Controller displays E08 and the generator will not start in AUTO mode when utility power fails.

Safety first: Turn OFF the generator and lock out/tag out the main utility breaker. Only qualified persons should work inside the transfer switch.

• Check controller settings: Verify that AUTO mode is enabled and that utility sensing parameters are correctly configured according to the DuroStar installation manual.
• Inspect sense wiring: Locate the utility sense terminals on the generator control board and ATS. Check for loose, broken, or corroded wires. Tighten terminals and repair any damaged conductors.
• Check ATS control fuse: Open the ATS enclosure and locate the low‑voltage control fuse. Test it with a multimeter and replace if open with the same rating.
• Verify correct wiring: Compare the wiring between the generator and ATS to the DuroStar wiring diagram. Correct any mis‑wired terminals, especially sense and start/stop signal wires.
• Test ATS operation: Simulate a power failure under controlled conditions and observe whether the ATS sends a start signal to the generator. If not, the ATS control board may be defective and require replacement.
• Controller reset: After repairs, clear E08 and retest automatic start. If the fault returns, contact a technician to evaluate the ATS and generator control board communication circuits.