Top 5 Maintenance Mistakes That Shorten Generator Lifespan

Proper generator maintenance is the key to preserving a unit through its full intended lifespan and often longer. When maintenance is ignored or performed incorrectly, a commercial generator faces avoidable wear and may suffer failures that shorten its service life. Routine attention to basic maintenance tasks protects the engine, electrical components, and cooling system. These issues are preventable with preparation and a clear understanding of how backup generators operate.

Ignoring Oil and Air Filter Changes

A generator operates through the rotation created by a combustion engine, which relies on clean, well-circulated oil. Similar to automotive engines, a backup generator needs regular oil changes to maintain proper lubrication. When oil ages, it thickens and collects contaminants that settle in the engine. This can restrict movement within the engine block and reduce efficiency over time.

Air filters have a direct effect on both performance and temperature. A clogged air filter limits airflow, causes the generator engine to run hotter, and reduces its ability to release exhaust. Restricted airflow also increases the concentration of harmful particles inside the engine compartment. Regular oil and filter changes are basic generator service tasks that directly support generator lifespan.

Failing to Replace Fuel After Its Shelf Life or Using the Wrong Fuel

Fuel degradation is a lesser-known issue that affects both diesel and natural-gas units. Diesel fuel begins to break down after about three years in storage, and natural gas typically holds for about one year. As fuel ages, it becomes more likely to contain moisture and organic growth. This can obstruct fuel lines, damage injectors, and interfere with the engine’s ability to maintain stable combustion.

Using the wrong fuel type can also harm internal components. For example, diesel with a high water content can cause corrosion, and natural-gas supply issues can lead to weak ignition. Fuel testing and replacement at regular intervals are essential parts of any commercial generator maintenance plan.

Using a Generator Too Small for Its Application

Choosing a generator that cannot support a facility’s full load is one of the most common mistakes operators make. Proper sizing requires calculating the running watts of every system the generator must support at the same time and then adding a 20 percent margin. This margin accounts for startup surges, minor load spikes, and any additional equipment used during emergencies.

A generator that is consistently pushed beyond its rated capacity will overheat, which creates long-term engine stress. Overloading may also trip breakers, damage sensitive equipment, or cause the generator to shut down unexpectedly. Correct sizing ensures steady operation and reduces unnecessary strain on the engine.

Running Down the Battery

The battery supplies power for the starter motor and for safety features such as remote monitoring and alerts. When a battery becomes weak or corroded, it may prevent the generator from starting at all. Because many facilities only discover battery issues during an outage, routine testing is essential. Voltage checks, terminal cleaning, and scheduled battery replacement all support long-term generator performance.

Neglecting Cooling and Ventilation

Overheating remains one of the leading causes of failure in standby generators. Low coolant levels, faulty cooling fans, and blocked airflow can quickly force an engine into unsafe temperature ranges. Heat also accelerates wear on internal parts and can cause immediate shutdowns. Cooling components should be inspected regularly and replaced as soon as they show signs of wear.

Prevent Costly Mistakes with a Maintenance Contract

These issues might seem small, but they’re exactly what lead to shutdowns, expensive repairs, and early replacement. GenTech offers maintenance contracts that provide scheduled inspections, oil service, battery testing, fuel checks, and full system evaluations. Our technicians help ensure your generator is ready when needed.

Contact us today to learn more and protect your generator for the long term.