Pressure Washer Do’s and Don’ts –
Proper Care of Your Machine for Long Lasting
17 February, 2020 by
Pressure Washer Do’s and Don’ts –
Dirt Killer Kranzle USA Atlantic Pressure Washers, Michael Zittel DK

The two most important issues concerning breakdowns are cavitation and overheating due to excessive time in by-pass.  Cavitation is caused when there is not enough water supplied to the pump.  For example: if your machine is rated to pump 3.0 gallons per minute (GPM) you must have a supply of 3.0 GPM or more at all times.  Even at 2.9 GPM, only a tenth of a gallon lower than rated, will over time cause sufficient damage to all parts of the pump.  A good way to check on this is to fill a five gallon bucket with the supply hose and time how long it takes to fill.  The supply to your machine must be higher GPM than the rating on the pump.  Cavitation can be felt at the gun jet as a surging of pressure.

By-pass is the condition of the machine when the gun jet trigger is not depressed.  Our recommendation is not to let go of the gun jet for longer than 30 to 45 seconds.  It is easy for the person a pressure washer to be distracted by something.  This distraction can be a phone call, moving to another location, or many other things that might happen on a job site.  Manufacturers’ recommendations are for no more than two minutes in by-pass.  Excessive by-pass causes the pump to heat up within minutes to 140 degrees Fahrenheit and higher.  Depressing the gun jet while the pump is hot causes thermal shock by sending fresh, cold water over hot pistons.  To avoid this, the machine should be shut down if leaving the unit for more than 30 or 45 seconds…everytime.

Signs of significant pump failure:

Milky oil – water seals or pistons have damage – service immediately.

Silver or metallic oil – pump transmission failure – service immediately

Excessive oil leaking or spraying from pump – water is pressurizing pump due to worn seals and or cracked pistons – service immediately

Engine stalls or “bogs down” while under pressure – pump failure, or by-pass has malfunctioned – service immediately.


Always verify the GPM output of the supply hose is adequate for machine.  Check supply filter.

Always check engine and pump for proper level and color of oil before every use.

Always shut unit down when letting go of the gun jet more than 30 – 45 seconds.

Always change oils regularly every 250-300 hours of use (pump and engine).

Always shut down burner first, run for 1-2 minutes or until cold, and then shut the engine down. (Applicable only to hot water units).  Always run at full throttle while burner is on.

Always make sure supply valve (house or jobsite) is open all the way.

Always get valves adjusted every 300 hours (Honda engines only) or warranty is void.

Always run antifreeze through unit during the winter months, and if more than two months will elapse between uses.  If using during freezing temperatures, run antifreeze immediately after each use.


Never walk away from a unit while running in by-pass for more than 45 seconds.

Never kink supply or high pressure hose, or run over with a car or forklift.

Never run a unit with water leaks anywhere on the machine (gun jet, hose, fittings, etc.).

Never continue to run a unit with milky or metallic oil.  Running a unit until it quits just to finish a job is costly.

Never throttle down an engine while the burner is running, or shut down a unit while the burner is on.

Never tip a machine over or run it at an angle: the oil will not properly lubricate the internal parts.

Never allow the unit to freeze.  Just blowing out water will still leave enough water in the unit to cause major damage when the unit freezes.

Pressure Washer Do’s and Don’ts –
Dirt Killer Kranzle USA Atlantic Pressure Washers, Michael Zittel DK 17 February, 2020
Share this post