Alert 348 — Relay Y2 Failure

What does 348 mean?

The system has detected a failure with the Y2 relay, which is responsible for sending a compressor demand. This means the indoor control cannot relay the demand to the outdoor unit.

• Possible Y2 relay or stage 2 failure.
• Furnace pilot relay contacts did not close or the relay coil did not energize.
• No input back to the furnace or air handler control.

Click steps to track your progress.

1. 1

   The system will automatically clear this alert when the issue is no longer detected.

2. 2

   Check for a possible Y2 relay or stage 2 failure.

3. 3

   Verify that the furnace pilot relay contacts are closing and the relay coil is energizing.

4. 4

   Ensure there is input back to the furnace or air handler control.