generators and ups

Fuel Polishing

Fuel polishing is important for keeping your power systems running to their optimal condition and protecting your power supply.

Fuel Polishing

Why does fuel need polishing?

As an organic compound, diesel fuel is liable to deteriorate over the natural course of time. In doing so, it gradually leaves sediment in a diesel generator’s tank. Fuel polishing restores your diesel to optimum condition, removing all fuel contaminants. Without regular fuel cleaning, your generator’s power will be reduced, the filters and pistons will become clogged and you may even suffer a complete generator failure and need to have expensive repairs to your backup power system.

Water, usually appearing as condensation, is the most likely fuel contaminant. In itself, it can affect the power output of a diesel generator, but it also encourages micro bacterial growth in the fuel tank. The microbes feed on the diesel and their waste leaves additional sludge in the bottom of the tank and particles floating throughout.

It takes only a few months for fuel sitting idle to begin to deteriorate

With regular fuel polishing, all traces of contamination – all the sludge, all the water, all bacterial growth and any solids or debris in the fuel tank – are removed. Once we’ve carried out the fuel polishing, we treat the remaining diesel with a chemical biocide to slow future bacterial growth.

If fuel is left too long without being filtered and cleaned, it can need replacing entirely. As providers of long-term generator hire, we also offer a rapid generator refuelling service – but if you keep your fuel polished you won’t need to spend extra money on more diesel.


  • Prevents build-up of sludge in the generator, fuel filters and pistons and removes all traces of contamination present in the fuel, re-optimising it
  • Prevents water entering the generator
  • Ensures a more reliable standby power system
  • Secondary process (no effect on the operation of the Generator)
  • Simple, safe and cost-effective

For more information regarding our products and services, please contact the Shenton Group customer support team

generator maintenance

Services offered

For more information on our maintenance and monitoring services please see our maintence and monitoring page.

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