Test generator automatic transfer switch (ATS)
Why it matters
Most standby generator outage failures are caused by a failed ATS, not the engine. Whole-house owners almost never test it, so failures go undetected until an actual blackout.
Stop forgetting to do this.
Hearth generates a personalized maintenance schedule so you never miss another test generator automatic transfer switch (ats).
How to do it
- 1
Locate the ATS in or near the main electrical panel (typically a black or gray box with three positions: Off/Auto/Test).
- 2
Consult the ATS manufacturer manual (Generac, Kohler, Briggs & Stratton) for specific test procedure.
- 3
Ensure the generator fuel tank is at least half full and the unit is parked outside.
- 4
Switch the ATS from 'Auto' to 'Test' position and listen for generator to start.
- 5
Wait 10–15 seconds for generator to stabilize and produce full power.
- 6
Verify that lights brighten and appliances (fridge, furnace) switch to generator supply.
- 7
Switch ATS back to 'Auto' position and allow generator to cool for 5 minutes before stopping.