Amana AMVM970803BN Error Code E15: Return Air Temperature Sensor Open (External)
What Does Code E15 Mean?
Code E15 on the Amana AMVM970803BN means the external return air temperature sensor circuit is open. The temperature reading from this sensor will not appear in the CoolCloud HVAC App, but the furnace itself continues to operate and heat your home — this is a monitoring fault, not a shutdown.
The AMVM970803BN uses these temperature sensors to feed the CoolCloud app comfort and diagnostic features rather than to run basic heating. An open circuit usually means the sensor probe is not fully plugged in, its connector is poorly crimped, or the probe itself has failed (it should read about 10k ohms at 77°F). The furnace keeps heating; only the return-air data is lost.
This code belongs to the temperature-sensor family on this board: E15/E16 are the external return-air sensor (open/short), E17/E18 are the external supply-air sensor (open/short), and E19/E1A are the onboard return-air sensor (unplugged/short). They are grouped together because each simply removes one temperature reading from the app while heating continues.
What You'll Notice
- The furnace heats normally but the return-air temperature is blank in the CoolCloud app
- The display shows E15
- The fault may follow recent service where the sensor was disturbed
- No change in actual heating performance
Common Causes
How This Is Diagnosed
A technician verifies the external return-air sensor probe is fully seated and its connector is properly crimped, then measures the probe's resistance, expecting roughly 10k ohms at 77°F. An out-of-range reading condemns the probe.
If the wiring and probe test good but the code remains, the PCB connection is checked. This is a low-priority monitoring fault, so it does not stop the furnace from heating.
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 return-air reading stays missing in the CoolCloud app after a power cycle
- You want the app's comfort and diagnostic features fully restored
- E15 appears alongside other sensor codes suggesting a wiring problem
Frequently Asked Questions
Will E15 stop my furnace from heating?
No. E15 only affects the return-air reading shown in the CoolCloud app. The furnace continues to heat normally; it is a low-severity monitoring fault.
Do I need to fix E15 right away?
It is not urgent since heating is unaffected, but restoring the sensor gives the CoolCloud app full data. Have it checked at your next service visit if it does not clear on a power cycle.
✓ Verified against manufacturer service manual — March 2026