Relying on a backup generator to kick in when there is an outage gives that extra level of security needed, especially to organisations that face high stakes should they lose power, such as hospitals and emergency services.

During 2016, ‘…a major hospital in Adelaide’s southern suburbs, was affected when the fuel pump for the diesel-powered back-up generator failed after operating for about an hour,’ [Source] and some of the larger companies were affected financially to the cost of $13 million during that infamous blackout. [Source]

But an essential part of the investment is to ensure that the correct checking and maintenance has occurred on the equipment, otherwise you run the risk of potential failures, damage or poor functioning as well as efficient combustion and to prevent wet stacking.


Despite installing a premium piece of machinery, regular maintenance is key to its functionality and when it needs to work, it’s not a time to fail. To ensure best performance and a longer lasting generator (which will save you money and hassle long term), it’s essential that proper periodic maintenance is executed.

The benefits of preventative maintenance are far reaching but importantly, you can work it into your human resources schedule and budget, rather than waiting for disaster to strike outside of normal working hours. Plus, it provides increased reliability and improved efficiency.

Read more about the benefits of maintenance here.

Whilst leaks, smoke, unwanted sounds are primary indicators that repair is in order, don’t neglect the other, seemingly minor checks to prevent the worst outcome. The unit requires regular visual inspections, and the electrical, fuel and cooling systems need to be checked.

Here are some general guidelines of what tasks we include in our regular maintenance. They should be performed by a qualified diesel mechanic or technician.

(Link to download checklist at end of this article).

Monthly generator maintenance checklist:

  • oil levels are correct
  • radiator core for fouling
  • radiator hose condition
  • block heater working
  • fuel level litres added
  • fuel solenoid linkage for security
  • governor operation
  • voltage regular adjustment
  • start battery electrolyte level
  • control battery electrolyte level
  • charging voltage
  • housekeeping clean up
  • record hours run time on start
  • record kwh meter reading
  • check fuel oil water and exhaust for leakage.

Quarterly generator maintenance checklist:

In addition to everything above, you should also check on the following items:

  • fan belt tension
  • fan belt wear
  • check battery terminals
  • conduct a thorough clean on the battery terminals.

Battery failure can be amongst the most common problems, so paying attention to the condition of it will be most beneficial.

Annual generator maintenance checklist:

  • change engine sump oil
  • change full flow oil filter
  • empty, flush and refill radiator
  • change bypass oil filter
  • flush daily service fuel tank
  • change fuel filter
  • change air filter
  • check and clear crankcase breathers
  • check all nuts, bolts and clamps
  • check starter motor solenoid
  • check all electrical connections
  • clean engine
  • remove and clean air grilles
  • inspect/check all alternator output connections
  • clean alternator
  • inspect all components and cubicle
  • inspect all wiring and terminals
  • clean switchboard
  • test with load.

At least once a year, it’s crucial to test your backup generator at full load to ensure it is working, for at least an hour at 100 per cent capacity. It’s a vital step that shouldn’t be overlooked and is needed to see if the generator can take the absolute full load that it could be required to do, and spot any maintenance issues well ahead of time. It also has the additional benefit of dislodging any damaging build up.

It’s important to form the mindset of ‘not if but when’ an outage will happen and you need to use your generator. This helpful guide is a useful practice to incorporate as part of your due diligence and maintenance systems.

Finally, here are some additional questions you may like to consider:

  1. Is there enough fuel and proper fuel storage for extended blackouts, and is it stored approriately?
  2. Is it time to upgrade your generator and/or related equipment?
  3. Are all damages logged and attended to immediately?
  4. Have you investigated fuel polishing to ensure optimised equipment?


Download our Ultimate Generator Maintenance Checklist here.


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