E2
Low-stage pressure switch circuit is not closed
This code typically points to
- Pressure-switch hose blocked/pinched/improperly connected
- Blocked flue or inlet air pipe
- Blocked drain system
- Weak induced-draft blower
- Incorrect pressure-switch set point or malfunctioning contacts
- Loose/improperly connected wiring
Next checks to confirm
- Inspect pressure-switch hose
- Inspect flue and/or inlet air piping for blockage/length/elbows/termination
- Check drain system
- Check induced-draft blower performance
- Correct pressure-switch set point/contact issue
- Tighten/correct wiring
Escalation
Induced-draft blower runs continuously with no further furnace operation
Reset behavior
Clears after pressure-switch proving is restored.
Urgent
Fix now