Error Code EC1
Low

Amana AMVC960803BN Error Code EC1: Network Communication Alarm

TL;DR
The furnace control board has lost communication with the ComfortNet thermostat or network. Basic heating may still work in fallback mode, but smart thermostat features are unavailable until communication is restored.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code EC1 Mean?

Error code EC1 on the Amana AMVC960803BN indicates that the integrated control module has lost communication with the ComfortNet network. ComfortNet is Amana's proprietary communication protocol used between compatible thermostats, furnaces, and air conditioning equipment to enable smart system control, diagnostics, and coordinated operation.

When ComfortNet communication is lost, the furnace may continue to operate in a conventional thermostat fallback mode — responding to basic heat/cool calls from the R and W terminals — but advanced features such as variable-speed blower control through the thermostat, remote diagnostics, and coordinated system operation will not function. The type of fault and the severity of the impact depend on the system configuration.

A technician will check the ComfortNet wiring between the thermostat and the furnace, verify that the thermostat is powered and operating, inspect for any damaged or loose wiring at the communication terminals, and confirm that the ComfortNet network is properly configured. In some cases, the furnace control board or the ComfortNet thermostat may need replacement.

Common Causes

Cause Likelihood DIY?
Lost communication with ComfortNet thermostat or network Most common ✗ Call a pro →
Wiring issue between furnace and thermostat Common ✗ Call a pro →

When to Call a Professional

Contact a licensed HVAC technician if:

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Sources

  1. Service Instructions - 34.5" Chassis ACVC96*BA/AMVC96*BA/GCVC96*BA/GMVC96*BA Gas Furnaces
  2. Amana AMVC960803BN Product Page

✓ Verified against manufacturer service manual — March 2026