Standby Generator Maintenance

Standby Generator Maintenance

Published: February 1st, 2017

Standby Generator Maintenance…Some questions answered…What you should know.

Due to the recent increase and length of power outages across the region, residential standby generator systems are becoming a necessity to protect your home and family.   Properly installed residential generator systems can cost  from $5500.00 to  $50,000.00 or more. In order to get the most from this investment I advise that you make sure your unit receives regular professional maintenance and, if needed, repairs.  Generator maintenance is much more complicated than merely changing oil and air filters. I cannot stress enough, the importance of regular professional generator maintenance.  The following are a few questions I am frequently asked regarding generator care.

Question:  How often does my standby generator need to have maintenance  performed?

Answer:  Maintenance should be done after 50 hours of run time or once a year whichever comes first. If a generator is older than 5 years, it is a good idea to have semi-annual maintenance performed.  The oil level and clarity should be checked after any power outage of more than a couple of hours.

Question:  What services should be done to the unit at a minimum?


  1. The oil should be changed (most units utilize synthetic motor oil). The owners manual should be consulted for the type, viscosity and volume.
  2. The oil filter, air filter and spark plugs should be changed.  Any pre-air filter should be cleaned. Oil leaks must be dealt with immediately. If the oil level drops, the unit will shut down and will not restart until the oil pressure is normal.
  3. The health of the battery and charging system should be checked.  Battery failure is the number one reason that generators don’t start.  If the charging system is not functioning properly, your battery will fail in short-order.
  4. The air intakes and systems of air hoses (or coolant hoses) must be inspected.  Any debris blocking air intakes and exhaust must be cleared.  Any air leak on a standby air-cooled unit is going to cause an eventual failure.  Units will shut down for high temperature, or poor electrical output due to an over-heated condition.  Low coolant level will also cause a shut-down.  Generators experiencing a fault like these will not restart until the cause of the fault  is dealt with.
  5. The engine must be adjusted for RPM and the throttle/linkage should be adjusted.  If needed, valve adjustment should be undertaken at this time. The engine must operate at the same output level it produced when new.
  6. The electrical output of the generator must be adjusted at least once per year. 
  7. In some cases, the service must be logged in to the on-board controller.

Question:  Who should service the unit?  

Answer:  Only an authorized servicing dealer should attempt to service these units.

Electricians, even those who claim to have the knowledge to install and service these generators rarely possess the training, knowledge or equipment required to adjust todays sophisticated gensets.  The units are now controlled by on-board computers andonly highly-trained individuals, possessing the diagnostic equipment specific to that make (brand) of product should attempt to adjust them.  The adjustments are subtle, but are numerous and closely-linked to other functions that are critical to it’s performance.  In short, only a professional certified generator service technician should be performing maintenance or service on these units.          

Question:  Where can I find a factory-authorized, service technician for my generator?

Answer:  There is only one place….on the manufacturers website.  Most manufacturers have a tab to find  a dealer or servicing agent.

Anthony’s advice….The old cliché “you get what you pay for” is strongly evidenced by the experiences of those who don’t heed its warning.  Do not attempt to service a standby generator yourself.  A small error, or over-adjustment can cause a serious problem.  What you wind up paying for professional service can vary, but the quality of the service is usually comparable.  In general, If you use a factory-authorized service technician, you are protecting a sizeable investment that was made for the well-being of your family and possessions.  This is not the right place to skimp.  If you must, widen the time-gap between professional service…do not substitute for it.

Generators PA is written by Anthony Guerrera of Guerrera & Sons Electric, Inc.