Amana AMVM970803BN Error Code E1A: Onboard Return Air Temperature Sensor Shorted
What Does Code E1A Mean?
Error code E1A on the Amana AMVM970803BN indicates the onboard return air temperature sensor — component R311 on the control PCB — has a short circuit. This sensor is soldered directly onto the board, so the short is either within the component itself, caused by a foreign object on the PCB creating an unintended conductive path, or indicative of PCB damage. The onboard return air temperature will not appear in the CoolCloud App, but the furnace should continue to operate.
A short on the onboard sensor is more unusual than an open circuit fault, and the manual specifically identifies foreign objects on the PCB as a potential cause — dust, metallic debris, or conductive contamination bridging the sensor terminals can create a short-to-ground condition at R311. The initial troubleshooting step of power cycling allows up to 90 seconds for the control to re-scan its onboard sensors, which may clear a transient detection error.
If power cycling does not resolve E1A, a technician should open the furnace and carefully inspect the PCB surface around the R311 component for any foreign objects, metallic particles, moisture residue, or signs of PCB damage. If a foreign object is the cause, it can sometimes be carefully removed. However, if the component or the PCB traces are damaged, the PCB must be replaced.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Onboard sensor component failure | Most common | ✗ Call a pro → |
| Foreign objects on PCB causing short at sensor R311 | Common | ✗ Call a pro → |
| Faulty PCB | Common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- E1A persists after power cycling and waiting 90 seconds — a technician must inspect the PCB around the R311 onboard sensor for foreign objects or damage
- If foreign objects are found on the PCB, they must be carefully removed by a technician to avoid further damage
- If the onboard sensor component or PCB traces are damaged, the PCB requires replacement by a qualified technician
✓ Verified against manufacturer service manual — March 2026