Generators are vital for homes and businesses and can provide a lifeline for when worst-case scenarios occur. Power outages, whether they are due to bad weather or electrical grid issues, can cause financial problems and disrupt lives. Having a generator available to use, either a standby generator or a portable one, can act as a lifeline and provide power to your home or business when you need it most. 

However, although generators are mostly self-sufficient, there some tips that will help you to keep your generator in the best possible condition, ensuring that it will always perform when you need it. Some of these tips may be more suitable to individual styles of generator, such as standby or portable, but we guarantee you’ll be able to implement some of these into your maintenance routine.

Regular Preventative Maintenance & Servicing Tips For Generators


Much like in a car engine, oil within a generator plays a vital role and should be regularly checked and topped up where necessary. Before checking, allow the oil to drain back into the crankcase, ensuring you adhere to the manufacturer’s guidance regarding oil viscosity and classification. We’d always suggest using the same brand and quality of oil when topping up the generator.

You should also regularly change the oil and filter to keep the generator running smoothly. Again, adhere to manufacturer guidelines concerning the draining of fuel and filter replacement to ensure that everything continues to function as it should.

Cooling System

Even during periods of inactivity, it is advised to regularly check the coolant to ensure it is at the required level. You’ll also want to clean the radiator to ensure it is free of debris, muck and foreign material and can operate without obstruction.

Fuel System

If your generator has not been called into action recently, you should consider implementing a schedule of regular exercise to allow the engine to run and use up any old fuel. If you have a diesel-powered generator, this fuel will only have a viable lifespan of a year before it begins to slowly corrode and become contaminated. Therefore, switching the generator on will not only allow you to see if the engine is running smoothly but also to use old fuel reserves before adding fresh.

If your generator has been sat with a large reserve of fuel for between six to twelve months, you may want to consider polishing the fuel to ensure that it can be used without causing damage to the engine.

Battery Quality

Although you may not think it, your generator battery is one of the most important components of the device. They are also a common cause of startup failure, especially if they are undercharged or have not been kept in the best condition. To keep your battery up to specification, regular and thorough testing is required to help you avoid any startup hitches.

For larger, more industrial-sized generators, you’ll want to conduct a thorough test of your battery, rather than simply checking the output voltage, as this may not provide adequate results. The best way to test a battery is by using a load. Depending on the model of generator, this may be done automatically each time the generator starts, or this may have to be carried out manually using an artificial load to check the battery’s condition and quality.

You’ll also want to keep your battery visibly clean, which can be done by wiping away any dirt or grime with a damp cloth. You should also inspect the terminals, to see if there is any rust corrosion present. If yes, then remove the battery safely and clean the terminals using a solution of baking soda and water (six heaped tablespoons to roughly 950ml of water). You should then rinse with clean water and apply a light layer of petroleum jelly to the terminals.

Regular Schedule of Engine Exercise

Much like humans, engines require regular (or at least semi-regular) exercise to ensure they don’t seize up. Regular exercise gives the benefit of minimising the risk of oxidation and uses older fuel at the bottom of the tank. Additionally, regular exercise ensures reliable engine starting for when the generator is required to kick in and serve its purpose.

You should conduct engine exercise at least once a month for 30 minutes or more. This should always be done at a load of no less than one-third of the manufacturer’s maximum load rating. Additionally, you could look at implementing a load bank testing schedule to burn off wet stacking and test your generator to a full 100% load.


Finally, regularly check the exhaust section of the generator to ensure no blockages or debris are obstructing the airflow. If there are any weak points in the exhaust system, they should be repaired immediately to avoid the possibility of further damage.

For more information on taking care of your generator, check out our blog!