Whatever issue your Costco pressure washer is experiencing, the tables below will be of great help. If you can clearly identify the symptom, find it in the left column and then perform the actions suggested in the right column. For troubleshooting each model, there’s a separate table.
| Problem | Cause | Solution |
|---|---|---|
| Engine Won’t Start | Make sure you’re using the correct starting procedure. Once the engine is running, you must push the choke back in or the engine will sputter and die | |
| It may be flooded. | Try cranking it with the choke in. If you smell gas, let the engine sit idle for 10 minutes before trying again | |
| The air filter may be dirty. | Open the air filter compartment, and clean the filter with compressed air or soap and water, depending on the recommendation in the owner’s manual | |
| The spark plug may not be firing. | Unhook the boot; remove the plug and inspect the terminals. If they are clogged with black deposits, clean them with sandpaper or a file. If the they are corroded, replace the plug | |
| The fuel may be bad. | If the power washer has been in storage with gas in the tank and you forgot to add stabilizer, drain the old fuel and replace it with fresh fuel. Old fuel can collect moisture that foils the carburetor | |
| The carburetor or fuel lines may need cleaning. | You may need to disassemble the carburetor for a thorough cleaning, but first try removing the air filter and spraying starting fluid in through the air intake port. If the engine turns over, it may burn off some of the sludge that’s causing the problems | |
| Engine Stalls | If the engine doesn’t run to speed or it stalls when you try to spray, the problem is often blocked air passages. Clean or replace the air filters. It’s also possible that the carburetor needs adjustment — take the unit in for servicing if you suspect this | |
| Low Nozzle Pressure | The nozzle may be blocked. | Shut down the engine; remove the nozzle and clean it by back-flushing it with water |
| If you have an adjustable nozzle with multiple settings | , make sure you’ve selected the proper setting. A setting for mixing soap for cleaning has a wide aperture that won’t provide much pressure | |
| It’s also possible that a filter in the hose or at the spigot needs to be cleaned | ||
| Falling Pressure | It could mean that the water source isn’t supplying enough water. | Disconnect the hose and measure the gallons per minute from the spigot, using a bucket. Compare this number to the requirements for the power washer you’re using |
| There may be a kink in the garden hose supplying the power washer | ||
| One of the supply fitting or hoses may be leaking |
| Problem | Solution |
|---|---|
| My Pressure Washer Is Running Very Rough | Do you have a hot water and cold-water outdoor faucet? The #1 reason why a pressure washer begins to run rougher than usual is that the inlet water is too hot. Make sure to use cold water to get the best results. Even if you don’t have a hot water faucet, water that has been trapped in a hose with sunshine coming down on it can warm up enough to cause this problem. |
| Not having enough air entering the inlet plumbing or having a stuck inlet can also cause the same problem. It comes from the other side of the equation – after all, you need to have air and water to create pressure! Make sure these are all working properly and be sure to check your discharge valves as you investigate. You’ll also want to check on the air filter of your pressure washer and replace it if necessary. | |
| If everything looks fine and you aren’t using hot water, then there’s a good chance that you’ve got mechanical damage within your crankcase. That’s not a problem you can generally repair at home | |
| My Pressure Washer Is Leaking | One of the most common issues in pressure washer repair is a worn out seal. There are numerous seals that are distributed throughout the design of the pressure washer and any one of them may fail spontaneously to create a leak. It isn’t just water that can leak either. Oil leaks are also very common. Make sure that you check your seals at least twice per year and quickly replace ones that appear to be worn out. |
| Sometimes leaks can be caused by worn out packing or plungers that are broken or scored. This tends to happen after at least a season of use, but heavy users of their pressure washer may see this problem creep up on them even sooner. You’ll need to replace the damaged seals as you find them. | |
| The seals of the pressure washer are also bound by the laws of physics. They expand and contract based on how hot or cold the weather happens to be. High humidity weather can actually cause a pressure washer to begin leaking, especially when it comes to keeping the oil and water separate from each other | |
| My Pressure Washer Is Pulsating | This issue is almost always caused because of a dirty inlet or discharge valve. Make sure that you clean these out thoroughly after 5 or 6 uses, especially if you are pressure washing wooden materials. Even hardwood will splinter at times when high-pressure water streams are encountered. These small splinters then clog up the system. |
| You may also have a stuck plunger for a wide variety of reasons. If your inlet and discharge valves are clean, then the plunger is the likely the cause of the pulsating, especially if you have low pressure while this is happening | |
| My Pressure Washer Just Shut Off | The modern pressure washer is designed to make sure that you don’t damage the engine or any of the mechanical components if you manage to forget some basic maintenance. There are two primary reasons why a pressure washer will shut off: it has run out of fuel or it has run out of oil. |
| A good practice to get into the habit of doing is to check the oil levels of your pressure washer every time you plan to turn it on. Do this even if you have just filled the oil reserve up. This will help you discover any leaks that might have developed over the life of the equipment or flaws in its manufacturing process if you’ve just purchased it. | |
| The one catch to this process is that once you place fuel and oil into a pressure washer to check if it will work, you can no longer ship it back due to current laws. You will need to have it serviced locally. | |
| Some pressure washers will also shut off if their thermostat reaches a certain threshold. You will see this happen more often when you use the equipment in a confined area where there isn’t enough air to cool the engine down. This may also happen on hot and humid days. You will need to allow the pressure washer to cool down for at least 30 minutes before restarting the engine | |
| My Pressure Washer Won’t Start | If you know that you’ve got fuel in your pressure washer and that you’ve got oil in it too, then the next thing to check is the primer pump. You will need to pump the fuel primer for the engine 6-7 times on the first start-up of the season and 2-3 times for every other start-up. If you don’t get a good start from the first 3 or 4 pulls, then you’ll flood the engine and need to let it sit for a few minutes. Run the choke on full, pull a couple of times, and then gradually pull the choke off as you get the engine going. |
| Some pressure washers today are electric and won’t start either. This is typically because the power supply attached to the equipment isn’t adequate. Some older homes may only be wired for 60 amps and if your refrigerator and dryer is already running at the same time, there just might not be enough juice to fire that equipment up. Take some of the load off the electrical system and you should get a successful start. | |
| You may also need to check your electrical panel and replace older fuses that may not be capable of supporting your new equipment |
| Problem | Cause | Solution |
|---|---|---|
| Pressure washer will not start. | No fuel. | Add fuel. |
| Faulty spark plug. | Replace spark plug. | |
| Pressure washer will not start; | Low oil level. | Fill crankcase to the proper level. Place pressure washer on a flat, level surface. |
| Pressure washer starts but runs roughly. | Choke in the wrong position. | Adjust choke. |
| Spark plug wire loose. | Attach wire to spark plug. | |
| Pressure washer gallops. | Engine governor defective. | Contact the help line. |
| Unit does not reach high pressure. | Water supply is restricted. | Check hoses for leaks, blockage, kinks. |
| Garden hose is too small. | Replace with 5/8 in. garden hose or larger. | |
| Garden hose inlet filter is clogged. | Remove garden hose, clean filter and rinse out. | |
| Not enough inlet water. | Turn garden hose water on full force. | |
| Spray pressure varies from high to low. | Poor inlet water supply. | Turn garden hose water on full force. Check hose for leaks, blockage, or kinks. |
| Garden hose inlet filter is clogged. | Remove garden hose, clean filter and rinse out. | |
| Spray nozzle is obstructed. | Remove particles with small wire rod | |
| Pump is sucking air. | Check all hoses and fittings, make sure they are securely tightened down and fastened. Turn off engine and purge pump by squeezing trigger gun until a steady stream of water flows. | |
| Low pressure detergent wash is not functioning properly. | Detergent is too thick. | Dilute detergent |
| Spray wand has high pressure quick connect nozzle installed. | Detergent only works with low pressure quick connect nozzle (black). | |
| Detergent hose is not connected to the pump housing. | Check connection. | |
| Spray nozzle is obstructed. | Clean nozzle and remove debris. | |
| Filter on detergent hose is clogged. | Clean with warm water or replace. | |
| Chemical Injector valve (inside pump) partially blocked or stuck. | Quickly pull and release the gun trigger 4-5 time to clear the chemical injector valve. | |
| Detergent tube not connected to the brass fitting on the pump outlet. | Install detergent tube to detergent injector inlet near pump outlet. | |
| Garden hose connection leaks. | Loose fittings. | Tighten. |
| Missing/worn-out rubber washer. | Replace rubber washer. | |
| Spray wand leaks | Spray wand not properly attached. | Tighten all connections. |
| Can’t pull recoil | Pump will build pressure with each pull. | Pull gun trigger after 2 pulls of recoil, to release pump pressure. |