Fault Code Lookup

HVAC Sales Master
Green + Red continuous
Fuse open or internal control failure
This code typically points to
  • Open fuse
  • Internal control failure

Next checks to confirm
  1. Check 24V fuse
  2. Inspect wiring for shorts
  3. Replace control if fuse tests good and fault persists

Escalation
Control failure / no heat
Reset behavior
Not replayed as a solid-red fault in last-fault recovery.
Urgent
Fix now
Source
Trane 18-CD26D1-13 Installer's Guide, p.43