What It Means
- CBX40UHV: Relay Y2 failure. AHC relay activated, but not respond back .
- CBK48MVT: The Y2 relay on the air-handler has failed. Either the pilot relay contacts did not close or the relay coil did not energize.

Split & Multi-Split
E348 means different things on different Split & Multi-Split models. Enter your model number to see only your reading, or find your model below.
Models: CBX40UHV
Air handler (indoor)
This manual entry does not list further causes or actions.
Relay Y2 failure. AHC relay activated, but not respond back .
Models: CBK48MVT
Operation stopped. Y2 relay failed. Pilot relay contacts did not close or the relay coil did not energize. The indoor unit cannot verify that the relay is closed. The alarm clears after a reset and Y2 input sensed.
The Y2 relay on the air-handler has fai- led. Either the pilot relay contacts did not close or the relay coil did not energize.
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