One of the most commonly asked questions regarding generator troubleshooting is “Why does my generator run for a short period of time, and then shut off?”  We asked our most experienced technicians this question and they came up with quite a few of the most common reasons this may be happening and what you can do to remedy them.

Overload

• The first thing you should check is that you are not running more equipment on backup power than your generator can handle. If you are running too much equipment on too small of a generator, the generator may shut down in order to avoid putting too much stress on your appliances.
• The only way to remedy a loss of power due to overload is to shut off the generator, reduce the load by unplugging unneeded appliances, and restart the generator. If you need help properly sizing your generator, check out the EMC Generator Sizing Webinar.

Fuel Shutoff Valve is Closed (Portable Generators)

• If you are using a portable generator, there is a fuel shutoff valve that is usually only used when you are storing your generator for long period of time to prevent stale fuel from circulating unnecessarily.  Check that this valve is not still shut and preventing the flow of fuel to your engine.
• To remedy this, simply open the valve and restart the generator.

Fuel Level Too Low

• Obviously, your generator will not run without fuel. If your generator only ran for a short period of time then won’t start again, make sure you check your fuel level.
• To remedy low fuel, always make sure the fuel tank is full before running your generator. You can also choose to install a generator that is fueled by natural gas or liquid propane straight from the utility to prevent lack of fuel (disregarding extreme circumstances where the utility may fail).

Oil Level Too Low

• Oil levels that are too low can cause generator shutoff. Generators will still start with low oil, but newer models have a “low oil shutoff sensor” that will automatically kill the engine when oil levels are too low in order to prevent running of the generator with no oil. Running with low or no oil can cause severe wear and destruction to certain parts of your engine.
• To remedy low oil level, check oil level with the dipstick. If oil looks clean but the level is low, add more oil. If oil is dirty and at a low level, an oil change is necessary.
• Sometimes your generator may display a low oil pressure alert when the pressure is actually fine. This may indicate that your oil pressure sensor is faulty and needs to be replaced.

Water Level Too Low

• The rise in temperature without proper water levels in the radiator is too much for most generators to handle. Running at a high temp for any period of time is hard for the most sensitive parts of the engine, control panel, and voltage meter.
• Check water level and add water if necessary.

Choke Position Open for Too Long (Portable Generators)

• To start the generator the choke needs to be in full choke position.  After a few minutes, change it to half, then after a few more minutes change it to run.
• Generators can shut off after a few minutes of running if the choke is left in the full choke position for too long.

Rodents

• Generators are a warm home for small animals. And when they can’t find enough food, they will chew on any exposed wires or hoses causing electrical issues or fluid leaks.
• To remedy rodent infestations, remove the rodents and replace any wires or hoses that have been chewed through. Setting rodent traps to catch any future small animals before they make a home in your expensive generator may be a good idea as well.

Faulty/Dirty Spark Plugs

• If you have an issue with dirty or faulty spark plugs, you may hear a crackling noise and see your generator shut down after only a few seconds of running.
• To fix a spark plug issue, the most foolproof way would be to replace them with brand new ones. However, some spark plugs can become dirty and work like new if cleaned and re-installed.

Clogged Air Filter

• Engines need clean air to circulate in order for all parts to work in harmony. A clogged air filter prevents the correct amount of clean air from circulating throughout the engine.
• This fix is easy. Clean or replace your air filter for better air circulation.

Dirty Fuel Tank/Pipes

• Pressure can get locked in your fuel tank, dust or debris can cause restrictions, or your pipes can become damaged and leak. This makes it hard for the proper amount of fuel to circulate.
• To remedy a fuel system issue, first start with checking the fuel cap vent for any clogs. If all looks well with the fuel cap; check the fuel tank for sediment, bad fuel, etc. (See our article on maintaining diesel fuel here!)  If the fuel tank looks dirty, cleaning the fuel tank and conditioning the fuel is a good idea. It is also a good idea to release pressure in the fuel tank and inspect all the pipes before each use.

Dirty Carburetor

• Bad fuel in the carburetor can cause the volatile ingredients from fuel evaporate from the accumulated gas in the carburetor to form a thick mixture that sticks in the carb and causes a disruption in the fuel supply.
• The easiest way to remedy this is to keep your carburetor clean. If a carburetor is left dirty for too long, you may need to end up replacing the carburetor.

Battery Issues

• Usually battery issues begin with your battery charger. Your charger could be faulty, your installer could have put the charger on the same circuit as the block heater (causing the breaker to trip), or you could have gotten a faulty battery.
• Check the battery charging source to make sure it is not faulty. It may need to be replaced. If charger is not faulty check circuitry for overload. If circuits are not overloaded and the charger is working as it should, then you should replace the battery.

Block Heater Issues

• Block heaters keep the liquid in your engine around 100-120^oF. This allows for quick startup and lubrication of critical parts. If your block heater is faulty, your generator may try to start, then shut off due to lack of fluid circulation, especially in colder temperatures.
• The only way to fix this problem is to install a new block heater.

Engine Fault

• Engine fault is hard to diagnose when you are not an experienced technician. If you have tried all the above steps and your generator still will not run for extended periods of time, engine fault may be the culprit.
• If you suspect engine fault, the best idea is to call an experienced technician to come take a look.

Exhaust System Fault

• A fault in the exhaust system can cause a generator to fail after a few minutes due to a buildup of exhaust causing a fault in the noxious emission sensors.
• This is a critical issue that needs to be dealt with by a professional.

Electrical Problems

• Electrical problems can happen in any part of any circuit or wiring of your generator. Electrical issues are not to be dealt with by unexperienced laypeople.
• This issue needs an experienced technician or electrician to come and troubleshoot.

Sensor Failure

• Newer generator models have a lot of sensors. Sometimes if one sensor is failing it can set off a cascade of other issues in other sensors. Usually sensors are the most expensive part of a generator to repair or replace.
• The only way to fix a faulty sensor is to replace it. After replacing the sensor, the control panel may need to be reprogrammed to acknowledge any changes made before it will start working correctly. An experienced generator technician can help with any sensor replacements or reprogramming.

Are You Having Problems With Your Generator? We Can Help!

Call 800-595-5315 Or Connect With Our Expert Technicians Here:

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Conrad Petersen

Lead Generator Technician

Conrad has over 10 years of experience in power generation. He graduated from Universal Technical Institute, and has a master certification from Generac. He loves the great outdoors and spending his time camping and fishing.

As with any piece of mechanical equipment, standby generators are subject to wear, tear, and breakdown. But if after a few decades your generator isn’t having outward or obvious signs of degradation, when should you purchase a replacement? In this article we will go over six signs that may indicate it is time to replace your generator.

1. It Has Been In Service for a Long Time

Depending on the quality and size of your standby generator, most manufacturers usually predict that a standby generator will remain reliable anywhere from 10,000 – 30,000 running hours (about 25 – 40 years) depending on how well it is maintained. If maintained properly, the less you use your generator, the longer it will last. Even if it seems like your generator is still running strong after 40 years of light use, there are likely unseen internal parts that are well worn down and on the verge of breaking, you won’t be producing the same amount and quality of power that you were when the generator was first installed, and a critical failure may be right around the corner.

2. It Is No Longer the Correct Size for Your Needs

With any new business or home, predicting load growth is a tricky process. You could begin your business or move into a new home with one set of power needs, and then things could quickly evolve into a whole new set of circumstances. Whether your home or business is shrinking or growing, you need to be aware of the load being transferred to your generator when utility power fails. If your generator is too big for your load, carbon deposits could be building up in your gen without you even noticing. If this continues to occur for too long without intervention, your generators’ power producing capabilities will be greatly reduced. If your generator is too small for your load, the generator is more likely to fail or even overheat when power is transferred.

Revisiting your power producing requirements is a good idea, at least every time your power needs change within your home or business. If you notice your generator is not properly sized for your requirements, replacing your generator with a properly sized one is recommended for optimal power production.

3. It is Showing Signs of Wear

Even with proper maintenance and storage, wear and tear is a natural part of any machines’ lifespan. If you have not been performing routine maintenance or if your generator is exposed to the elements, wear will occur much faster, thereby shortening the lifespan of your generator significantly. Biannual maintenance and continuous sheltering of your generator from weather, dust, and debris can greatly increase the amount of time your generator will remain a reliable source of backup power for your home or business. If any part of your generator starts showing signs of excessive rust, it is time for a new generator.

4. It is No Longer Reliable

If your generator develops problems starting on demand or you notice you are calling the repair man more than normal; it’s time to buy a new generator. The main reason you purchase a standby generator is to provide backup power during a utility outage, so if your generator has problems starting during an outage, there is no way to know if you can rely on the power to be provided when you are not there to remedy any issues with starting.

5. It Uses Outdated Technology

Technology is ever evolving and things are upgrading at an increasingly rapid speed. What was state of the art ten years ago, is now outdated and seems like it was invented in the Stone Age. Generators are finely tuned machines that will only get more intricate and tech heavy as time goes on. If your generator is no longer supported by the manufacturer, or the technology is no longer able to be updated for your specific model; that may be a good indication that it is time for an upgrade.

6. Updated Ecological Interests

Air quality regulations are ever changing, and trending toward becoming more strict. With climate change happening at an ever increasing rate, our government has increased the laws surrounding diesel and natural gas generators. As generators age, they start to consume excessive fuel and have high levels of carbon monoxide output which, according to scientific research, is detrimental to the environment. If you start to notice either of these symptoms beginning to emerge, chances are your generator is not up to date with the current environmental standards for power generation equipment and should be replaced.

Got More Generator Questions? We Can Help!

Call 800-595-5315 Or Connect With Our Expert Technicians Here:

Other Articles

• 
  Critical Spare PlanningFebruary 22, 2023
• 
  Where Do I Start On My Generator Installation?September 13, 2022
• 
  How can Las Vegas heat lead to generator failures?August 18, 2022

Conrad Petersen

Lead Generator Technician

Conrad has over 10 years of experience in power generation. He graduated from Universal Technical Institute, and has a master certification from Generac. He loves the great outdoors and spending his time camping and fishing.