Amana AMVC960803BN Error Code EE8: High Stage Pressure Switch Stuck Closed
What Does Code EE8 Mean?
At the beginning of a heating cycle on the AMVC960803BN, the high-stage pressure switch contacts should be OPEN, because the inducer has not yet reached high-stage speed and no high-fire draft exists. Code EE8 is set when the control finds that switch circuit already CLOSED at startup — draft it cannot yet be sensing — which the control flags as a high-stage fault.
Because this is a two-stage condensing furnace, each firing rate has its own pressure switch proving safe venting for that stage. EE8 only affects the high stage: the induced-draft blower runs, the low-stage pressure switch works normally, and the furnace continues to heat on low stage. You still get heat, just at reduced capacity — it may never reach full output on the coldest days. This is different from EE1 (Low Stage Pressure Switch Stuck Closed), where the low-stage switch is stuck and the furnace cannot start at all.
The usual causes are high-stage pressure-switch contacts that are physically sticking closed or a short in the high-stage pressure-switch wiring that keeps the circuit made. EE8 is the stuck-closed partner of EE9 (High Stage Pressure Switch Open), where the same high-stage switch instead fails to close when high-fire is demanded.
What You'll Notice
- The furnace heats but never reaches full output, struggling on the coldest days
- It runs only on low stage and does not step up to high fire
- The dual 7-segment display reads EE8
- Longer run times and rooms that are slower to reach the set temperature
- Otherwise normal startup — the inducer, igniter, and burners all light on low stage
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| High stage pressure switch contacts sticking closed | Most common | ✗ Call a pro → |
| Short in high stage pressure switch wiring | Common | ✗ Call a pro → |
How This Is Diagnosed
A technician verifies the high-stage switch is genuinely stuck rather than mis-wired. With the inducer off and no call for heat, the high-stage pressure switch should read open; they meter across its contacts and check the harness back to the control board for a short that would keep the circuit closed.
If the wiring checks out, the switch is evaluated for contacts sticking closed and compared against its rated set point. A switch that will not open at rest is replaced with the correct Amana part; a wiring short is repaired. Because this involves the combustion venting-safety circuit, it is technician work even though the furnace is still producing some heat.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The furnace only runs on low heat and will not step up, with EE8 on the display
- Heating capacity is noticeably reduced during cold weather
- EE8 returns after a power reset
- The code appears together with EE9 or the low-stage codes EE1/EE2
Frequently Asked Questions
Is it safe to keep running the furnace with EE8?
The furnace continues to heat on low stage, and the safety system has correctly disabled only the high stage. It is still best to have the switch diagnosed soon, since a stuck pressure switch defeats a venting-safety check for that stage.
Why does my furnace still make heat with EE8 but not with EE1?
EE8 is the high-stage switch, so only high-fire is blocked and low-stage heating continues. EE1 is the low-stage switch the furnace needs to start, so it results in no heat at all.
Could low heat output on cold days just be EE8?
It can be — a furnace stuck on low stage will feel underpowered when it is very cold outside. Checking the display for EE8 (or the related EE9) is the quickest way to confirm a high-stage pressure-switch fault.
Sources
✓ Verified against manufacturer service manual — March 2026