Trane furnace E2.2: Recycles exceeded — flame sensed then lost, one hour lockout
E2.2 means the furnace lit successfully and then lost the flame, ten times, before locking out for an hour. The allowance is far larger than the three retries Trane permits for failing to light.
Applies to: Trane and American Standard S9V2 two-stage condensing variable speed gas furnaces with a seven-segment integrated furnace control display, per Installer's Guide 18-CE01D1-1E-EN.
What it means
The gap between the two numbers is the interesting part. Trane allows three attempts at lighting before locking out, but ten recycles — ten occasions where flame was proven and then lost. That asymmetry is deliberate: a furnace that fails to light is potentially putting gas into a chamber with no ignition, while a furnace that lights and loses flame has at least burned what it admitted. Ten recycles also means that by the time this code appears, the furnace has been misbehaving for a while. It is not a sudden failure. Someone reporting this has usually had a furnace that seemed to work but kept short-cycling for days or weeks first.
Most common causes
- A flame sensor coated in oxide, which is the most common cause by a wide margin.
- A bad ground or reversed line polarity, both of which weaken the flame signal without any visible fault.
- A cracked or mispositioned flame sensor, so the flame does not fully envelop the rod.
- Burners partially blocked, giving an unstable flame.
- Marginal gas pressure producing a flame that lifts or wavers.
How to diagnose it
- Note how long the furnace runs before shutting down — a consistent few seconds points at flame sensing rather than at anything thermal.
- Note when the flame sensor was last cleaned. This is routine maintenance rather than a defect.
- Ask for the flame current reading at the FP pads before and after any cleaning, since this control makes that measurable.
- Check the Last 6 Faults menu for a stored E08, which is the early warning for this condition.
How to fix it
- Cleaning or replacing the flame sensor is the usual repair and is technician work in the burner compartment.
- Ground and line polarity should be confirmed first, particularly if a cleaning has already been tried and did not last.
- The one hour lockout clears itself, so the furnace will retry without intervention.
Notes
If E08 appears in the fault history before E2.2, the furnace warned that the flame current was getting weak before it started shutting down. That is the moment the repair was cheapest.
Related
All codes for this manufacturer
Trane and American Standard furnace flash codes — every code, with what differs between models.