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.
Also available as editable Excel and Word — with asset, sign-off and findings columns.
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.
This checklist is one of 17 in our electrical maintenance checklists, covering distribution boards, switchgear, generators, UPS, solar PV and EV charging — inspection, testing and thermographic checks.
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
Download the free Generator maintenance checklist PDF
Get all 12 tasks as a printable PDF — free, no signup needed. Keep a copy in the plant room, attach it to work orders, or share it with your maintenance contractor.
The PDF is free and needs nothing. The Excel and Word versions add asset details, sign-off and findings columns so you can record the work as you do it — we ask for an email address for those.
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.
Reference standards and frameworks
- United Kingdom
- BS 7671 (IET Wiring Regulations) and the Electricity at Work Regulations 1989
- North America
- NFPA 70B (electrical equipment maintenance) and ANSI/NETA MTS
Frameworks commonly referenced when planning generator maintenance programmes. Always confirm the requirements that apply to your site and jurisdiction.
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.
The checklist tells you what to check. The manual tells you the numbers.
Ask a generator manual a question and get the answer back with the page it came from. No signup, and you can drop in your own PDF instead of the sample.
“What is the generator fuel capacity and run time?”Runs against a sample chiller manual so you can see the shape of the answer — then try it on one of yours.
Take this checklist with you
Download the branded PDF, generate a custom version for your asset, or run AI search across all your building documentation.
Related free tools
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Further reading on generator maintenance
Compliance topics for generator maintenance
Compliance & CAFM
Run standby generator maintenance in PM Assist
This checklist is also a planned maintenance programme in PM Assist, included in every paid plan alongside the compliance register and mobile inspections.
- Add a standby generator to a building's asset register and this maintenance programme is created for you, with each task on its frequency in the planner.
- Standby Generator Service & Load Test is tracked on the compliance register, with the date last done, the date next due and the certificate.
- Contractors can be given a login to see their jobs and upload certificates.
Frequently asked questions
How often should a standby generator be tested?
What is wet stacking?
How long should generator fuel be stored?
Manage your building documentation with AI
PM Assist gives FM teams instant access to O&M manuals, drawings, and maintenance knowledge — all searchable with AI.
- Upload and organise building documentation
- AI-powered search across all your manuals
- Source-cited answers for maintenance queries
- Team collaboration and access control
- No credit card required to start