Common Home Standby Generator Problems
In This Guide
A home standby generator is meant to be the reliable one, wired permanently into the house, testing itself weekly, and starting automatically the moment the power fails. When it does not, the causes are different from a portable unit's, because a standby generator is as much an electrical installation as an engine. Here are the common home standby generator problems and what lies behind each.
Why Standby Problems Are Different
A portable generator is an engine you start by hand. A standby generator is an engine wired into your home through a transfer switch, watched over by a controller, started automatically by a battery, and run occasionally by a self-test. That means more can go wrong on the electrical and control side, and much of the diagnosis is electrical.
Problem 1: Doesn't Start During an Outage
The one that matters most, and the one you discover at the worst moment. Causes include a dead starting battery, which is the single most common, a fuel supply problem, a controller fault, or the unit being left in the wrong mode after service.
This is exactly why standby generators run a weekly self-test, and why paying attention to that test matters.
Problem 2: The Battery Is Dead
The most common single fault on a standby generator. The battery has to crank the engine automatically, and batteries degrade over a few years. A standby generator with a dead battery simply cannot start itself, however healthy the engine is.
Problem 3: Transfer Switch Faults
The transfer switch is what disconnects the home from the grid and connects it to the generator. If it fails, the generator can run perfectly while the house stays dark, because the power is not being switched over.
Transfer switch problems are firmly professional territory, as they sit at the junction between mains power and the generator.
Problem 4: Error Codes and Warning Lights
Modern standby units have controllers that display fault codes. Common ones point to low oil pressure, low battery, overcrank (it tried to start and failed), overspeed, or a sensor fault.
The code narrows the diagnosis considerably. Note it down before calling a technician, as it tells them where to look.
Problem 5: Runs But No Power to the House
If the generator starts and runs but the house has no power, suspect the transfer switch or a tripped main breaker on the generator rather than the engine. The same loss-of-residual-magnetism issue that affects portables is less common on standby units but not impossible.
Problem 6: Fails the Weekly Self-Test
Standby generators exercise themselves weekly. If you notice it has stopped running its test, or it starts but runs poorly during it, treat that as an early warning and investigate before a real outage arrives. The self-test exists precisely to catch problems early.
Rather Have a Real Technician Handle It?
A Wildwood technician comes to your home, diagnoses the generator on site, and gets it running, usually in about an hour. More than 10,000 repairs completed since 2019, with flat rates quoted before we arrive so there are no surprises. When you need power back, you need it back now.