Generator service – What is it and is it worth doing?

“It’s just a generator…” — we hear that a lot. And then failures, downtime and questions appear: why, after changing the oil and filters, does the generator still not work?

The most common questions about generator servicing

Clients (ours and not ours) usually ask:

  1. What tasks are performed during generator servicing?
  2. How much does generator service cost?
  3. Does servicing extend the generator warranty?
  4. How many operating hours / how often should a generator be serviced?
  5. My mechanic replaced the filters and oil, and the generator still doesn’t work — what should I do?

In a few simple points, we’ll answer these questions and show that generator service is much more than changing oil and filters.

Who should service a generator set?

Generator servicing should be carried out by an experienced electro-mechanic with the right knowledge, training, experience and authorizations to perform service and repair work.

A generator set converts mechanical energy into electrical energy. That’s why, in addition to mechanical skills, proper electrical qualifications are required (in Poland: SEP E1 – operation of generator sets).

Improper service can endanger both the person performing the work and anyone who uses the unit afterwards.

1) What tasks do we perform during generator servicing?

The scope depends on how the generator is used:

  1. Manual operation – the generator powers loads directly (machines, devices).
  2. Automatic mode – operation with an ATS transfer switch.
  3. Synchronization – Generator – Generator.
  4. Synchronization – Generator – Mains.

In this article, we focus on example no. 1 (manual operation) — the simplest setup where the generator powers loads connected directly to it.

Stage 1: Initial assessment and preparation

We start with a visual inspection of the entire generator set. An experienced technician will quickly spot irregularities and early signs of problems.

Next:

  • we take a coolant sample and use a refractometer to determine the freezing point,
  • we test the starting batteries with a proper tester (measurements confirmed by a printout).

Then we proceed according to the checklist:

  1. Visual assessment of the unit and checking total operating hours
  2. Measurement of coolant freezing point
  3. Inspection and testing of the generator starting batteries
  4. Inspection of the battery charger and auxiliary supply (if connected)
  5. Inspection of the engine block heater system (if connected)
  6. Checking engine oil level before start-up
  7. With approval from the person supervising the generator, we start the unit, warm up the engine and move on with further steps

Stage 2: Parameter checks during warm-up

During warm-up we check key mechanical and electrical parameters:

  • single-phase and three-phase voltage,
  • frequency,
  • engine speed (RPM),
  • oil pressure,
  • engine temperature,
  • charging system and alternator,
  • control system and controller plus monitoring and measuring indicators.

Stage 3: Proper service and consumables replacement

  1. After warm-up we shut down the engine and secure the unit against accidental start-up
  2. Engine oil change and disposal in accordance with regulations (in Poland: BDO)
  3. Replacement of oil filter(s) and disposal in accordance with BDO
  4. Replacement of fuel filter(s) and disposal in accordance with BDO
  5. Replacement or cleaning of air filter(s); if replaced — disposal in accordance with BDO
  6. If necessary — coolant replacement and disposal in accordance with BDO
  7. Inspection of engine and alternator vibration isolators
  8. Checking condition and connections of rubber hoses in the cooling system and engine block heating circuit
  9. Inspection of the engine cooling system and radiator(s) (if more than one)
  10. Inspection of ventilation
  11. Inspection and checking alternator belt tension
  12. Inspection of the exhaust discharge system
  13. Inspection of bolted and mechanical engine connections
  14. Inspection of alternator housing and verification of alternator fan condition
  15. Checking electrical connections
  16. Inspection of the starting system
  17. If necessary — alternator insulation resistance measurement

Stage 4: Cleaning, self-check and post-service test

After the work is done, we clean the enclosure, engine, alternator and other components, while verifying that no mistake occurred during replacements or any repair.

Then we start the generator again and re-check all warm-up parameters — comparing readings from before and after service.

Post-service test run: operation under load is recommended.

Finally, we prepare a service report describing the work performed, technical condition, observations and recommendations for further operation.

That’s what properly performed generator service looks like — in practice and with responsibility.

2) How much does generator service cost?

The price depends on the generator power rating: the higher the power, the higher the cost. You can find our current price list here:


We use only factory-grade components: branded, original parts intended for the specific machine. We do not use cheaper substitutes or counterfeits.

Why does it matter? Because “it fits” does not mean “it works”. This includes, for example, oil filters with internal valves (there are several types), as well as fuel filters. Incorrect fuel system operation is the source of many problems, and lubrication errors can result in very expensive repairs or complete engine failure.

So why does service cost what it costs?

  • Because we use original parts, filters, fluids and oils.
  • Because proper service requires expensive but essential diagnostic, mechanical and electrical tools.
  • Because disposal of materials costs money and is done correctly — in accordance with regulations (in Poland: BDO).
  • Because the work of a skilled, experienced electro-mechanic also has a cost.
  • Because a well-performed service takes time.
  • Because you remember quality longer than a low price.

For some, our prices are unacceptable; others say it’s too cheap. We have chosen knowledge, experience and quality for 25 years — and we take responsibility for the results.




3) Does servicing extend the generator warranty?

The answer is simple:

If you have the manufacturer’s authorization — YES. If not — NO.

In Poland there are several major generator manufacturers and dozens of importers. Most have their own service solutions. That’s why, when purchasing a generator, it’s important to choose a brand with professional service support.

If you want efficient and reliable service, choosing HIMOINSA generator sets is a very good decision. You can use our AUTHORIZED service — APEX GENERATORS — or the manufacturer’s service at HIMOINSA Poland.

We are authorized to carry out periodic service inspections for HIMOINSA generator sets — and such service extends the warranty by another year or to the date declared in the manufacturer’s warranty.

4) How many operating hours / how often should a generator be serviced?

This depends on the engine manufacturer installed in the generator set. In our standard offer you will find, among others:

  • FTP IVECO — every 500 operating hours or once per year
  • SCANIA — every 500 operating hours or once per year
  • MITSUBISHI — every 300 or 500 operating hours (depending on model) or once per year
  • YANMAR — every 300 or 500 operating hours (depending on model) or once per year
  • HYUNDAI/DOOSAN — every 300 operating hours or once per year

There are also special (more advanced) versions that allow extending service intervals to several thousand operating hours.

5) Oil and filters were changed, but the generator still doesn’t work — what now?

Very simple: call an experienced service team.

After unsuccessful repairs or interventions by people who do not specialize in generator sets, Clients often look for “phone support”. Meanwhile — as stated above — changing oil and filters alone is not service.

The best solution is to find a service provider specializing in generator service and repairs and order a proper inspection. Remember: a good service team is “a treasure”, and that’s why some providers are reluctant to take over a unit “after someone else” — there are few specialists.

Sometimes you have to wait for an available slot. Don’t get discouraged — good service is worth waiting for.

We encourage you to contact us. We will honestly tell you whether we will take on your generator, at what cost and within what timeframe. You will get a clear answer: we repair it or we don’t.

Best regards,
APEX GENERATORS
tel. 515 087 068


Article / guide written by a human, not by artificial intelligence (AI)