Quick Answer

If your pressure washer has low or fluctuating water pressure, the most common causes are air trapped in the system, leaks in the hose or attachments, or blockages in the spray gun or nozzle. Following the checks below will often restore normal pressure.

Tip: If you've recently connected your pressure washer or haven't used it for a while, perform a line purge to remove trapped air before using the machine.

Before You Begin

For your safety:

• Switch the pressure washer OFF.
• Disconnect it from the mains power supply (or remove the battery on cordless models).
• Turn off the water supply before disconnecting any hoses.
• Never inspect hoses or fittings while the system is pressurised.

1. Check for Leaks

Inspect the entire pressure washer system for water leaks.

Check:

• The garden hose connection.
• The high-pressure hose.
• The spray gun.
• The lance and nozzle.
• Any quick-connect fittings.

If water is leaking from any connection, tighten it securely or replace any damaged components.

Important: Even a small leak can reduce water pressure significantly.

2. Check for Blockages

Inspect the spray gun, lance and nozzle for debris or blockages.

Blocked nozzles can restrict water flow and reduce cleaning performance.

If necessary:

• Remove the nozzle.
• Clean away any dirt or debris.
• Refit the nozzle securely.

3. Purge the System (Remove Airlocks)

Air trapped inside the pressure washer can reduce or interrupt water flow.

Follow the steps below to purge the system.

Step 1

Switch the pressure washer OFF and disconnect it from the mains power supply.

Step 2

Turn OFF the water supply.

Step 3

Disconnect the spray gun or lance from the high-pressure hose.

Step 4

Turn the water supply ON.

Allow water to flow freely through the machine and out of the hose for 10–15 seconds.

This helps remove trapped air and flush out any debris.

Step 5

Turn the water supply OFF.

Reconnect the spray gun or lance.

Step 6

Reconnect the pressure washer to the mains power supply.

Turn the water supply ON again.

Point the spray gun in a safe direction and squeeze the trigger to allow water to flow through the system.

Step 7

Switch the pressure washer ON.

The machine should now build pressure normally.

Cordless Pressure Washers

If you are using a cordless pressure washer:

After switching the machine on, allow 10–15 seconds for the pump to draw water from the bucket or external water source.

This is normal and does not indicate a fault.

My Pressure Washer Still Has Low Pressure

If the pressure has not improved:

• Check the water supply is fully turned on.
• Inspect all hoses for leaks or damage.
• Ensure the nozzle is clean.
• Repeat the line purge procedure.
• Confirm the inlet filter is clean and free from debris.

If the problem persists, please contact our Customer Support team for further assistance.

Frequently Asked Questions

Why has my pressure washer suddenly lost pressure?

The most common causes are trapped air, a blocked nozzle, leaking hose connections or an inadequate water supply.

What is a line purge?

A line purge removes trapped air and debris from the pressure washer by allowing water to flow through the machine before it is switched on.

Why is my cordless pressure washer slow to build pressure?

Cordless pressure washers require a few seconds to draw water from the external water source. Allow 10–15 seconds before expecting full pressure.

Can a leaking hose reduce pressure?

Yes. Any leak in the high-pressure system will reduce the pressure delivered to the spray gun.

What should I do if the pressure still doesn't return?

Check for leaks, clean the nozzle, inspect the inlet filter and repeat the line purge. If the issue continues, contact our Customer Support team.