Heil G80CTL furnace code 25: Model data or setup error
Professional repair
What does 2 short and 5 long amber flashes mean on a Heil G80CTL Series A furnace? If this shows four times at power-up and stops, the model plug is missing but the control is using stored model data. If it keeps repeating, the model data, plug, switch settings or twinning setup are invalid.
Before you touch anything: the six signs that mean stop troubleshooting and call a pro →
Checking the model plug, stored model data and SW1 settings against the furnace label is technician work. Owners should not change switch settings, and the pattern needs telling apart from code 7.
Possible causes
- Model plug missing or not matching the furnace TECH
- SW1-1 or SW1-6 setting conflicts with the configuration TECH
- Twinned with a furnace of a different model TECH
Parts for this code
No model-verified part number is listed here. Have the fault diagnosed and the correct part matched to your furnace before ordering.
Questions about this code
What does 2 short and 5 long amber flashes mean on a Heil G80CTL Series A furnace?
If this shows four times at power-up and stops, the model plug is missing but the control is using stored model data. If it keeps repeating, the model data, plug, switch settings or twinning setup are invalid.
How do I fix Heil G80CTL furnace code 25?
Note whether the pattern stopped after four rounds at power-up or keeps repeating, then tell the technician. Keep counting short and long groups separately; adding them gives seven and points to the wrong code. Do not adjust DIP switches.
How much does it cost to fix Heil G80CTL furnace code 25?
Expect diagnosis and setup labor. A missing or wrong model plug must be replaced with one matching the furnace model, and twinned systems take extra time to check.
Applies to
Heil G80CTL Series A
Different Heil generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Verified against F80CTL & G80CTL (Series A): Installation, Start-Up, Operating and Service and Maintenance Instructions, p.34
Verified against F80CTL & G80CTL (Series A): Installation, Start-Up, Operating and Service and Maintenance Instructions, p.38
Verified against F80CTL & G80CTL (Series A): Installation, Start-Up, Operating and Service and Maintenance Instructions, p.47
Last verified 2026-10-07 · page updated 2026-10-07 · how we verify
Related Heil furnace codes
These codes use the same heil g80ctl series a amber led control system.