Direct answer
On the covered Kohler standby generator, ATS PhaseRot means warning. Transfer-switch phase rotation does not match, so the ATS will not transfer. First, do not attempt to force a transfer.
Definition versus diagnosis
The display names a detected condition—not an automatically failed part.
What this covers
- Kohler standby generator covered by the cited source
- Displayed code or documented alias: ATS PhaseRot
- The exact operating state described by the manufacturer
What it does not cover
- ×Another product type or original-manufacturer platform
- ×A visually similar but different code
- ×Internal live electrical, sealed-system, gas, battery-cell or control-board repair
Match every character and the exact product
ReversiblePhotograph the complete display and product label. This record covers ATS PhaseRot on Kohler residential standby generator sets using the RDC2/DC2 controller; the displayed fault text, warning/shutdown behaviour and available customer checks vary by model and controller firmware. Confirm against the operation manual for the exact model.
Preserve the failure state
ReversibleDo not attempt to force a transfer. Record the operating stage, recent change and what still works before clearing the message.
Correct only the documented fault domain
ReversibleKohler directs correcting the ATS connection using the ATS installation manual, wiring diagrams and the labels on the transfer switch. Do not borrow a reset or meaning from a similar code, product or model year.
Verify once, then respect the service boundary
ReversibleRepeat only the shortest safe action that reaches the original stage. If ATS PhaseRot returns, stop repeated resets and use model-specific manufacturer support.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Exact questions
Common follow-ups
What does ATS PhaseRot mean on a Kohler standby generator?+
Warning. Transfer-switch phase rotation does not match, so the ATS will not transfer.
Can I reset ATS PhaseRot without fixing the cause?+
A reset may hide the display temporarily but does not correct the documented fault. Record the code and complete only the safe checks first.
Why is the complete model number required?+
Manufacturers reuse characters across platforms. The model number determines which official table, controls and service boundary apply.
When should I stop?+
Stop for smoke, arcing, burning odor, uncontrolled water, gas odor, battery swelling, extreme heat or any condition the manufacturer directs to professional service.
Answer for the exact device and software version shown above.