The question of “how long will my whole home generator last” has a wide range of answers ranging from, “It will fail to start if it is not properly maintained” to “In theory it could run indefinitely if superhuman efforts were made while it is running”. Both of these extreme answers are technically true.
But let’s assume you have a decent whole home generator, you keep it maintained to manufacturer’s specifications and there are no unusual circumstances that would interfere with normal operation. Your answer would still depend on two key factors; your fuel source capacity and how much of the house you have powered up will affect the load you are drawing from your whole home generator.
If you’re looking for the best whole home generator options, we highly recommend looking at our guide Diving Into the Best 5 Whole Home Generator Options In 2020
First, below is a table with our recommendations for four incredible whole home generators.
Fuel For Whole Home Generator Longevity
Fuel is the easiest variable to answer. When the fuel tank runs to empty, your whole home generator will stop running. Gasoline or diesel fuel tanks can be installed in larger capacities to increase runtime but there is still the limiting factor of size and the fact that these sources can go stale over time. If you have a fully topped off 150 gallon tank but you haven’t used it in three years, chances are that fuel will cause problems in your whole home generator’s engine.
Liquid Propane (LP) won’t go stale and can be stored indefinitely in a large tank. Many whole home generators are set up by default to handle LP gas as this is a common choice for many homeowners who do not have access to natural gas. Natural gas is a great choice for whole home generators because it is commonly fed from the city with a never-ending supply and is contained in underground pipes that won’t be damaged in a storm.
Determining Needs By Generator Load
A more difficult variable to gauge is the load you are placing on your whole home generator. A large capacity generator can run forever if the only load is a single LED bulb and it will run considerably shorter than expected if you run every large motor and heavy current device you have the entire time.
You should familiarize yourself with how much current each device draws and be wary of running heavy draw devices continuously. Large motors such as air conditioners are critical during a power outage, but consider turning the thermostat a few degrees off-optimal to lessen your current draw. Clothes dryers, oven range, and vacuum cleaners are also high draw devices.
Your water heater is another major energy draw that will sap your whole home generator of run time so you should be aware of the current draw of each device or possibly have an amp meter installed at your generator’s transfer switch to keep you advised of how much you are drawing and how it is cutting down on your runtime.
Final Thoughts on Whole Home Generator Run Times
All things being equal, you can manage your current draw to the best of your ability and you can keep your fuel tank topped off and ready to run forever, there is one limiting factor that will shut down your whole home generator and that is your oil. Engines are not made to run at high speed forever and will need to be shut down occasionally to change out the oil.
Most manufacturers recommend an oil change every 50 hours of runtime as the oil will lose its viscosity, stop lubricating and cooling the engine parts. If you keep your fuel and current draw in check, you should shut down your whole home generator every two days to complete an oil change and then you can start it right back up and keep on generating power!
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