Generator Maintenance Tips
Manufacturers and repair pros share tips to avoid the most common mistakes.
Don’t Get Burned by Wattage Ratings
Every generator lists two capacity ratings. The first is “rated” or “continuous” watts. That’s the maximum power the generator will put out on an extended basis. And it’s the only rating you should rely on when buying a generator. The higher “maximum” or “starting” rating refers to how much extra power the generator can put out for a few seconds when an electric motor—like the one in your fridge or furnace—starts up. If you buy a generator based on the higher rating and think you can run it at that level, think again. It will work for a little while. But by the end of the day, your new generator will be a molten mass of yard art, and you’ll be out shopping for a replacement.
Stock Up On Oil and Filters
Most new generators need their first oil change after just 25 hours. Beyond that, you’ll have to dump the old stuff and refill every 50 or 60 hours. So you need to store up enough oil and factory filters to last a few days (at least!). Running around town searching for the right oil and filter is the last thing you want to be doing right after a big storm.
Chill Out Before You Refill
Generator fuel tanks are always on top of the engine so they can “gravity-feed” gas to the carburetor. But that setup can quickly turn into a disaster if you spill gas when refueling a hot generator. Think about it—spilled gas on a hot engine, and you’re standing there holding a gas can. Talk about an inferno! It’s no wonder generators (and owners) go up in flames every year from that mistake. You can survive without power for a measly 15 minutes, so let the engine cool before you pour. Spilling is especially likely if you refill at night without a flashlight.
Running Out Of Gas Can Cost You
Some generators, especially low-cost models, can be damaged by running out of gas. They keep putting out power while coming to a stop, and the electrical load in your house drains the magnetic field from the generator coils. When you restart, the generator will run fine, but it won’t generate power. You’ll have to haul it into a repair shop, where you’ll pay about $40 to reenergize the generator coils. So keep the tank filled and always remove the electrical load before you shut down.
Old Fuel is Your Worst Enemy
Stale fuel is the No. 1 cause of generator starting problems. Manufacturers advise adding fuel stabilizer to the gas to minimize fuel breakdown, varnish and gum buildup. But it’s no guarantee against problems. Repair shops recommend emptying the fuel tank and the carburetor once you’re past storm season. If your carburetor has a drain, wait for the engine to cool before draining. If not, empty the tank and then run the generator until it’s out of gas. Always use fresh, stabilized gas in your generator.
The Internet is full of articles explaining how to “backfeed” power into your home’s wiring system with a “dual male-ended” extension cord. Some of our Field Editors have even admitted trying it (we’ll reprimand them). But backfeeding is illegal—and for good reason. It can (and does) kill family members, neighbors and power company linemen every year. In other words, it’s a terrible idea. If you really want to avoid running extension cords around your house, pony up for a transfer switch ($300). Then pay an electrician about $1,000 to install it. That’s the only safe alternative to multiple extension cords. Period.
Store Gasoline Safely
Most local residential fire codes limit how much gasoline you can store in your home or attached garage (usually 10 gallons or less). So you may be tempted to buy one large gas can to cut down on refill runs. Don’t. There’s no way you can pour 60 lbs. of gas without spilling. Plus, most generator tanks don’t hold that much, so you increase your chances of overfilling. Instead, buy two high-quality 5-gallon cans. While you’re at it, consider spending more for a high-quality steel gas can with a trigger control valve (Justrite No. 7250130; through our affiliation with amazon.com).
Lock It Down
The only thing worse than the rumbling sound of an engine outside your bedroom window is the sound of silence after someone steals your expensive generator. Combine security and electrical safety by digging a hole and sinking a grounding rod and an eye bolt in concrete. Encase the whole thing in 4-in. ABS or PVC drainpipe, with a screw-on cleanout fitting. Spray-paint the lid green so it blends in with your lawn. If you don’t want to sink a permanent concrete pier, at least screw in ground anchors (four anchors; No. WI652775; from globalindustrial.com) to secure the chain.
Close-up of concrete pier, eyebolt and grounding rod
Connect the ground wire to the grounding rod for safety and the chain to the eyebolt for security.
Use a Heavy-Duty Cord
Generators are loud, so most people park them as far away from the house as possible. (Be considerate of your neighbors, though.) That’s OK as long as you use heavy-duty 12-gauge cords and limit the run to 100 ft. Lighter cords or longer runs mean more voltage drop. And decreased voltage can cause premature appliance motor burnout.
More information available on our site:
- Storms do more than cause power outages. Search for “disasters” and check out our prevention tips.
- Small-engine frustration? Search for “start up tips” and get running.
- Survive any weather in a reinforced room. Search for “storm shelter.”
Real World Advice From Our Field Editors
Exercise your generator
“I start my generator up every three months as recommended by the manufacturer and let it run for about 20 minutes to charge the battery for my electric starter.” – Larry Meacham
Build a generator garage
“For a portable generator, we poured a small concrete pad and basically built a doghouse over the unit that is hinged to the pad. It worked better than a blue tarp.” – Al Cecil
A door for cords
“Most people run extension cords into the house through an open window or door. But our fireplace has a small cleanout door on the outside, so I run extension cords through it.” – Charles Crocker
Unplug the freezer
“Freezers and fridges are power hogs. But you can disconnect them from your generator and free up power for other stuff. First, turn the temperature settings way down. When they reach the lower temperature, unplug them and don’t open their doors unless you have to. They’ll act like coolers and stay cold for a long time. Freezers usually will keep food frozen about 24 hours. During that time, the generator is free to power tools or your big-screen TV.” – Rick Granger