At a glance: generator servicing
- Service intervals vary by model and usage, so always follow the maintenance schedule in your generator’s manual.
- Petrol and dual-fuel generators commonly need oil, air-filter and spark-plug maintenance.
- Diesel servicing can also include oil filters and fuel filters, depending on the model.
- Checks between services can catch low oil, leaks, dirty filters or changes in performance before they become bigger problems.
- Always use the oil, filters and replacement parts specified for your generator.
Generator servicing is easy to forget when your generator spends more time stored than running.
But whether you use yours for home backup, camping, tools or regular work, servicing keeps it ready for the next time you need power.
A service is more than an oil change. Depending on the generator, it can involve filters, spark plugs, fluid levels, fuel-system checks and a general inspection for wear, leaks or damage.
How often this needs doing depends on the model and how much you use it. Your generator’s maintenance schedule should always be your starting point.
Why does a generator need regular servicing?
A generator combines an engine with electrical components, so both need to be kept in good working order.
Servicing can help you:
- Identify wear before it becomes a bigger problem
- Keep engine oil at the correct level and condition
- Keep air and fuel systems clean
- Maintain reliable starting
- Reduce the risk of problems when the generator is needed
- Keep up with manufacturer maintenance requirements
That still matters if the generator only runs occasionally.
A backup generator can sit unused for long periods, but that doesn’t mean it can be forgotten until the next power cut.
What does a generator service include?
Exactly what’s involved depends on the generator, engine and fuel type, but several areas come up regularly.
Engine oil
Engine oil protects the moving parts inside the engine, so checking its level and condition is a basic part of generator maintenance.
Oil changes should follow the interval and oil specification in your generator’s manual. Don’t assume the same oil or schedule applies to every model.
Some generators include a low-oil shut-off sensor to protect the engine if the level drops too far, but that doesn’t replace regular checks and oil changes.
Air filter
The air filter helps stop dirt and debris entering the engine.
A dirty filter can restrict airflow, so inspect it regularly and clean or replace it as specified for your generator.
If you use the generator in dusty or dirty conditions, it may need checking more often.
Spark plug
Petrol and petrol/LPG dual-fuel generators use spark plugs as part of the ignition system.
Depending on the maintenance schedule, the spark plug may need inspecting, cleaning, adjusting or replacing.
It’s a routine service item on many petrol and dual-fuel generators alongside engine oil and the air filter.
Fuel system
Fuel-system maintenance depends partly on the fuel you use.
With a petrol generator, storage matters because petrol left for extended periods can deteriorate. Follow the manufacturer's guidance on fuel storage, especially if the generator will be unused for a while.
A dual-fuel generator gives you the option of petrol or LPG. LPG doesn’t deteriorate in storage in the same way as petrol, which can make fuel management simpler if you only use the generator occasionally.
How often should you service a generator?
There isn’t one service interval that applies to every generator.
The correct schedule is the one specified for your model. Manufacturers may base maintenance on running hours, elapsed time or both.
How you use the generator matters too. A machine used regularly for tools or work can build up operating hours far faster than one kept mainly for occasional backup.
It's worth keeping a record of your running hours and maintenance so you know when the next service item is due. If your generator has an hour meter or digital display, that can make tracking usage easier.
Does a generator need servicing if you rarely use it?
Yes. Low running hours don't mean a generator can be stored indefinitely without attention.
Oil, fuel and other components can still be affected by time and storage conditions. Before relying on a generator that hasn't been used for a while, check it in line with the manufacturer's instructions.
That matters particularly for backup power. Discovering a starting problem during a power cut is far worse than finding it during a routine check.
How do you maintain a petrol generator?
For many portable and general-purpose petrol generators, routine maintenance centres on the engine and fuel system.
Depending on the model, that can include:
- Checking and changing engine oil
- Inspecting or replacing the air filter
- Inspecting and replacing the spark plug when required
- Checking the fuel system
- Inspecting the generator for leaks or damage
- Keeping cooling and ventilation areas clear
- Checking fasteners and connections where specified
Typical petrol-generator service items include engine oil, an air cleaner and a spark plug.
Always use the maintenance schedule and specifications for your individual model rather than treating a general checklist as a replacement for the manual.
Is dual-fuel generator maintenance different?
Much of the engine maintenance is similar because a dual-fuel generator still uses an internal-combustion engine with oil, an air filter and spark plug.
The difference is that you also have the LPG side of the fuel system to consider. Hoses, regulators and connections should be used and checked according to the manufacturer's instructions.
One practical benefit of LPG is storage. Unlike petrol, it doesn't deteriorate in the same way over time, which can make fuel management easier if your generator is only used occasionally.
That doesn't make a dual-fuel generator maintenance-free. Oil, filters, ignition components and the rest of the generator still need routine attention.
What about diesel generator servicing?
A diesel generator has different service requirements because it uses a compression-ignition diesel engine rather than spark plugs.
Depending on the model, servicing can include:
- Engine oil
- Oil filter
- Air filter or cleaner
- Diesel fuel filter
- Fuel-system checks
- General inspection and maintenance
A typical diesel service can include engine oil, an oil filter, a diesel fuel filter and an air-cleaner element.
Diesel servicing is especially important where a generator is being used regularly or for sustained workloads, as operating hours can build quickly.
What can you check between generator services?
You don't need to wait until a full service to pay attention to your generator.
Before and between uses, it's sensible to keep an eye on:
- Engine oil level
- Fuel level and condition
- Air filter condition
- Visible fuel or oil leaks
- Loose or damaged components
- Unusual noises or vibration
- Warning indicators
- Cables, sockets and controls
- General cleanliness and ventilation
Only carry out checks and maintenance that are covered by the manufacturer's instructions and that you're confident carrying out safely. Switch the generator off and allow it to cool before carrying out maintenance as directed in the manual.
Can you service a generator yourself?
Some routine maintenance can be straightforward if you're comfortable doing it and follow the manufacturer's instructions.
Tasks such as checking oil levels or replacing specified service items may be covered in your owner’s manual. Using the correct service parts for your model also reduces the risk of fitting something unsuitable.
More involved faults, electrical problems or anything you’re not confident diagnosing should be handled by someone with the right knowledge and experience.
If your generator is still under warranty, check the servicing requirements before carrying out work yourself.
Signs your generator may need attention
Don't wait for the next scheduled service if the generator isn't behaving normally.
Here are a few signs you should investigate:
- Difficulty starting
- Rough or uneven running
- Unexpected shutdowns
- Unusual smoke
- Excessive vibration
- New or unusual noises
- Visible fuel or oil leaks
- Warning lights or fault indicators
- Noticeably different performance
These symptoms can have several causes, so avoid assuming that replacing one service item will necessarily solve the problem.
Keep your generator ready for the next job
Good generator maintenance comes down to consistency.
Follow the service schedule, keep an eye on the basics between services and deal with faults instead of leaving them until the generator is needed.
If you’re unsure which service parts you need or what maintenance your generator requires, get in touch with us. We can help you work out the right next step.
