Amana AMVC960803BN Error Code EEF: Condensate Switch Open
What Does Code EEF Mean?
Error code EEF on the Amana AMVC960803BN means the auxiliary condensate switch (overflow switch) has opened, shutting down the furnace. This switch triggers when the water level in the condensate system gets too high, indicating the drain is not removing water fast enough.
As a high-efficiency condensing furnace, the AMVC960803BN produces condensate (water) as a normal byproduct of combustion. This water collects in a drain pan and flows out through a PVC drain line with a trap. Over time, algae, mineral deposits, and debris can clog the drain line or trap, causing water to back up.
When the condensate switch detects a high water condition, it opens the circuit to prevent water damage and potential safety hazards. The furnace will not operate until the water level drops and the switch resets. In some cases, the issue may also involve a blocked evaporator coil drain pan if the furnace shares drainage with an air conditioning system.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Clogged condensate drain line or trap | Most common | ✗ Call a pro → |
| High water level in evaporator coil drain pan | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- The drain line remains clogged after vacuuming and flushing
- Water is leaking from the furnace onto the floor
- EEF returns within a few hours of clearing the drain
- You are unsure where the condensate drain line runs or terminates
- There is standing water in the evaporator coil drain pan above the furnace
Sources
✓ Verified against manufacturer service manual — March 2026