6 red flashes
Pressure switch opened four times during the heat call
This code typically points to
- Weak inducer
- Blocked vent
- Faulty pressure switch
Next checks to confirm
- Verify inducer performance under load
- Inspect vent and switch
- Check for intermittent draft loss
Escalation
Pattern indicates marginal draft or switch.
Reset behavior
1-hour lockout then restart.
Urgent
Fix now