Lennox TUA*S(N,L)(A,S)F Error Codes

Unit heater · Ducted Heating

• 2 Flashes System lockout - failed to detect or sustain flame Current signal at FLAME terminal <0.6…
• 3 Flashes Combustion air inducer proving switch failed closed before CAB is energized or failed…
• 4 Flashes High limit or rollout switch open
• 5 Flashes Flame sensed and gas valve not energized
• Fast Flash Normal Operation - Call for heat Current signal at FLAME terminal 0.6 to 1.0 microamps
• Slow Flash Normal Operation - No call for heat
• Steady Off Loss of Power
• Steady On Ignition control failure

Reference only. Confirm against the manual for your exact model. Data release 105f66ecb9e96e5dc473025d.