How to Fix a Pressure Washer That Won’t Start. What the Pros Say


Pressure washers are one of the useful tools to clean outdoor objects and surfaces with tough stains. Proper maintenance is essential to keep your machine in good working order. But even with good maintenance, you can pull the cord of your pressure washer, and you cannot start it. This can be due to multiple reasons, also depending on the type of pressure washer you have. A gas or electric pressure washer.

How to Fix a Pressure Washer That Won’t Start:

Generally, to fix an electric pressure washer that won’t start, check the fuse, the capacitor, the wall socket, and the extension cable. For gas pressure washers, check and clean the carburetor, the spark plug, and the air filter. Ensure that you do not use bad gas.

How to Fix a Pressure Washer That Won't Start. What the Pros Say 1

This article will show the common reasons that cause gas or electric pressure washers not to start. I will also show how to diagnose and fix the problem.

What Would Cause a Pressure Washer Not to Start? Some helpful tips

In general, if the fuse or capacitor of your electric pressure washer is damaged, it will not start. Gas pressure washers will not start if there is a carbon build-up on the spark plug’s electrodes. The carburetor or air filter is clogged. Another cause for a gas pressure washer not starting is a problem with the flywheel key.

We will not look into the various causes why a pressure washer will not start in more detail:

● Causes for an Electric Pressure Washer nor starting:

There are several reasons which prevent an electric pressure washer from starting. The most common are:

– Reason 1: Problem with the outlet or extension cable

The most common reason for an electric pressure washer not starting is a problem with the power outlet of the extension cable. Use another appliance, like a lamp, to check if the outlet is working fine. Do the same with the extension cord. This way, you know for sure that it is working fine. Always use a proper extension cord that is capable of delivering the power your pressure washer needs.

– Reason 2: Damaged Fuse

A damaged or blown fuse is another common reason for an electric pressure washer not to work.  Ensure that the voltage coming from the outlet and the extension cord is fine to run your pressure washer. A lower voltage will make your pressure washer pull more current, which can lead to a blown fuse.

To troubleshoot the fuse, use a multimeter. Remove the fuse and place the probes of the multimeter at the two ends of the fuse. Use the resistance setting. If the multimeter shows high resistance, it means that the fuse of your pressure washer is damaged and needs to be replaced.

The reason for a fuse failing can be moisture. But also using a long extension cord with a small gauge. Using such a long extension cable can cause a voltage. To keep the pressure washer working, the current will increase to compensate and cause the fuse to fail. If the cord is longer than 25 feet, then make sure to use an extension cable with 12-gauge wires. 

Reason 3: Damaged Capacitor

If the fuse of your pressure washer isn’t the issue, the next common reason for not starting is a damaged capacitor. The capacitor is located in your machine’s motor, and if it’s burned, the motor will not run. To check the capacitor, loosen the outer casing of the motor using a screwdriver. A bulging or blackening capacitor indicates it is damaged. To fix your pressure washer, remove the burned capacitor and replace it with a new one.

● Causes for Gas Pressure Washers not starting:

Gas pressure washers need more maintenance than electric pressure washers and have more parts that can cause them to fail to start. These are the most common causes:

– Reason 1: Damaged Spark Plug

A defective spark plug prevents the pressure washer from starting. Examine the spark plug wires. If they are loose, tighten them. Remove the spark plugs and check them. If you see any carbon build-up on the electrodes, it is a sign of a spark plug problem. The carbon build-up prevents the connection between the fuel and the electrode, and thus no spark. Meaning the pressure washer won’t start. You can remove this corrosion using a metal brush. If you can not really clean it, replace it. Sometimes, the porcelain insulator in the spark plug gets cracked. In that case, also replace it. Another issue that needs the spark plug to be replaced is damaged or burned electrodes.

– Reason 2: Air Filter

Your pressure washer may also not start because of a clogged air filter. The air filter is used to filter the dirt and bigger particles from the outside air before being used in the carburetor. If the air filter is clogged, it doesn’t allow enough air to the carburetor. The fuel-air mix will not be ok, and the engine will not start.

Remove and clean the air filter. A foam air filter can be washed with some hot water. A paper air filer always has to be replaced.

Also, check the vented fuel cap for clogs. This can keep the gas from reaching the carburetor. If it is dirty, clean it. To test if the fuel gap is the problem, start the engine without it. When it starts and runs fine, the fuel gap is the problem.

– Reason 3: Clogged Carburetor

The carburetor of your pressure washer also plays a vital role in the proper functioning of your machine. If the carburetor gets clogged, the pressure washer will not start and run. Bad gas can be one of the reasons for the carburetor to be clogged. Gas can go bad if you leave it in the tank and carburetor for an extended period. This can already be after a few months. Some of the gas will evaporate, leaving behind a sticky residue. This substance can clog the carburetor.

Clean the carburetor with some carb cleaner. You can do this by disassembling the carburetor or by cleaning it without removing it.

– Reason 4: Faulty Ignition Coil

If your pressure washer still isn’t starting, a faulty ignition coil can also be the reason. Use a spark tester to check the condition of the ignition coil.

– Reason 5: Flywheel Key

The flywheel is used as a safety precaution in a pressure washer gas engine. It protects the engine against any opposing force that causes the engine to stop. If you find the engine is difficult, or can not be started, inspect the flywheel by taking it off. Examine the key. If it is damaged, you need to replace it.

– Reason 6: Damaged Pump

If the pump of your pressure washer is damaged, you can not start it in a lot of cases. It can be because you are using the wrong type of pump oil, or you have used the pump without pump oil. Another reason can be dirt in the pump. These issues can damage the pressure washer pump such that it can not turn anymore. As the engine is connected to the pump, it may result in the engine not able to start.

You need to check if the pump can still turn. If you find that this is not possible, you have to remove it. Depending on the fault, the pump can be fixed. Or it needs replacing.

What Do You Do When Your Pressure Washer doesn’t Start?

The first step is to diagnose the problem. There can be an issue with the spark plug, the carburetor, the air filter, or the flywheel key for gas pressure washers. For an electric pressure washer wall socket, fuse and capacitor need to be checked. After diagnosing, the issue can be fixed.

If your pressure washer isn’t starting, first diagnose the issue with the steps shown earlier in this blog. A fix for some of the causes is already given there. Some others are added here:

● Fix 1 – Electric pressure washer: Repair or Replace the Fuse and Capacitor

To fix the pressure washer that won’t start, remove the fuse from the machine and examine it using a multimeter. If the multimeter gives a zero resistance reading, it means that your fuse is in working order. If not, replace it. Check the capacitor by removing the casing that covers the motor and examine it. A blacked capacitor indicates that it’s burned and needs replacement.

● Fix 2 – Gas pressure washer: Clean the Carburetor

If your pressure washer still isn’t starting, then clean the carburetor of your machine. I recommend taking some pictures or a short video during the process. You can use this when assembling it to know where the various parts are located.

Turn off the fuel valve, then access the carburetor by removing the throttle cover and air filter. Then remove the fuel pipe from the carburetor needle. Pull out the carburetor and remove any residual gas. Take the carburetor parts apart by disconnecting the float from the body and remove the rubber gasket. Spray the cleaner on the carburetor’s metal parts and avoid using it on rubber parts. Ensure that the jet is cleaned correctly. Reassemble the carburetor parts and mount it back on the engine.

● Fix 3 – Gas pressure washer: Check the Fuel cap and Air Filter

A clogged gas cap or air filter won’t allow the pressure washer to start correctly. A clogged gas tank cap makes it difficult for air to take the place of the used fuel in the gas tank. Clean the hole in the gas cap so that air can enter there.

Check and clean any dirt on the air filter. If you use a foam filter, you can wash it with some hot water. When really dry and clean, spay a little bit of oil on it. This helps to stick any small dirt particles on it. If the foam is damaged or can not be cleaned, replace it.

If you have a paper air filter, it can not be cleaned. And need to be replaced.

● Fix 4 – Gas pressure washer: Clean the Spark Plug

To clean the spark plug, disconnect the wires of the plug and remove it. Examine the plug for any damage. Also, inspect the electrode and the porcelain. If the electrodes are burned or if the porcelain is cracked, replace the spark plug. Otherwise, clean the spark plug and the area around it thoroughly with a metal brush. When clean, re-install it.

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