Why Does My Electric Pressure Washer Keep Cutting Out?

There are a few reasons why an electric pressure washer will cut out, and nothing is more annoying. You’re all set to get some serious cleaning action going on, got everything you need, from detergent to boots and goggles, and the pressure washer cuts out.

Some faults are very common and easy to fix, while others can be serious and need expert help. Let’s get on to identifying the faults and see if we can’t get you up and running as soon as possible.

Reasons Why Your Electric Pressure Washer Could Be Cutting Out

Let’s go through the most common faults first, they are:

Problems With Your Power Supply

The first and most obvious is a faulty power connection. Check the plug, during use it’s easy to get carried away and over-extend the cable. This can slightly remove the plug from the power socket just enough to cut the power.

Another common reason is an extension cable, most manufacturers recommend only using an extension cable with a constant 13 amp rating and not more than 10 metres (30 ft) in length. Check the plug connections in the extension cable and be sure the cable is fully unwound.

Not Following The Correct Start-Up Procedure

The way pressure washers are designed, they can sense when water is flowing and then when the trigger is pulled the flow is boosted by the water pump. But, if there’s an air block in the system the machine will cut out. To prevent or remove an air block in the system always follow this step by step start-up procedure.

1. Remove the plug
   Turn off the power and remove the plug from the electric supply.
2. Remove the high-pressure hose
   Disconnect the high-pressure (black) hose from the outlet valve on the pressure washer pump.
3. Connect the garden hose
   Make sure the garden hose is connected to the inlet valve on the pump of the pressure washer and connect the other end of the garden hose to the outdoor tap.
4. Turn on the water supply
   Make sure the outdoor tap is fully on to ensure the water flow is full-powered.
5. Allow the water to run
   Without touching anything else, allow the water to flow through the pressure washer for at least 5 minutes.
6. Reconnect the high-pressure hose
   Ensure the black hose is fitted correctly to the outlet valve on the water pump on the pressure washer.
7. Press the trigger
   Pull the trigger on the spray gun, this will draw water from the garden hose through the high-pressure hose and the spray gun and force any air from the system.
8. Reconnect the plug
   Connect the plug to the power supply and turn on the power.
9. Turn on the pressure washer
   Using the dial on the pressure washer, set to “ON” to power up the pressure washer.
10. Start pressure cleaning
    Your pressure washer should now be running freely. 

If you’re still experiencing intermittent stop and start problems with your pressure washer there are a few more things you can do.

Check For Water Leaks In The Garden Hose

Check all the garden hose connections because if the pump doesn’t get enough water, this can cause the motor to cycle. Cycling is what electric pressure washer motors do when they sense too much pressure build-up in the water pump. As you pull the trigger, releasing the water pressure, the motor restarts to build the pressure again.

Garden Hose Blockage Stopping Water Flow

If there is a kink in the garden hose, this could be starving the pressure washer of water, this will cause the engine to cycle.

Check Pressure Hose Connections

If the pressure hose (black hose) is missing the washers at the connection points with the wand and the pump, this can also cause the motor to cycle on and off.

Hose Diameter Too Small

Try changing the garden hose to one with a larger diameter pipe. This will allow a stronger flow of water to the pressure washer.

Faulty Unloader Valve

The unloader valve or pressure regulator as it is also called is used to regulate the water pressure in the pressure washer. If the unloader valve is not working properly, it can either lose water pressure or allow too much water pressure build-up. Check for leaky washers or seals, and that the spring is working correctly.

If this isn’t the problem, try adjusting the unloader screw. The problem could also be the unloader valve needs recalibrating. Check the instruction manual for the correct calibration and adjust accordingly.

Water Pump Malfunctions

If the water pump is leaking any fluid, either oil or water, check all seals and bolts are tight. If after tightening the bolts, there are still leaks, contact the manufacturer if the pressure washer is still under warranty. Otherwise, contact a specialised pressure washer repairer.

While on the subject of water pumps, there are 3 types of pumps used on electric pressure washers. They all have different lifespans and prices which will obviously affect the price and longevity of your pressure washer.

Pump Types

Pump type	Average lifespan
Wobble plate pump	400 hours
Swashplate pump (Axial cam)	800 hours
Triplex plunger pump	8,000 hours

Choose the pressure washer with the pump type that best suits your requirements and your budget.

Clogged Water Filters Starving Pump Of Water

On some pressure washers, there is a screen on the pump that shows the water inlet filter, check to see if this is clogged and clean as necessary.

Motor Overheating

If you’re using your electric pressure washer on a hot, sunny day, the water in the garden hose can heat up and cause the water pump to have to work harder which in turn can make the motor overheat. This will cut your machine out eventually, but, if you smell burning or see smoke while operating your pressure washer turn it off immediately and disconnect the power supply.

If your pressure washer is still under guarantee contact the manufacturer, if not consider buying a new machine, as it often costs more to repair an old machine than it does to replace it.

Frequently Asked Questions