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Carrier Error Code 25: Invalid model selection or setup error (Furnace)

Updated · by Aurora Star Tech Inc.

Carrier error code 25 on a furnace means: Invalid model selection or setup error. It is also called Carrier diagnostic code 25.

Medium severityFurnace59TP6A

Homeowner? What Carrier code 25 means for you

Check, then call Your furnace is reporting: Invalid model selection or setup error. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

Safe things you can check yourself

  • Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
  • Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
  • Make sure the furnace front door or panel is closed properly; many furnaces will not run with the door switch open.
  • Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
  • Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
  • Check that the gas valve next to the furnace is open (handle in line with the pipe). Do not force it.
  • Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Carrier error code 25 mean?

If 25 flashes only 4 times at power-up, model plug PL4 is missing and the control is using the model stored in memory. Flashing continuously indicates a setup error.

Applies to: 59TP6A two-stage variable-speed ECM multipoise condensing gas furnace, all sizes (040-10 to 120-22)

Common causes of Carrier code 25

  • Model plug PL4 missing and no valid model stored (common on replacement controls)
  • Thermostat call with SW1-1 ON
  • Thermostat call with SW1-6 ON

A technician checks these and 3 other possible causes on site before replacing any part.

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Carrier models that use code 25

59TP6A040-1059TP6A040-1259TP6A060-1259TP6A060-1459TP6A080-1659TP6A080-2059TP6A100-2059TP6A120-22

Other Carrier Furnace codes

CodeMeaning
22.1False flame
23Pressure switch did not open
23.1Main pressure switch stuck closed
23.2Secondary pressure switch stuck closed
24Secondary (24 V) fuse open
24.1Fuse fault (24 V)
25.1No program in control
25.2Corrupted program file
25.3Twinned furnaces not identical
25.4Main program invalid, running on backup
25.5Installer settings corrupted
25.6Wrong program for this control

All Carrier Furnace error codes →

Carrier code 25: homeowner questions

What does Carrier code 25 mean?

Invalid model selection or setup error. If 25 flashes only 4 times at power-up, model plug PL4 is missing and the control is using the model stored in memory. Flashing continuously indicates a setup error.

Is it safe to keep using my furnace with code 25?

It depends on the cause. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.

Can I reset Carrier code 25 myself?

You can try one reset (power off for 30 seconds, then on). If Carrier code 25 comes back, the cause is still there and a licensed technician should check it.

Who can fix Carrier code 25 near me?

Aurora Star Tech Inc. repairs Carrier furnaces in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Furnace Not Turning On: What to Check · Furnace Blinking Light: What the Flash Codes Mean

Troubleshooting guides

Source: Carrier 59TP6A Installation, Start-up, Operating and Service Instructions, Fig. 66 Troubleshooting Guide (cont.), p.89. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency Furnace Repair

647-657-2977