Bryant 315AAV Error Code 25: Invalid Model Selection or Setup Error
What Does Code 25 Mean?
Status code 25 on the Bryant 315AAV is an invalid model selection or setup error. This control identifies the specific furnace model it is installed in through a model plug (PL4) and a bank of setup switches (SW1). Code 25 means the control cannot read a valid model configuration, or a setup switch is in a position that conflicts with a thermostat call.
Bryant's data explains that if the code flashes four times on power-up, the control is defaulting to a model selection stored in memory. Specific triggers include: model plug PL4 missing with no valid model stored in permanent memory; PL4 installed but not a valid plug for a service-replacement control; or a thermostat call present while SW1-1 is ON, while SW1-6 is ON, or with both ON. In short, the board's identity or its setup switches do not match the furnace.
Because it is a setup issue rather than a combustion or airflow hazard, code 25 is a low-severity fault — but it still stops correct operation. It most often appears right after a control board is replaced and the model plug or switches were not transferred or set correctly. Verifying the model plug and SW1 switch positions against the installation instructions is a technician task.
What You'll Notice
- The furnace was just serviced or had its control board replaced and now will not run correctly
- The status LED flashes two short then five long flashes (and may flash four times on power-up)
- The furnace does not respond normally to a thermostat call because setup switches conflict
- The problem appeared immediately after board or model-plug work, not gradually over time
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Model plug PL4 is missing or incorrect | Most common | ✗ Call a pro → |
| Setup switches SW1-1 or SW1-6 improperly positioned | Common | ✗ Call a pro → |
How This Is Diagnosed
A technician checks the control's identity and setup: confirming the correct model plug PL4 is installed and valid for this furnace, then verifying the SW1 setup switch positions — particularly SW1-1 and SW1-6 — against the model's installation instructions. If a replacement board was installed, they confirm the model plug was transferred from the original board or the correct plug was used, and that no switch is left in a conflicting position during a thermostat call.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The code appeared right after a control-board replacement or other service
- The furnace will not operate normally until the model plug and switches are verified
- You suspect the model plug PL4 is missing, wrong, or was not transferred to a new board
- Any change to setup switches or the model plug, which requires the installation instructions and a technician
Frequently Asked Questions
Why did my Bryant 315AAV show code 25 right after a repair?
Code 25 usually means a replacement control board is missing the correct model plug (PL4) or its setup switches were not set right. Transferring the model plug and confirming SW1 positions typically resolves it.
Is code 25 dangerous?
It is a low-severity configuration error, not a combustion or airflow hazard. It still prevents correct operation, so it needs to be corrected, but it is not an immediate safety emergency.
Can I set the switches myself?
No. Setting SW1 and verifying the model plug requires matching them to the model's installation instructions; incorrect settings can cause improper operation, so this is a technician task.
Sources
✓ Verified against manufacturer service manual — March 2026