Generator Failure - 9 Reasons Why Your Generator Won't Start

When you own a generator, it comes with the peace of mind of knowing that you are prepared for just about any emergency. You can take care of your family and loved ones, and you can even take your RV in the backwoods of nowhere if you really wanted to just get away for a while.

By the time you need your generator, it’s usually because there’s no other option for electricity. But when your generator won’t start in that important situation, you need to figure out the problem and get it up and going fast. Here are 9 reasons why your generator may not be starting to help you troubleshoot your generator failure.

Why Isn’t Your Generator Starting? Check These Tips Out First

Of course, there are always the obvious issues that you will want to check before you do anything else – kind of like making sure your computer is plugged in before you call tech support to tell them it won’t start.



Troubleshooting 101 for generators includes making sure, before you do anything else, that your generator has enough gas and oil to start, that the fuel valve is on, and that the choke is engaged. These three things are must-have basics for your generator to start, but if those are good to go and it’s still not firing up, keep reading for more troubleshooting tips.

Battery problems – If you haven’t used your generator in a while, the battery may have a buildup of lead sulfate. This means that it can’t hold a charge and can’t start your generator. You may be able to fix this enough to start your generator by cleaning the connections and tightening them, but your best bet is to replace the battery.

Fuel issues – Sometimes your fuel gauge can give a faulty reading, showing you that there is fuel when there’s not. Other times, your fuel may have degraded, especially if it’s diesel. Be sure to check the fuel regularly when your generator is not in use.

If you do have old or bad gas in your generator, it may look cloudy or separated. When this happens, you need to syphon out the old gas and replace it with fresh gas. To prevent this from happening again, always run your generator until it is dry or add fuel stabilizer to the existing gas in between use.

Lack of coolant – Coolant issues are a common reason why generators don’t start. You may have lost some of your coolants through unknown leaks, there may be a problem with the radiator keeping the coolant from cooling, or it’s just not flowing the way it’s supposed to and your generator’s sensors have shut the generator down to prevent bigger problems.

Coolant problems aren’t always easy to repair. Check your coolant for any dirt or other contaminants in them. If your coolant is leaking, it may show up in your oil as discoloration or it may have a milky feel to it. If you have a coolant issue, it may turn into an expensive fix. It’s best to avoid this situation by properly maintaining your generator when it’s not in use.

It’s not in the right position – Be sure your generator is set to run in auto, otherwise, if no one is around to start it, it may not protect your home and supplies as you intended. Refrigerators may warm and your food may spoil, you won’t be able to use your water or if you do, the pipes may break, and other problems can creep up without the backup of your generator. Keep your switch in the auto position instead of off/reset, and be sure the emergency stop button is not pressed.

Generator failure - 9 reasons why your generator won't start button

The spark plug is bad – The spark plug is one of the most important parts of firing up your generator. If it’s dirty, you may be able to use carb cleaner to gently cleanse it. Take the spark plug out of its position and spray carb cleaner into the cylinder, then replace the spark plug after it’s cleaned. If this still doesn’t work, you probably need a new spark plug.

Clogged air filter – Generators need airflow to be able to run smoothly. If your air filter is clogged, your generator may not start. This is a simple fix, though. You can pull the air filter out and see if it’s clogged. If it is just dirty, you may be able to just gently tap it against a surface to clean it off, but air filters are relatively inexpensive, so it’s a good idea to have extra on hand to just replace it.

Dirty carburetor – When old gas gets in the carburetor, it’s possible that it’s keeping your generator from starting. Carb cleaner may help, but if it doesn’t, you may need to remove your carburetor completely to clean it. This is a sensitive task, though. If you aren’t sure what you are doing, leave this to the experts.

Fuel line blocks – Fuel lines can easily be blocked through pinches, cracks, and leaks. You may be able to repair the problem by tracing it to the source, but it’s also just as easy to simply replace the fuel line itself.

The generator is bad – If you have checked all of the previous troubleshooting issues and your generator still will not start, it’s possible that you may just need to invest in a new generator. Any problems beyond those may be expensive to repair and you can find a new diesel generator for sale for comparable, reasonable prices.

Having a Generator on Hand is Always a Smart Idea

One of the first “extras” that you should invest in as a homeowner is a generator. Having one on hand in case of emergencies is a smart idea. As with accidents, you never plan an emergency, but it’s best to be prepared for them.

From hurricane power outages to simple electric failures, your home’s electricity is a tenuous thing. Keep the control in your hands by having a generator in easy access, and keep regular maintenance checks going throughout the year to avoid these 9 generator failures.