Setting up a pressure washer is less about muscle and more about matching the water supply, hose and fitting ratings, and nozzle choice to the pump, then confirming every control works before pressurizing. 

In commercial pressure cleaning, that same work is often treated as high-pressure water jetting, where a pressurized stream strips coatings and contamination, and the consequences of a mistake can be immediate. The Safe Work Australia guide for managing risks from high-pressure water jetting outlines typical system components and common hazards such as injection injuries, flying debris, noise, electrical risks, and chemical exposure.

This setup checklist turns those principles into a consistent pre-start routine that protects the pump and heater, stabilizes pressure and flow, and reduces avoidable failures like cavitation, overheating in bypass, seal damage, blown quick-connects, and incorrect tip selection.

Power Washer Setup Procedure 

Step 1: Pick a safe setup spot

Set the machine on flat, stable ground so it cannot roll, tip, or vibrate into obstacles while running. 

Keep it well away from doors, vents, and enclosed areas because engine and burner exhaust can build up fast and become dangerous. 

Aim the spray direction away from glass, vehicles, painted surfaces, and walkways so any accidental trigger pull does not cause damage or injury.

Step 2: Pre-start inspection

Before adding pressure or heat, do a quick check of the pump, hoses, and fittings so you catch small issues before they turn into failures. 

Look over hoses for cuts, bubbles, crushed sections, and loose crimps because weak spots can burst under pressure. 

Check fittings and O-rings because dry, cracked, or missing seals cause leaks, pressure loss, and air being pulled into the system. 

Inspect the nozzle because a worn or blocked tip changes flow, makes spray uneven, and can overload the pump. 

Confirm fluid levels like pump oil and engine oil because low oil can damage components of power washing quickly and lead to costly repairs.

Step 3: Water supply setup

Start with the water supply because the pump needs steady flow to avoid cavitation, which is air bubbles collapsing inside the pump and damaging it over time. 

Fit the inlet filter or strainer on the machine inlet to stop grit from entering the pump and wearing seals and valves. 

Connect the feed hose firmly so the inlet side stays airtight and does not pull air under suction. Turn the water on fully, then purge air by holding the trigger open until the stream is steady with no surging. 

If you hear rattling or pressure pulsing, treat it as a warning sign of air in the line, a restricted filter, or not enough flow, and fix the supply before starting work.

This step matters for both cold water and hot water machines because the burner can only heat safely when the pump has steady flow. 

If the water supply is weak, a hot water unit may overheat the coil or trip out, and a cold water unit may surge or lose pressure.

Step 4: Hose layout and gun setup

Lay hoses out in a simple, straight path so they do not kink, snag, or become trip hazards during operation. 

Keep the high-pressure hose as straight as practical because tight bends reduce flow and stress the hose. 

Avoid sharp corners because they can cut the outer jacket and weaken the hose over time, so reroute or use a guard when needed. 

Keep hoses away from hot mufflers, burner housings, and exhaust outlets because heat can soften or melt hose material. 

Connect in the correct order, machine outlet to high-pressure hose to gun or wand to nozzle, then lightly pull on quick-connects to confirm they are locked before pressurizing.

Step 5: Power source checks

For electric units, plug into a properly rated outlet and use an RCD if required so you reduce shock risk when working around water. 

Avoid long, light-duty extension leads because undersized cables cause voltage drop, which overheats motors and reduces performance. 

Keep plugs and connections off wet ground and away from spray so water cannot enter the electrical points. 

For petrol or diesel engine units, check engine oil first because low oil is one of the fastest ways to kill an engine. 

Confirm fuel is fresh and the fuel valve is open so the engine runs smoothly without stalling. 

Start with choke only as needed, then reduce choke once it runs cleanly so you do not foul the spark plug or run overly rich.

Step 6: Start-up sequence

Use a consistent start order to protect the pump and avoid dry running, which can ruin seals fast. Turn the water fully on first so the pump has a supply. 

Hold the trigger open so water is flowing through the pump and lines while you start the motor or engine. 

Once started, keep the trigger open for 10 to 20 seconds to purge remaining air and stabilize flow, then release and re-squeeze the trigger to confirm stable operation. 

What you want is a smooth sound, steady pressure, no leaks, and no surging, because those signs tell you the machine is properly primed and the supply is adequate.

Step 7: Test pressure and spray pattern

Always do a short test spray on a safe surface like plain concrete before moving to the real work area. 

Confirm the fan angle suits the job because too narrow can cause damage and too wide may not clean effectively. 

Check that pressure feels consistent, since pulsing usually points to air in the line, a blocked inlet filter, or nozzle problems. 

Watch closely for leaks at the gun swivel, hose ends, and quick-connects because leaks can worsen under full pressure and become a failure point. 

If pressure is weak, start with the simple checks: confirm nozzle size and wear, clean the inlet filter, make sure water is fully on, and look for air leaks on the inlet side.

Step 8: Hot water setup

Only switch on the burner after cold-water pressure is stable, because the burner relies on steady flow to heat safely and avoid overheating the coil. 

Use the correct fuel type recommended by the manufacturer because the wrong fuel can cause poor combustion, soot buildup, or ignition issues. 

Check fuel level and cleanliness since old or contaminated fuel can clog filters and nozzles and cause repeated shutdowns. 

If the unit has a burner fuel filter, confirm it is not overdue because restriction reduces fuel flow and can cause flame problems. 

For ignition, start the machine and confirm steady flow at the gun, set the thermostat to a conservative starting point, then turn the burner on and wait 30 to 60 seconds before judging heat output. 

During temperature checks, aim for a clear temperature rise and stable operation rather than maximum heat, and if you see steam, smell harsh fumes, or the unit trips out, turn the burner off and keep water flowing to cool the coil. 

The safest rule is to use the lowest temperature that achieves the result, because excessive heat can damage surfaces, seals, paint, and grout.

Step 9: Chemical injector setup

Use the chemical injector only when detergents are needed and the machine is set up for it, because incorrect chemical use can damage internal parts. 

Confirm the correct injector and pickup tube are installed so the system can draw chemicals properly. 

Some units only draw chemicals when using a low-pressure mode or specific nozzle, so choose the correct nozzle setting before expecting it to siphon. 

Prime the chemical line briefly, then flush with clean water after use so residue does not crystallize, corrode parts, or block the injector. 

Avoid running bleach or acids unless the system is designed for them, because harsh chemicals can destroy seals, pumps, and heating coils.

Step 10: End-of-run shutdown

Shut down in a way that protects the coil and makes the next start easier. 

On hot water units, switch the burner off first so the machine stops adding heat. 

Keep water flowing for 1 to 3 minutes to cool the coil and prevent heat soak damage inside the burner and coil area. 

Then stop the motor or engine, turn the water off, and squeeze the trigger to relieve trapped pressure so hoses and fittings are not left under stress. 

Disconnect, drain, and coil hoses neatly so water does not sit in lines and cause corrosion, freezing damage, or stale smells. 

If storing in cold areas, winterize as the manual recommends because frozen water expands and can crack pumps, hoses, and coils.

Quick checklist (printable)

Safety first

• Wear PPE: safety glasses, closed shoes, gloves, hearing protection
  
• Keep people and pets away from the spray zone
  
• Never point the gun at skin, even at “low pressure.”
  
• Confirm good ventilation for engine exhaust and burner exhaust (hot water units)
  

Pre-start inspection

• Read the rating plate or manual for max PSI, max LPM/GPM, and max inlet temperature
  
• Check pump oil level (if applicable) and look for milky oil (water contamination)
  
• Check engine oil and fuel (engine-driven units)
  
• Check burner fuel level (hot water units)
  
• Inspect hoses, gun, wand, fittings, O-rings, and quick-connects for damage
  
• Confirm the correct nozzle/tip is fitted and clean
  

Water supply setup

• Use a clean water source with enough flow for your machine
  
• Connect the garden/feed hose, fit the inlet filter/strainer, and tighten the connections.
  
• Turn water fully on
  
• Purge air: hold trigger open until water flows smoothly (no sputtering)
  

Hose layout and straight Sections

• Lay out hoses straight; avoid kinks and tight bends
  
• Keep hoses away from hot mufflers, burner coils, sharp edges, and traffic paths
  
• Connect the high-pressure hose to the machine outlet, then to the gun/wand.
  
• Check for drips and leaks before starting the motor/engine
  

Start up and pressure test the motor/engine

• Let it run 30 to 60 seconds to stabilize
  
• Test spray pattern and pressure on a safe surface
  
• Confirm the unloader is working (pressure drops when you release the trigger).
  

Hot water (burner) ignition and temperature check

• Confirm burner fuel type is correct and clean
  
• Set thermostat to a moderate starting temperature
  
• Switch burner on only after water flow is stable
  
• Verify heat rise at the outlet; watch for overheating or steam
  

Shutdown (end of job or pause)

• Turn burner off first and run cold water through for 1 to 3 minutes
  
• Stop motor/engine
  
• Turn water off
  
• Squeeze trigger to relieve pressure
  
• Coil hoses, drain water if transporting, and store safely
  

Common Power Washer Setup Mistakes to Avoid

• Starting the machine before turning on water
  
• Skipping the inlet filter and pulling grit into the pump
  
• Using a worn nozzle and wondering why pressure changes
  
• Turning the burner on before water flow is stable
  
• Running too hot for the surface (paint, timber, sealers, soft stone, asphalt)
  
• Letting hoses kink, rub on sharp edges, or sit against hot exhaust parts
  

Fast troubleshooting guide: problems and solutions

Problem: Pressure surging or pulsing

Solutions (do these in order):

• Purge air again: keep the trigger open until flow is steady (no sputter).
  
• Clean the inlet strainer/filter.
  
• Check the feed hose: remove kinks; use a larger diameter hose if needed.
  
• Tighten inlet connections: any loose fitting can pull air.
  

Problem: Weak pressure

Solutions (do these in order):

• Confirm the correct nozzle size and replace worn nozzles.
  
• Check for leaks at the fittings, the gun, the wand, and the swivel.
  
• Confirm the water supply flow is enough (tap fully open, no restrictions).
  
• If all the above checks out, inspect the unloader valve (service per manual).
  

Problem: No hot water

Solutions (do these in order):

• Check burner fuel level and confirm the correct fuel type.
  
• Replace or clean the burner fuel filter if restricted.
  
• Increase the thermostat temperature setting (if set too low).
  
• If still cold, follow the manual for ignition fault checks (spark, safety lockout, sensors).
  

Problem: Leaks at quick-connects

Solutions (do these in order):

• Replace missing or damaged O-rings (correct size and material).
  
• Clean dirt/grit from the coupling.
  
• Reseat the quick-connect until it clicks and locks fully.

FAQs

1) Do I start the burner before I start the washer?

No. Start with cold water flow first, confirm stable pressure, and then switch the burner on.

2) Why must I purge air from the system?

Air causes surging, pump noise, and cavitation, which can damage the pump over time.

3) What is the inlet strainer for?

It catches grit and debris before they enter the pump, protecting seals and valves.

4) Why does my pressure drop after a few minutes?

Common causes are a clogged inlet strainer, a kinked feed hose, or a worn nozzle tip.

5) Can I use any detergent through the injector?

Use only chemicals approved for your machine and task. Some chemicals damage seals and coils.

6) Why cool down a hot water unit after use?

Cooling water prevents heat soak in the coil and burner assembly, which protects parts and reduces faults.

7) How do I choose the right nozzle tip?

Match the tip to your PSI and flow rating and the surface you are cleaning. A wrong tip can reduce performance and overload the pump.

8) Is hotter water always better?

No. Use the lowest temperature that achieves the result to avoid surface damage and wasted fuel.

9) What should I do if the machine smells harsh or produces steam?

Turn the burner off immediately and keep water flowing to cool the coil. Then troubleshoot.

10) Can I leave the unit pressurized between jobs?

No. Always relieve pressure at shutdown to reduce stress on hoses, fittings, and seals.