Generator repair

When to call

Call for service when the controller or app shows a warning or fault, when the weekly exercise stops, or when the generator starts and then quits. Other warning signs include rough running, knocking, smoke, a fuel smell, or a generator that runs without powering the house. That last one often points to the transfer switch or a tripped breaker rather than the engine.

A unit that passes its weekly exercise can still struggle under a real load, so do not ignore a fault just because the exercise ran.

What you can safely check

Write down or photograph any code on the display and confirm the controller is set to automatic. Beyond that, leave the unit, the transfer switch and your panel closed. They hold fuel, battery power and live electrical parts.

A gas smell near the generator or in the house means go outside at once and call 911 or the gas company from a safe distance. Do not try to restart anything.

Common causes

Many repair calls turn out to be routine. Others need parts and a return trip. A technician usually diagnoses first and quotes before doing major work.

• A starting battery at the end of its life
• A failed battery charger or blown control fuse
• Fouled spark plugs or a clogged air filter
• Low oil level or low oil pressure shutdowns
• Controller errors needing a reset or update
• Transfer switch faults
• Wiring damage from mice or other animals

Repair or replace

Weigh the generator's age, its service history and how easy parts are to find. A modest repair on a well-kept unit is usually money well spent. A big engine job on an old unit that missed years of service may be throwing good money after bad. Get the repair price and a replacement price in writing, and ask whether replacing would also trigger a new transfer switch, a gas meter upgrade or a fresh permit. Angi notes that major engine work can cost far more than a typical service call.

Details that help the technician

Have the brand, model and serial number ready, usually printed on a label on or inside the enclosure. Note the fault code, when the problem began and when the unit was last serviced. Mention whether the problem shows up during the weekly exercise, during outages or both. With that information, the technician can often bring the right parts on the first trip.

Avoiding the next repair

Most repair calls could be caught at a routine service visit. A yearly tune-up, a battery swapped before it fails and an enclosure kept clear of leaves and nests go a long way. When a storm is in the forecast, glance at the status light and confirm the unit is ready and in automatic mode.

If a warning shows up, book service before the weather turns.

Questions homeowners ask