Alarm 234 (or 225, 8) Exchange sensors flow / return — Supply and return lines are switched

What does Exchange Sensors flow / return 234 mean?

This alarm means the return line is hotter than the flow line, indicating that the supply and return lines, or their sensors, have been incorrectly connected.

• Supply and return lines have been switched.
• Flow and return sensors are incorrectly connected.

Click steps to track your progress.

1. 1

   Check the indoor module/control module display for specific action instructions.

2. 2

   Verify the physical connections of the supply and return lines to ensure they are not reversed.

3. 3

   If comfortable and safe, visually inspect the flow and return sensors to confirm they are attached to the correct pipes.

4. 4

   Contact a qualified technician to verify plumbing and sensor connections.