Amana AMVC960803BN Error Code EC3: Bluetooth Module Network Communication Alarm
What Does Code EC3 Mean?
The communicating Amana AMVC960803BN can include a Bluetooth module that lets a phone app connect to the furnace for setup and status. That module attaches to the integrated control module and communicates with it over the system's low-voltage data link. Code EC3 is raised when the furnace control can no longer talk to that Bluetooth module.
This is the most benign of the communication codes on this board, and Amana rates it low severity. EC3 is a comfort-feature alarm only: it takes away the phone-app connection but does not touch the heating cycle. The furnace continues to run and stage exactly as it normally would, so many homeowners only notice EC3 because the app stops connecting.
Among the siblings, EC3 is strictly the Bluetooth module link. That is different from EC1, the furnace-to-ComfortNet-thermostat/network link, and EC2, the external E-Module link — both of which can affect coordinated system features rather than just a phone app. It is also different from EC4 and EC5, which report an expected external equipment relay module (EC4) or accessory relay module (EC5) that was not detected. Because EC3 only governs the app connection, restoring it is about convenience, not keeping the house warm.
EC3 usually traces back to a Bluetooth module that has come loose or failed, or a disturbed connection between it and the furnace control.
What You'll Notice
- The phone app will not connect to the furnace or repeatedly drops the connection
- The furnace continues to heat and stage normally with no change in comfort
- The integrated control module's 7-segment display shows EC3
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Bluetooth module disconnected or failed | Most common | ✗ Call a pro → |
| Wiring issue between control and Bluetooth module | Common | ✗ Call a pro → |
How This Is Diagnosed
Because heating is unaffected, diagnosis is limited to the Bluetooth feature. A technician confirms the Bluetooth module is present, seated, and powered, then inspects the connection between the module and the integrated control module for a loose or damaged link.
If the module is properly connected but communication still cannot be established, the fault is isolated to the Bluetooth module or, less commonly, the furnace control. This is diagnostic context only and is optional to pursue, since the furnace heats normally without the app connection.
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:
- You rely on the phone-app connection and EC3 remains after the Bluetooth module has been reseated and checked
- EC3 appeared alongside other ComfortNet communication codes, which may point to a shared wiring or control issue
Frequently Asked Questions
Will my furnace still heat with an EC3 code?
Yes. EC3 only affects the Bluetooth phone-app connection. Your heating continues to run and stage completely normally.
Do I need to fix EC3 right away?
No. It is a convenience-feature alarm, not a safety or heating fault, so it can be addressed at your convenience if you want the app connection back.
Why does only my app stop working with EC3?
The Bluetooth module exists just to bridge the app to the furnace. When the control loses communication with it, the app connection drops while the heating cycle is unaffected.
Sources
✓ Verified against manufacturer service manual — March 2026