Bryant | Default

Error Code 78

Troubleshooting guide for the Bryant Default system fault 78.

Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.

System Diagnosis

High Stage Did Not Start 3 times. For 3 consecutive high stage starts, the specified start voltage at VS terminal was not achieved and start relay was de-energized. High stage locked out for 30 minutes.

Potential Causes & Solutions

Diagnose with Confidence

Use the ACLogics AI assistant to walk through this error code step-by-step.

Included in Diagnosis Workflow

1

Ask

Upload nameplate & symptoms

2

Diagnose

AI identifies error 78

3

Report

Generate professional PDF