Generac Generator How to & Troubleshooting Guide

Generac generators are designed to provide maximum power with maximum portability. However, the generator may not perform optimally if it suffers from serious issues, such as overheating, tripped circuit breakers, or a wrongly configured fuel valve.

Keep reading to learn how to troubleshoot and fix your Generac generator.

Why won’t my generator turn on?

Below are some reasons why your generator won’t start and what you can do to restore power to your home.

The Fuel Tank Is Low

Your fuel should be the first thing you check. If your generator uses gasoline, check the fuel levels in the tank and add more fuel if the levels are low. For a propane-fuelled generator, check the fuel level and ensure all the valves and tubing connecting the propane tank to the generator are open.

Regarding gasoline-powered generators, keep in mind that “stale” gasoline, any gas more than two months old, can damage the generator’s engine. Drain stale gasoline from the fuel tank and the carburetor, then fill the tank with fresh gasoline.

Low Oil Levels in the Engine

Oil is vital to your generator’s engines. While most generators have a sensor to let you know when oil levels run low, it is still essential to check the oil levels with a dipstick. If you have low oil, refill with the right type of oil as directed by the manufacturer. This could be an excellent time to replace the oil filter to keep your generator in good condition and avoid costly breakdowns and emergency repairs.

Dead Battery

If your generator doesn’t start, it could be due to a dead battery or faulty connections. Try charging the battery via a 12-volt DC outlet or give it a jump courtesy of your car battery. If that doesn’t work, the battery is not likely the problem.

Cables Are Plugged into the generator

When you try to start your generator, first check that nothing is plugged into it. Even if the cords plugged in have no appliances connected to them, unplug everything to isolate why your generator won’t start.

Adjust the Choke Control

The choke regulates the air levels within the carburetor when the engine starts up. If the motor cannot turn over, the amount of air mixing with the fuel may be the problem.

A cold engine should have the choke closed completely. Then, once the engine starts to warm up, you can adjust the choke to open fully. However, if the engine is still warm, the choke needs to be halfway open before restarting the engine.

Clogged Air Filter

If you adjust the choke and it seems to help but doesn’t completely resolve the problem, check the air filter. A clogged air filter prevents the carburetor from getting the air needed for combustion. You can see the air filter easily, and if it looks dirty, replace it and move the choke back to closed.

Dirty Spark Plug

If you’ve reached this point and the engine will not turn over, the spark plug may be dirty. Start by removing the spark plug from its socket. Replace your spark plug if:

  • It is covered with dirt or debris that you cannot brush off
  • There are any signs of broken electrodes or cracked

If you can remove the debris, clean the spark plug carefully and follow the generator owner’s manual to adjust the electrode gap. Hold it against the engine’s crankcase and pull the generator’s recoil starter to check the spark plug. If the spark plug is working, you will see blue sparks. Reinstall the spark plug and try starting the generator again.

Clogged Carburetor

You may have already drained the carburetor earlier when you checked for stale gasoline, but if not, now is the time to do it. Old gasoline forms a clog in the carburetor, preventing new fuel from getting through to initiate combustion.

To clean out your carburetor, start by closing the fuel valve. Next, remove the bowl at the bottom of the carburetor and use a brush or towels to clean out any debris. Next, insert a needle or straight pin to remove clogs from a brass jet nozzle. Once you’ve finished, turn the fuel valve back on before attempting to restart the generator.

Clogged Fuel Valve

If the carburetor is clogged, the fuel valve is also clogged. Check to ensure that the fuel and vacuum relief valves above the generator’s gas tank are open. If your generator still won’t start, unplug the fuel hose and check if gasoline can flow through the fuel line. Have a bucket handy to catch the fuel when you try this.

Also, check for clogs in the filter between the fuel valve and carburetor.

Oil Level Sensor Malfunctioning

The low oil sensor lets you know when your engine’s oil levels are too low. However, if the sensor malfunctions, you will not if the oil levels are low. Also, if you run your generator on an uneven surface, the oil level will be uneven, and the sensor may misread it as low.

Position your generator on an even surface. If the oil sensor still reads low, disconnect the sensor and try running the engine. If it starts, your oil sensor is at fault. Plugging it back in should reboot it, but if not, you will need to replace the sensor.

Why is my Generac generator running but not generating power?

Here are the reasons why your generator is not generating power and how to fix it;

Tripped Breaker

First and foremost, if you’re not getting power to your appliances after you’ve turned on the AC power switch from your generator, you should check to verify that you don’t have a tripped breaker.

There are two types of breakers that you might encounter:

  1. Circuit Breaker (fuses)
  2. GFCI Breaker

The circuit breakers will protect you from overloading the amp capacity of the generator. For example, if you have a 1kw generator and decide to try to power a microwave, you will trip a circuit breaker (and hope that that’s all the damage that you do).

GFCI breakers are designed to trip when they sense that there isn’t enough power to complete the circuit on the circuit’s designated route. They are programmed to sense a certain amount of power. If that power deviates from the norm, it trips and saves you from being shocked.

Another common way to trip circuit breakers is to use the wrong gauge of wire for what you’re trying to power or plug multiple cords together.

Remember that it might just be a particular item tripping your breaker, and it might not necessarily have anything to do with your generator. So test other items out and even items of comparable wattage to see if the affected breaker still trips.

If it is a true emergency and you cannot get a generator to work, and you are certain that the breaker is at fault, you can technically bypass your breaker altogether. 

Bad Outlet

With the generator running, ensure the AC power is turned on, and the breaker is not tripped. Use a multimeter to measure the AC voltage by placing the black lead in the smaller slot on the right (of a 120v outlet) and the red lead in the longer slot on the left. If you are not getting any reading, you might have a bad outlet. Replace if necessary.

Check this too: California Generator Ban: What Does it Mean to RVers and Offgrid Dwellers

Loss of Residual Magnetism in the Alternator

Once you’ve verified that your breakers are not the problem, the next thing to do is see if you’ve got a loss of residual magnetism in your alternator. Like those in your generator’s alternator, Electromagnets need a bit of residual magnetism to be “primed” to get the electrical generation process going. 

There are a few things that lead to the loss of residual magnetism;

  1. Lack of use can cause a generator to lose residual magnetism. Over time the reserve of magnetism is slowly depleted. Until it eventually runs out.
  2. You keep things plugged into the generator when you turn it off. So if the generator is powering a load when turned off, its magnetism will be sucked into the load.
  3. You leave the generator running for too long without plugging it into anything. This can cause the electromagnetic field within the generator to shut down.

How to restore residual magnetism in a Generator

These are two main methods for restoring a generator’s residual magnetism;

12 Volt Generator Battery Method

Locate the voltage regulator for your generator. Unplug the two wires that connect to the generator brushes. Usually, one is red, and the other is black or white. Connect the black or white to the generator ground battery terminal.

Plug in a light, turn on the generator breaker or switch, and start the motor. Connect the battery +12 volts red cable to the red wire on the terminals you removed for three seconds.

Remove your wires and replace the plug. The generator should now be producing power again. Make sure you unplug the brush wires from the automatic voltage regulator, or you will damage the regulator.

Safety Tip: Do not contact the voltage regulator or other wires as dangerous voltages may be present that can cause electric shock.

2. Electric Drill Method

Plug an electric drill into the generator receptacle. If the drill is reversible, move the direction switch to the forward position. Then, start the generator while depressing the trigger on the drill.

Spin the drill chuck in the reverse direction. This will excite the field, and the generator will now produce electricity. If turning the chuck in one direction does not work, try spinning the chuck in the other direction, as you may have the reverse switch positioned backward.

Use caution not to get your hand or other materials caught in the chuck. As soon as the field is exited, the generator will produce power, and the drill will turn on.

Note: If these methods do not help you restore generator output power, replace the Automatic Voltage Regulator as it may be damaged.

Worn Brushes

This is pretty much the last thing you can easily check visually without learning how to use a multimeter to check resistance and voltages. When you remove the cover to your generator’s alternator, you will see something relatively similar to what’s in the picture.

Remove the bolts holding the alternator cover in place. The black brushes stick out of the gray plastic housing and are spring-loaded (you can push them into the gray housing, and they’ll pop back out). If they are deformed or damaged, you’ll need to replace them.

Usually, right above the bearing, you will see two spade connectors that connect to the brushes made from carbon material that makes contact with the rotor. They are held in place by a screw.

With the generator off, take a picture of how everything looks. And the orientation of the wires and remove the spade connectors. Then, remove the screw. 

Pull out the brush assembly and check to see if they look damaged, broken, or are sticking. The brushes are small rectangular carbon pieces that can be pushed into the assembly but want to pop back out. 

Check the assembly itself for any burn marks or anything that doesn’t look right.   Your brushes are likely fine, but if they aren’t, go ahead and replace them.

How much does a Generac generator cost?

Generac generators cost $2,000 to $5,000 for a 7 to 24 kW whole-house unit, plus $3,000 to $5,000 for installation. The total cost can be around $12,000 to $15,000 to buy and install a whole-house Generac generator. Home Depot and Lowes offer financing options for their generator installation services, but interest can increase the total cost you pay.

How much does it cost to install a Generac automatic generator?

Home generator installation usually costs about 75% of the cost of the generator. The installation process requires a lot of experienced labor and electrical rewiring. Installation costs vary based on the setup of your home. The lowest installation cost can be obtained when the electric meter and gas meter are located on the same side of the home.

The cost will increase if the generator and meters are located further apart.

Estimated installation costs include;

Handyman payment to build a platform for the generator: – $500-$1000

Plumbing costs to connect the gas line: – $1500-$2500

Electrical panel upgrade cost including supplies: – $2800-$3500

How long can a Generac generator run non-stop?

A standby generator can run for up to 3,000 hours, powering a medium-sized home, though it is recommended you do not run a generator for longer than 500 hours continuously.

If your generator runs on propane or gas, be prepared by ensuring that you have plenty of fuel on hand to keep your generator running for as long as you need. Once you run out of fuel, even the most powerful and reliable generator won’t be able to help you. There are 24, 48, and 72-hour tanks available.

If your Generac generator uses liquid propane stored in a tank, running times are not indefinite but still considerable. Most standard tanks contain anywhere from 250 to 1,000 gallons. Typical home-use will burn around 2 to 3 gallons of propane an hour. So a 1,000-gallon tank will see you through around two weeks of outages.

Diesel tanks for home generators come in a variety of sizes. Sub-base tanks usually store less than 1,000 gallons of fuel, while underground storage tanks have options for more than 1,000 gallons. You can also get above-ground tanks, though these usually require planning permission and do not come in such high capacities.

A generator producing 10 kW at around half load will consume around 0.35 gallons of diesel per hour, implying that a 1,000-gallon tank will last approximately 17 weeks.

Note: Monitor the generator’s oil consumption to ensure that it isn’t running low. If you are using your generator for long periods, it is good to shut it down every 24 hours, let it cool, and add oil if necessary.

Why is my Generac backup generator still running even when there is electricity?

This is normal as most emergency generators are designed to continue running for a few minutes after power is restored to ensure that the flow of electricity from the utility company is continuous and stable.

However, if it still keeps going even when electricity is fully restored, it could be malfunctioning due to several reasons;

The AMF panel

It might be that the changeover panel has switched back over to mains, and the generator is just running through its cool-down period. This is a preset time and is generally around 5 minutes. Have a look at the AMF panel to see whether the generator or the mains power your load.

The Mains’ power is still not yet within acceptable limits

After a power cut, it is common for the mains to come back but not be quite within the acceptable range. For example, you may have 230V on L1, but you could have 180V on L2 and 0V on L3. This is because most changeover panels monitor all 3 phases.

The changeover panel may have realized that the mains power is still incorrect and will continue to run on the generator to keep your operations working. If your AMF panel has a display, you can check the voltages of all three phases on the mains. And the frequency and this will highlight whether the mains is there or not.

AMF Reset

Sometimes the changeover panel needs a reset to realize that the mains power has been restored. This doesn’t happen often, but it can happen.

When your generator is powering your building, monitoring the mains’ voltages is good to see whether the mains have been restored.

How to reset a Generac generator

To reset your generator;

  • Switch controller to OFF – press the OFF button
  • Remove service end of generator for access to the battery compartment
  • Disconnect the negative ( black ) battery terminal
  • Disconnect T1 connector
  • Wait 15 seconds, reconnect the T1 connector and then reconnect and tighten the negative battery terminal
  • Re-install generator side panel

All Generac generator error codes, their meaning, and fixes

Overspeed, Code 1200/1205

This code usually displays when the controller detects high RPM. However, defective ignition coils can cause this, and for this, you need to contact an authorized service dealer.

Underspeed, Code 1600

This code can be set off when your controller does not detect the correct RPM. If your unit is displaying this code, contact an authorized service dealer.

Undervoltage, Code 1900

A sudden voltage drop can set off this error code. For this code, a service call is needed.

Overload, Code 2100

Your unit shows this code when your controller senses an overload condition. The first thing to do is remove the load. Load shedding should be installed to prevent this from happening in the future. If you remove the load and the problem persists, a service call is needed.

Low Battery

Check the VDC on the battery and the controller to make sure they are the same. If the voltage is less than 12.5 VDC, recharge the battery. If the voltage is over 12.5 VDC, check the charge circuit for operation.

RPM Sense Loss, Code 1505/1515

RPM Sense loss is a common fault indicated by the code 1505/1515. If this fault arises, it usually means there are internal issues or a problem with the fuel supply. For code 1505, the RPM alarm is set when a 2-cylinder unit is cranking, and for code 1515, the RPM alarm is set when a single-cylinder unit is cranking.

Both codes are caused when the controller told the engine to crank but did not get a signal back that the engine was turning. Possible causes for both codes are a dead or bad battery, a bad starter or wiring to the starter, or ignition coil problems. If the unit is running and shuts down, attempting to restart, clear the alarm by pressing the ENTER button twice, then press AUTO. 

Next, remove some of the loads. Next, try putting it back in AUTO and then restart. If it does not start after doing this, you will need to place a service call. If the unit will not start in AUTO when there is utility loss, clear the alarm by pressing the ENTER button twice, then press AUTO.

Then, using the control panel, check the battery. To do this, navigate to the BATTERY MENU option from the MAIN MENU. If it states ‘check battery,’ try replacing the battery. Contact an authorized service dealer if it states that your battery is ‘good’ when being checked.

Low Oil Pressure, Code 1300

The fault code 1300 indicates low oil or low oil pressure. When your home standby displays this error, the first thing to check is your oil level. If oil is needed, add oil per recommendations in your owner’s manual. Be careful not to overfill the engine. If the oil level is good and your unit is still not working, a service call is needed.

Other possible causes could be the low oil pressure switch being faulty. In this case, the oil pressure should be checked and the switch replaced. There is also possibly an internal problem with the engine not building oil pressure. Again, this would require an oil pressure test to verify.

High Temperature, Code 1400

High temperature is indicated by fault code 1400. If this fault occurs, the high engine temperature switch has closed and shut down the unit for exceeding the engine temperature limit. The unit should be checked for debris blocking the vents that might be restricting airflow. The high temp switch and its wiring should be checked if nothing is found.

Overcrank, Code 1100

The code means that the controller is telling the engine to start, but it cannot start for some reason. The controller has verified that the engine is cranking but not starting. This is most likely a fuel or maintenance-related issue.

If your home standby is displaying this error code, resetting the controller and restarting your unit may do the trick. If your unit does not start after two automatic attempts, there is an issue. Make sure the gas to your generator is turned on. Your gas is on if the handle is lined up with the pipe.

If your handle is lined across the pipe, the gas is turned off. If the gas is on and your unit is still not working or is running rough, contact an authorized service dealer.

How to clean and maintain a Generac generator

Below are the key components of a generator that must be cleaned and maintained for optimal performance;

Spark Plugs

Combustion engines can’t work or operate correctly without an adequate spark to ignite the fuel source. Since spark plugs play a critical role in your backup generator being able to run, especially during power outages, it’s always a good idea to inspect them when doing an oil change to see if there’s excessive carbon build-up, fractured tips, proper gapping, or appear to be in bad shape.

All standby generators should have annual inspections of their spark plugs at a minimum to ensure they’re clean and firing properly. They should be replaced if they appear to be in poor shape.

Filters

When your generator is going through an oil change, change the oil filter during the process since the old filter will frequently have metal fragments and other impurities that can cause damage to the unit if not changed. Reused oil filters can also shorten the generator’s lifespan, which makes your overall investment in the generator more costly in the long run.

Fuel filters should also be inspected and replaced if they’re old, brittle, or appear dirty. Unlike oil filters, fuel filters only need to be replaced as needed during inspection

All combustion engines must take in the fresh air, so be sure your Generac generator’s air filter is looked at during inspections and general maintenance. Replace it if the air filter is filled with debris or appears generally dirty. If your generator can’t take in the fresh air, it can’t properly function or may even fail when it’s most needed.

Batteries

Generac generators used for home and commercial applications have only one large battery with a connected charger to extend the battery’s lifespan.

While going through the inspection process, evaluate the battery and charger unit to ensure ample amperage from the battery source. If it’s found the charger isn’t doing its job or the battery amperage is low, it is vital to replace them right away.

Remember, a drained battery or dying charger may lead to your generator not being able to start or work at all.

Gas Regulators

Your fuel regulator is another key component of the Generac Home Stand By Generator system, and they need to be evaluated regularly as well. Items such as diaphragms, fittings, and gaskets tend to be the weak points in fuel systems and may cause serious issues leading to an inoperable unit.

Annual Oil Changes

Combustion engines are what power backup generators, and just like any other combustion engine out there, Generac generators need to have regular oil changes to keep them operating optimally.

Other items that should be inspected and maintained or replaced include:

  • Coolant and radiator (if your unit is liquid-cooled)
  • Alternator (if equipped)
  • Transfer Switch(es)

How much does it cost to service a Generac generator?

Generac generators require annual maintenance. Generac offers a $200 annual service contract that covers the yearly checks, but some Generac installation professionals offer less expensive options at $170 per check-up.

Depending on the generator you have and the checks carried out, you can expect annual generator maintenance costs to be around $150 to $300.

How often should I exercise my Generac generator?

As a general rule, a generator should be exercised without a load between once a week and once a month. Testing with a load should be done on a monthly or quarterly basis. Your generator’s exercise cycle may be automated by a timer, which ensures the generator is tested regularly.

How to reset the red light on a Generac generator

The RED light indicates that the unit is in fault mode and will not run. To clear the red light on the generator, you have to fix the problem to clear the error code. If you remedy the problem and the red light does not turn off, do the following;

  • Start by removing the top cover and finding the ‘Manual/Auto/Off’ control.
  • Select ‘OFF’ and press enter to clear the error code.
  • Once you select ‘Auto,’ the generator will start within the next ten seconds.

If this does not work, reset the red light as follows;

  • Turn the generator off by pressing the off button
  • Then hit on UP, UP, ESC, down, UP, ESC, up Enter buttons.
  • Navigate through the word dealer using the up button, then press “Enter.”
  • Check the dealer edit button
  • Using the up button, check for reset maintenance.
  • Press Enter
  • Press the ESC button till there is a blink in the display.
  • Press Enter
  • Hit on auto as this would return the unit into auto mode.
  • The display should be reading ready to run at this stage, and the status light indicates green

How to reset the yellow light on a Generac generator

For the Nexus or pre-Nexus 2008 style model, you can reset the light by going into the ‘Edit’ menu. Then use the +- keys or arrow keys (depending on the controller) to navigate the ‘Reset Maintenance’ option. Push ‘Enter’ then the arrow up to ‘Yes,’ then press ‘Enter’ again.

You can reset the light in other models by pressing the Enter key on the control panel. First, turn the machine off before resetting it. Then turn it back to Auto mode after the reset.

How often should I change the oil in my Generac generator?

Oil changes for Generac generators are needed only once a year but may require bi-annual changes if the generator exceeds 150 hours in a given period. Since generators exercise weekly in most cases, keeping track of hours used by your unit is key to understanding when the timing is right to get an oil change.

How to turn off a Generac generator

To turn off your generator;

  • Set the main utility disconnect found inside your house by the panel box to off.
  • Turn the outside disconnect off. The outside disconnect is located next to or near the generator and looks like a typical air conditioner disconnect.
  • Don’t rush the process. Instead, allow your generator to cool down for at least a minute before completely shutting it down.
  • At the controller on the generator, turn the setting off.
  • Locate and remove the 7.5-amp fuse from the controller. Removing this fuse will ensure that an accidental startup won’t occur during maintenance.

Here are additional ways to turn off your generator;

1. Turn the Knob or Switch on Your Generator to OFF

Whether portable or stationary, every generator has a knob or switch that says ON, Manual, or OFF. Turn this switch to the OFF position to start the shutdown process on your generator. The generator will then turn off on its own.

2. Flip the Breaker Inside Your House that Controls the Generator to OFF

The main panel box inside your house that feeds electricity to your entire home will have a GENERATOR breaker slot. This breaker is in the ON position by default. It’s in the ON position to ensure your generator will turn on during a power outage. To turn your generator off, flip the breaker to the OFF position.

3. Remove the Outside Disconnect or Turn the Disconnect Breaker to OFF

Your generator should have a disconnect just like an air conditioner or any other sizeable outdoor appliance. This disconnect is a safety measure designed for the emergency shutting down of machines. It will often come in a pull switch or a breaker panel. Flip the breaker or pull the disconnect out to turn off your generator.

4. Turn the Gas Flow Valve of Your Generator to OFF.

Closing the gas valve is the least recommended method of shutting down a generator and should only be used as a last resort. If you can’t locate any electrical components mentioned above to turn off your generator, turn the gas valve to the closed position on the pipe feeding your generator.

If installed properly, the gas valve should be next to the generator. If not here, then inside the house on the gas line feeding the generator. Turning this knob will take longer to turn the generator off as it will continue to use any residual gas, and it will also attempt to continue running even after you terminate the flow of gas. After two or three false starts, the generator will finally shut down.

5. Pull the Handle Inside Your House that Controls Power to the Generator

Most generator installers will install the unit with the addition of a transfer switch. This switch is essential to the proper operation of your generator, and you can use it to turn the generator off.

How to reset Generac generator after oil filter change

To reset the Maintenance Due light, set the Generator to OFF and press the OFF button to reset Maintenance Due. If an alarm condition exists, the alarm condition must be cleared prior to resetting the Maintenance Due light.

What is the difference between a portable generator and a Generac Generator?

These are the main differences between a portable generator and a standby generator like the Generac generator;

Portable Generators

  1. Portable generators are usually smaller in size and weight than whole-home generators.
  2. They are often transported to construction sites for operating power tools and campsites for powering RVs. However, because they are mobile, you can take them to any location where power is needed.
  3. Depending on a generator’s output, it can be used in a power outage to run small appliances around the home but not all appliances simultaneously. To connect to a portable generator, one must pick and choose the most necessary appliances during a power outage.
  4. Because portable generators usually run on gasoline or diesel fuel, the length of time they can operate depends upon the size of the fuel tank and the amount of fuel in storage. In a power outage, one must retrieve the generator and the fuel from its storage location and move it to the area where it is needed.
  5. Small appliances, tools, etc., can then be plugged into the generator via extension cords and removed when no longer necessary.

Best Use: Short-term or temporary use. Such as operating a few small appliances like space heaters or fans, a television or refrigerator, a range, power tools, or an RV.

Standby Generators like the Generac Generator

  1. Standby generators are stationary fixtures. They’re connected to your home or business’s electrical system and a fuel source, such as natural gas lines or propane tanks.
  2. The whole-home generator is automatically notified through the electrical system in a power outage. Then, it kicks on in seconds, powering on your furnace, kitchen appliances, television, lights, well pump, etc.
  3. Since standby generators vary in output, you can choose the appliances you need to operate most during an electrical outage, up to and including everything in your home.
  4. Because whole-home generators tap into a natural gas or propane source, you don’t have to trudge out into the cold to refuel the generator with smelly gas or diesel. Instead, the generator turns itself off when the electrical outage is over.
  5. Standby generators automatically provide hands-free operation throughout the year, even when you’re not there.

Best Use: Long-term daily use for operating many appliances at once, such as a well-pump, furnace or heat pump, refrigerator, TV, range, microwave, and lights.

How to Troubleshoot the Generac Generator

There are steps you can take to fix a faulty generator;

  • Check whether the generator is overheating; this will be indicated by the high-temperature light illuminating.
  • If the light is illuminated, unscrew the oil cap on the crankcase and pour a quart of the approved motor oil into the unit. This should be done after switching the unit off.
  • Ensure that the unit is properly configured for working use.
  • Often a problem can be a tripped circuit breaker, so check the AC receptacles on your Generac home generator to see if the button on the front is sticking out.
  • Push the button back in to reengage the circuit breaker.
  • Avoid automatic cut-offs from the generator by ensuring that the generator is on a level surface.
  • Place a spirit level on top of the Generac home generator and if it isn’t level, use a wooden block to redress the balance; an uneven surface can cause the generator to shut off automatically.
  • Adjust the fuel valve if the generator is running roughly.
  • Locate the fuel valve on the side of the unit and turn it to the “On” position.

Why does my Generac generator keep shutting off?

Here are the reasons why your generator runs for a short period then goes off;

1. Overload

There are many items that you should connect to your generator. If the things your generator should power consume more power than the generator can generate, expect it to go off after a short while. Therefore, always check if you run more items in the background than your generator can sustain. Also, if you run many things on a small generator, the generator can shut down to avoid impacting a lot of stress on the appliances.

You can solve the problem of losing power due to overload and shutting off the generator by reducing the appliances connected to the generator. Just unplug the appliances needed, then restart the generator. Check your generator’s manual if you do not know how much power your generator can create. The manual would also direct you on the appliances to connect.

2. The Fuel Shut-off Valve Could Be Closed

Your portable generator has a fuel shut-off valve typically used when storing it for a long time. This valve prevents stale fuel from circulating unnecessarily.

If this pipe is closed, your generator may run for a short period and stop. First, examine the fuel shut-off valve to ensure it is open and not hindering the flow of fuel to the engine. If your shut-off valve is closed, you can solve the issue by simply opening the valve and restarting the generator.

3. Fuel Level

Your generator needs fuel to run. Hence if there is little fuel, the generator would only run for a few minutes and stop. If you notice your generator ran only for a short period and would not restart, check on the fuel level.

To prevent this issue, make sure your generator fuel tank is always full before starting your generator. You can also go to a generator fuelled by natural gas or liquid propane directly from the utility to eliminate fuel issues. However, in extreme weather conditions, the utility can fail.

4. Oil Level

If the oil levels are too low, your generator can go off. Though generators can still start with low oil, new models have low oil shut-off sensors to shut off the engine automatically. Also, running the generator with no oil or low oil can wear and destroy various engine parts.

Check the oil level using a dipstick to prevent your generator shut from ting down due to low oil levels. If the oil appears clean and low level, add more oil. If the oil level is low but filthy, it’s best to change it altogether.

In some cases, your generator may indicate a low oil pressure alert when there is no issue with the pressure. If this is the case, your oil pressure could have a problem that you need to address immediately.

5. Low Water Levels

A high rise in temperature without enough water levels in the radiator can be too much for the generator to deal with. Hence always check the water level and add the necessary amount of water.

6. The Choke Position is Open for too Long

For portable generators, the choke needs to be placed in the full choke position for you to start the generator. After some minutes, you should turn the choke position to half, and after another few minutes, position it to run. If you leave the choke in full choke position for very long, the generator can run for a short period and shut off.

7. Rodents and Other Small Animals

The warmth generated by generators can attract various small animals. If these animals can’t find food, they will begin chewing any exposed wires or hoses, resulting in electrical issues or fluid leaks.

To solve the rodent and other small animals by investing in your generator wires, get rid of the rodents, and replace any chewed or destroyed wires. In addition, you can eliminate rodents and small animals by using traps or pesticides. For the pesticides, check with your local authorities for recommendations. 

You can always find ways to eliminate rodents in the future to prevent them from making a home in your expensive generators and destroying them.

8. Spark Plugs Could Be Dirty or Faulty

When the spark plugs are dirty or faulty, you will hear a cracking noise, and your generator may shut down after only a few seconds of running. You can solve this issue by replacing the spark plugs with new ones. However, if they are dirty, you should clean them.

9. Air Filter Could Be Clogged

Generator engines need clean air to circulate for every part to function well. A clogged air filter hinders enough clean air from spreading throughout the engine. The remedy for clogged air filters is cleaning or replacing your air filter for proper air circulation.

10. Fuel Tanks or Pipes are Dirty

Sometimes the pressure gets locked in your fuel tank, and dust or debris could cause restrictions, or the pipes can be damaged and cause a leak. As a result, it is difficult for the right amount of oil to circulate in the generator. Hence, dirty fuel tanks and pipes negatively affect the fuel system.

Check the fuel cap vent for any clogs to solve the fuel system issue. Check the fuel tank for sediment or the wrong fuel if everything is okay. 

Check if the fuel tank is dirty. If you notice any dirt or grime, clean the fuel tank and condition it. Also, release pressure in the fuel tank and examine all pipes to ensure they are in good condition.

11. Carburetor Issues

Bad fuel in the carburetor can make it dirty and cause volatile ingredients from fuel to evaporate. This can be attributed to accumulated gas in the carburetor making a thick mixture that sticks in the carburetor disrupting the fuel supply.

You can eliminate this issue by keeping the carburetor clean. However, if you leave the carburetor dirty for long, you’ll likely need to replace it soon.

12. Sensor Problem

The new models of Generac generators have many sensors. In some instances, if one sensor is faulty, it can affect or cause issues in other sensors. You can solve the faulty sensor issue by simply replacing it. However, replacing it is not enough as the control panel may not have detected the new changes.

You need to reprogram the control panel to acknowledge the changes made before putting the generator. This process can be challenging, especially if you do not have much experience handling sensors or reprogramming generator control panels. Hence it is good to call an experienced generator engineer.

If you do not replace a sensor immediately after it develops a fault, you risk replacing all of them since one faulty sensor can interfere with the rest. Besides, sensors are the most expensive components of a generator.

13. Electrical Issues

Electrical issues can make your generator run for a few minutes and then go off. They can happen in any part of any circuit or wiring of the generator.

Unless you are an experienced professional, it’s best not to fix electrical issues yourself. This is because they are complicated and dangerous and need experienced people only. It also requires an experienced electrician or technician to troubleshoot.

14. Engine Issues

An engine fault can also cause your generator to start and go off after a short time. However, this is not an issue you can diagnose yourself as it needs to be worked on by an experienced person. If you have accessed all the above suggestions and your generator continues to run and shut off after a short period, the engine could be having a fault. Hence call an experienced technician or a generator engineer.

Check this too: Backup Generator 101: Safe Set Up, How to & Troubleshooting

15. Battery Problems

Typically battery issues begin with a battery charger. The charger could be faulty; the installer could have put the changer on the same circuit as a heater, causing the breaker to trip. You could also have gotten a defective battery.

To solve this issue, check the battery charging issue to ascertain it is not faulty. If it is defective, then replace it. If the charger has no-fault, then check the circuitry for overload. You’ll likely have to replace the battery if the circuit is not overloaded and still experiences issues.

Oscar

In his spare time, Oscar loves tinkering with electronics. Solar panels, wiring, old TVs and sometimes DIY powerwalls. When he is not busy trying not to electrocute himself, you can find him in the garden tending to his vegetables and chickens.

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