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
- E08 — Flame current low but still usable
- E2.1 — Retry exceeded — flame never sensed, one hour lockout
All codes for this manufacturer
Trane and American Standard furnace flash codes — every code, with what differs between models.
What the fix costs
The likely repair is the repair guide's cheapest line: flame sensor cleaning at $80–200, the ten-minute classic. The qualifier specific to E2.2 is persistence — a furnace that reached ten recycles has usually been degrading for weeks, and if a cleaning has already been done and the code returned, paying for a second one is paying twice for the wrong diagnosis. The second visit belongs on the electrical side: ground and polarity checks are diagnostic work, $75–150, and they sit upstream of every sensing component. More codes like this across brands: flame sensor codes.
DIY or call a pro
The furnace retries on its own after the hour, which removes the one tempting intervention. What a homeowner adds is the observation the code cannot store: how long each run lasts before the flame drops. A consistent few seconds points at sensing; minutes of normal running before shutdown points elsewhere, and saying which on the phone changes what the technician brings. Check the history for E08 too — its presence dates the decline. The burner compartment itself stays shut: the rod, its insulator and its circuit are the parts that decide whether gas keeps flowing, and they are brittle in inexperienced hands.
The same fault on other brands
Trane splitting recycles from retries is the uncommon choice. Its own flash-code system bundles both into two flashes, and the Allied -02 control does the same in its five-flash Watchguard code, which counts retries and recycles together. The ten-recycle allowance against three retries is the detail worth keeping: this control is far more tolerant of losing a proven flame than of failing to prove one, because only the second leaves unburnt gas behind.
What this looks like
From the outside, this usually shows up as the burner lights and then drops out a few seconds later — that walkthrough covers what to check in order, and when it stops being a homeowner job.
This can also show up as the pilot light will not stay lit — that page walks through thermocouple, draft and gas causes in order.