Armstrong furnace Error code recall: The last ten faults, retained even through a power cut
This control stores the last ten error codes and keeps them when power is shut off. That is unusually generous, and it makes intermittent faults genuinely diagnosable.
Applies to: Allied Air Enterprises A80UH1E and 80G1UHE gas furnaces with the -02 integrated control, sold as Armstrong Air, AirEase, Concord and Ducane.
What it means
Most furnace controls store one fault, or a handful, and lose them the moment power is interrupted. Allied Air documents the opposite: the last ten error codes are stored in memory, including when power is shut off to the unit. That single design choice removes the most common way diagnostic information gets destroyed — someone switching the furnace off and on before anyone reads the display. To recall, press and release the button on the control. The most recent code is shown first, then the LED goes off for three seconds and the next is displayed, and so on. Holding the same button longer than five seconds clears the memory.
Most common causes
- Not applicable — this is a procedure rather than a fault condition.
How to diagnose it
- Press and release the button on the control to begin recall. Do not hold it — holding for more than five seconds erases everything.
- Read the codes in order. Most recent is displayed first, with a three second gap between each.
- Write them down as they appear. Ten codes played in sequence with three second gaps is more than most people can hold in their head.
- Note that a power cut does not clear this history, so it is worth recalling even on a furnace that has been switched off for days.
How to fix it
- Recall the history before anyone resets or clears anything. On this control it is the most valuable diagnostic information available and it takes seconds to read.
- Do not clear the codes to "start fresh". A technician arriving to a cleared memory has lost the pattern that would have explained an intermittent fault.
- The button is on the control board inside the cabinet, so the recall itself is technician work on most installations.
- Give the technician the sequence, not just the most recent code. The order tells them how the fault developed.
Notes
Ten codes surviving a power cut is the most generous fault memory of any furnace control documented on this site. Carrier's red LED boards lose their stored code on any power interruption, and ICP's clears after 72 hours. If you have an Allied Air furnace, the history is almost certainly still there.
Related
- Heartbeat — Control powered, no errors detected
- Reading a furnace fault code — How to find, count, and interpret the diagnostic light
All codes for this manufacturer
Armstrong Air, AirEase, Concord and Ducane furnace codes — every code, with what differs between models.