Amana AMVM970803BN Error Code EE8: High Stage Pressure Switch Closed at Start
What Does Code EE8 Mean?
Error code EE8 on the Amana AMVM970803BN means the high stage pressure switch circuit is already in the closed (activated) position at the start of a heating cycle, before the induced draft blower has operated at high speed. The furnace can still ignite and run on low stage, but it cannot transition to high-stage heating.
Under normal operation, the high stage pressure switch should be open at startup and only close when the inducer is operating at its high-speed setting and creating sufficient negative pressure for high-fire operation. Finding it pre-closed tells the control module that either the switch contacts are stuck in the closed position due to mechanical failure, or a short circuit in the high stage pressure switch wiring is creating a false closed signal.
A technician must determine whether the high stage pressure switch has mechanically failed in the closed position or whether the wiring circuit has a short. A stuck high-stage switch must be replaced with the correct replacement part. If the wiring has a short, the fault location must be found and the damaged section repaired. Because the furnace can still run on low stage, this fault does not stop all heating, but high-stage capacity is unavailable until repaired.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| High stage pressure switch contacts stuck closed | Most common | ✗ Call a pro → |
| Short in pressure switch circuit wiring | Common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- EE8 displays — a technician must diagnose whether the high stage pressure switch has failed closed or if the circuit wiring has a short
- A high stage pressure switch stuck in the closed position must be replaced with the correct replacement part
- Repairing a shorted pressure switch circuit requires professional wiring diagnosis
✓ Verified against manufacturer service manual — March 2026