HVAC Sales Master

Fault Code Lookup

HVAC Sales Master
16 (legacy communicating outdoor)
Communication with User Interface lost on legacy communicating outdoor (24ANB, 25HCB, similar Infinity/Evolution non-inverter communicating ODU families).
This code typically points to
  • ABCD bus wiring fault
  • UI power loss
  • Indoor-outdoor communication break
  • Device on comm bus dragging communications down
Next checks to confirm
  1. Read amber status light on outdoor control board
  2. Verify ABCD communication path from wall control to indoor to outdoor
  3. Check terminations and power to communicating UI
Escalation
No special local-board-only recovery mode documented for these legacy non-inverter outdoor units comparable to inverter platform's emergency communicating mode. Restore comm path.
Reset behavior
Clears when communication is re-established. Not documented as a manual-reset outdoor-board lockout.
Urgent
Fix now
Need deeper detail?
Retrieve the subcode for this platform:
  1. From the main screen, touch Menu
  2. Touch and hold the Service icon for at least 10 seconds until it turns green
  3. Open Service Information
  4. Use View Diagnostics for the most recent fault's top three likely root causes
  5. Use Last 10 System Events for timestamped recent events
  6. Use Run/Fault History for resettable fault counters, cycle counters, and run times
Source
Carrier/Bryant 24ANB communicating outdoor service manual status code table, 25VNA service manual communication-loss section, Sigler NorCal public master fault code list.
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