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Step by step guide

Easy: replace switch box

Servicing our pressure washers are quite straight forward and could be done by most people by following the step-by-step instructions in this manual. Please go trough the whole manual before starting work on your pressure washer to make sure you understand the procedure and that you have the necessary tools to complete the task.

Always unplug the pressure washer from both the mains power and the water outlet before starting the service. Even though power and water is disconnected there may be pressurized water in the hose. Discharge this pressure by pulling the trigger on the gun. Make sure your work area is clean and appropriate for the work you are about to do. There will usually be a small amount of water inside the pump and hose. If you are doing a 10-year service, then be prepared to collect the used oil from the oil chamber. Please dispose of the oil in accordance with local law and regulations. ISO 46 hydraulic oil can be substituted with similar non detergent oil of the same viscosity.

00. Parts and tools

An overview of what is needed to do this service.

01. Remove the water filter

Unscrew the water filter and remove it.

02. Remove screws

Unscrew the 5 T25 screws from the hose reel assembly.

03. Remove the hose reel assembly

Get a firm grip on the hose reel assembly. Lift it upwards and outwards. Pull the assembly out of the cabinet. Make sure to release the power cable strain reliever from its slot.

04. Remove inlet pipe and on/off knob

Use a small flat head screwdriver to pry loose the U-pin from the pump head.

Remove the inlet pipe and the on/off knob

05. Remove the motor cowling

Remove the motor cowling.

Unscrew the 2 T25 screws securing the switch box to the pump.

06. Disconnect the motor power cables

Disconnect the motor power cables by pressing down the locking tab and gently pull them apart.

Remove the switch box by pulling it in the direction indicated. It is press fitted onto the start/stop valve on the pump.

07. Open the old switch box

If your switch box came without a cable you need to open the old switch box to extract the cable. If your switch box came with a cable you can move on to step 11.

Unscrew the 5 Phillips head screws holding the lid.

08. Extract the power cable

Remove the lid from the switch box.

Release the mains power cable from the main switch. To release the cable, you need to press down the small locking tap on the spade connector.

09. Attach the power cable to the new switch box

Open the lid on your new switch box and connect the mains power cable to the main switch. It does not matter which way you connect it to the main switch as this is alternating current.

Make sure that the sliding and rotating pin is correctly situated before closing the lid.

10. Close the new switch box

Fasten the lid using 5 Phillips head screws.

11. Attach the new switch box

Attach the new switch box to the pump. You need to put a decent amount of pressure to get the box firmly seated on the start/stop valve. It should pop into place.

12. Connect the motor power cables

Take the two power cables and pull them trough the plastic frame. Connect the female spade connector to the male spade connector. Give the cables a light tug to check that the connection is secured. The order of the connection is irrelevant since the motor runs on AC power.

13. Reattach the motor cowling

Fit the motor cowling over the motor.

Secure the switch box to the motor/pump using 2 T25 screws.

14. Reattach the water inlet pipe

Fit the water inlet pipe to the pump head and secure it using a U-pin.

Fit the on/off knob to the switch box.

15. Put the hose reel assembly back in to the main cabinet

Fit the power cable strain reliever in its slot.

Get a firm grip on the hose reel assembly. Lift the whole assembly and slide it into the cabinet. Some wiggling may be needed for the assembly to be properly seated.

16. Align the hose reel assembly

To check that the motor/hose reel assembly is properly seated, turn the on/off knob to see that it can operate freely. Also check that the water inlet is centered in its opening in the back cabinet.

17. Secure the motor/hose reel assembly

Once you are sure that the motor/hose reel assembly is properly aligned, you can secure the assembly using 5 T25 screws.

18. Reattach water filter

Check that the filter cassette is clean, then refit the water filter.

19. First start after service

Congratulations with finishing the service of your AVA product.

It is now time to do the first start after service.


  1. Start by connecting the pressure gun to the hose.
  2. Connect water.
  3. Make sure no water is leaking from the inside or anywhere else on the pressure washer.
  4. Pull the trigger and let the water flow until there is no more air coming out.
  5. Connect the power cord.
  6. Turn on the pressure washer.
  7. Pull the trigger and let water run for a minute before connecting a nozzle.
  8. Connect the nozzle. Use the pressure washer and make sure it is operating as normal.

20. Troubleshooting

Water is leaking from the inside

•Disconnect the power and open the pressure washer to locate the leak. Take necessary action to remedy any leaks.

Motor runs and won't stop when you release the trigger

•This is most likely due to an improper seating of the switch box on the start/stop valve. Open the machine and check that the switch box is correctly seated.•

The pressure washer won't turn on

•Check that the power cable is connected.•Check that the circuit breaker has not been tripped.•Check that the fuse in the power plug is intact (UK models only).•Open the machine and check that all the internal cabling is connected.•

Poor performance/pressure

•Improper assembly or dirt/debris in the pump. Check that the pump and especially the main valve for foreign objects/debris. Make sure that the spring in the main valve is correctly seated and working as intended.