets hide the fault and can allow unburned gas to build up after ignition failures. If the code returns, stop and call.
Homeowner-safe checks (look and read only)
- Read the model program number from the rating plate
- Note when the fault first appeared, such as after a control change
When to call a technician
- If the furnace is not heating
- If reprogramming does not clear the fault
Also documented on the same controller family: Carrier Performance 97 (59TP7A).
What a technician does
- A technician verifies the control's stored program number against the rating plate and reprograms the control using Carrier's approved method (NFC service app or the correct super plug).
- If the program will not load or the fault returns, the control is replaced and programmed with the rating-plate program.
Related components and symptoms
Questions people ask
My furnace lost its program after a power outage. Is that common?
Program faults are not caused by ordinary power outages; they usually follow a control-board change or a failed update. The program is reloaded from the rating plate number.
What is a super plug?
A super plug is a Carrier service accessory pre-loaded with a model program. It is used to copy the correct program onto a replacement control board when the mobile app is not used.
Seeing code 25 on your Carrier?
Tell us the full code, the model number and whether the furnace still heats on low. BC Wide prioritizes no-heat calls across Greater Vancouver.