Standby Generator Maintenance Checklist
Ensure your generator starts when you need it — weekly run tests, ATS verification, load bank testing, fuel system checks, and battery maintenance for building resilience.
What is a generator maintenance checklist?
A standby generator maintenance checklist is a structured list of the 12 preventive maintenance tasks — covering visual, functional, safety and record-keeping checks — that keep a standby generator running safely and reliably. It groups routine checks by frequency, from daily inspections to annual servicing, so FM teams and building engineers can plan and evidence preventive maintenance.
Core generator checks
- Check engine oil level, coolant level, and fuel level
- Start the generator on manual test and run for the recommended period
- Test emergency stop and remote shutdown functions
- Record run hours, voltage, frequency, oil pressure, and coolant temperature
What is a standby generator?
A standby generator provides emergency electrical power when the mains supply fails. Diesel generators are the most common type in commercial buildings, automatically starting within seconds of a power outage via an automatic transfer switch (ATS). Generators protect critical loads including life safety systems, lifts, IT infrastructure, and essential building services. Regular testing and maintenance are essential to ensure the generator starts reliably when needed.
Typical Generator maintenance checklist
A practical starting point for planned preventive maintenance. Always refer to the manufacturer's O&M manual and site-specific requirements.
Visual Checks
- Check engine oil level, coolant level, and fuel level
- Inspect the exhaust system for leaks, corrosion, or lagging damage
- Check the fuel system for leaks and inspect fuel filters
- Inspect air intake filter and cooling system fan
- Check fuel storage tank level and condition
Functional Checks
- Start the generator on manual test and run for the recommended period
- Verify the automatic transfer switch (ATS) operates correctly on simulated mains failure
- Check battery voltage, electrolyte level, and charger operation
- Verify the block heater is maintaining engine temperature
- Check alternator output voltage and frequency under load
Safety Checks
- Test emergency stop and remote shutdown functions
Record Keeping
- Record run hours, voltage, frequency, oil pressure, and coolant temperature
Typical maintenance frequency
Suggested intervals for standby generator maintenance. Actual frequencies should follow manufacturer guidance and site-specific risk assessments.
Weekly
- •Visual inspection and no-load run test
- •Check oil, coolant, and fuel levels
- •Battery voltage check
Monthly
- •Run under load (building load or load bank)
- •ATS transfer test
- •Check air filter and belts
Annually
- •Full engine service (oil, filters, coolant)
- •Load bank test to rated capacity
- •Battery replacement if required
- •Fuel quality test and tank inspection
- •Electrical system checks
Common faults and issues
Issues to be aware of when maintaining standby generator equipment.
Safety and compliance notes
Key safety considerations for standby generator maintenance. This is general guidance only — always follow OEM instructions, statutory requirements, and your organisation's safe systems of work.
Managing Generator documentation with PM Assist
PM Assist helps FM and building operations teams search their O&M manuals and building drawings in seconds. Upload your standby generator documentation and ask questions like “What is the generator fuel capacity and run time?” or “When was the last load bank test?” — and get source-cited answers instantly.
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