Amana AMVM970803BN Error Code E19: Onboard Return Air Temperature Sensor Unplugged

What Does Code E19 Mean?

Error code E19 on the Amana AMVM970803BN indicates the onboard return air temperature sensor — a component mounted directly on the control PCB, identified as resistor R311 — is detected as unplugged. Unlike the external sensor errors (E15, E16), this sensor is integral to the circuit board, so it cannot be physically unplugged by a user. The furnace should continue to operate, but the onboard return air temperature will not appear in the CoolCloud App.

Because the sensor is onboard the PCB, the most likely causes are electrical or mechanical damage to the R311 component on the board, a solder joint failure, or a control module initialization issue. The manual recommends power cycling the furnace and allowing up to 90 seconds for the control to detect its onboard sensors before concluding there is a hardware problem — this can sometimes clear a transient fault at startup.

If power cycling does not resolve E19, a technician should visually inspect the PCB for any visible damage to the R311 sensor component, including discoloration, corrosion, or physical damage. Since this is a component on the PCB itself, the remedy is typically PCB replacement.

Common Causes

When to Call a Professional

Contact a licensed HVAC technician if:

• E19 persists after power cycling the furnace and waiting 90 seconds — a technician must inspect the onboard sensor R311 on the PCB
• If the PCB shows visible electrical or mechanical damage near the R311 component, the PCB must be replaced
• PCB replacement on this modulating furnace should only be performed by a qualified HVAC technician

✓ Verified against manufacturer service manual — March 2026