10 October 2026
How often should a diesel generator be serviced?
Typical service intervals for standby and prime diesel generators, plus the simple checks that keep a backup set ready to start.
The short answer
Most diesel generators need a full service at least once a year, or sooner based on running hours — often every 250 to 500 hours. Always follow the engine maker's schedule for your model.
Standby generators
Backup sets can go months without running, so the biggest risk is that they won't start when the mains fails. Run them regularly (many operators do a short monthly test, ideally under load) and service them yearly even if hours are low.
Prime power generators
Sets running every day rack up hours quickly, so they're serviced on hours rather than the calendar. Oil, fuel and air filters are the usual items.
Simple checks between services
Check oil and coolant levels, look for leaks, keep the battery charged, drain water from the fuel filter and keep the fuel fresh. Diesel left for long periods can grow bacteria and block filters.
We can help
We offer servicing and genuine parts for the generators we sell. Get in touch for a service plan.