Pressure Washing Trouble Shooting Guide

[Ryan Cash]

What do you do if you are getting low water flow/no pressure at the end of your gun?
What could cause the water to sputter out of the end of your spray tip?
Why is my surface cleaner not spinning any more?
Why is my pump cavitating?

All of these are pretty common questions that could be the result of one of many problems.

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First, Let's define a few terms:

Cavitation: the formation & accumulation of bubbles in the pressure pump. When these bubbles are put under pressure they collapse and create small implosions inside the water effecting the surrounding parts. This can lead to a loud, rough sound coming from the pump and a loss of pressure and water flow.

Check Valve: self-actuating, one-way or non-return valve. This automatic safety device allows fluids to flow freely in one direction. However, if the fluid flow is reversed, the valve will automatically close, thus protecting the connected piping and pump.

Unloader: A pressure washer unloader valve diverts the water flow through the bypass when the trigger on the gun is depressed. The Unloader valve is designed to respond to an increase in pressure or a change in water flow. The unloader valve can also be used for adjusting the pressure of your machine.

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The key to solving these problems is to start at the nozzle and work your way back to the pump. Be systematic and tackle one system at a time.


Here is a basic walkthrough of troubleshooting the Rooftec XCS500 System that can be applied to most systems on the market. Start with #1, and continue along until problem is resolved.



BEFORE BEGINNING, VERIFY ALL WATER, BLEACH, AND SURFACTANT TANKS ARE FILLED. A common mistake that is sometimes overlooked is having empty tanks. This introduces air into the system and can lead to any of these problems.



Steps 1-4 will allow you to determine if there is a problem with the internal plumbing of your machine/pressure pump or simply an issue with the accessories (hose,spray gun/etc.).

1. Check Spray Nozzles
   1. Remove Nozzles from Wand/surface cleaner
   2. Inspect/Replace if damaged or Clogged
2. Check Spray gun/Spinner
   1. Check all o-rings and quick connects (any leaks?)
   2. Grease any swivels if needed
   3. Verify Nozzles are properly aligned with spray bar on spinner
   4. Replace damaged/broken Spray bars/swivels
3. Check Pressure Hose
   1. Pinhole leaks or larger breaks in hose? – Replace Hose
   2. Bad/Missing O-rings – Replace with new Viton O-rings
   3. Is the hose kinked or pinched? – Stretch out hose to relieve kink, replace hose if damaged
   4. Clogged with heavy debris? – Verify water can freely flow through hose
   5. Bubbled hose? – Hose has likely been run over or internal braiding has been damaged, Replace
4. Check Hose Reel
   1. Disconnect Pressure Hose from Hose Reel
   2. Inspect fittings and quick connects for clogs/leaks
   3. Take apart swivel and check for rust/failure – Replace or grease if needed
   4. Inspect hose from pump to hose reel to verify proper function.

If you are continuing to have issues with your machine after steps 1-4, the next most likely culprit is the internal plumbing on your equipment or the pump itself.


Before continuing, if possible, remove any bleach from tank and replace with water. (This will prevent you from spraying bleach all over as you are trouble shooting.) Follow these steps to continue troubleshooting:

1. Check all Hose Connections for Air Leaks
   1. Leaks will usually show up as bubbles in your clear braided supply line. These could be associated with loose clamps, cracked fittings, or even rubbed spots in the hose feeding the mixing manifold from the supply tanks.
      • Tighten all hose clamps
      • Use a small spray bottle filled with water and soap to spray each hose connection
      • Watch for bubbling as the machine runs
      • If bubbles appear, this is a connection that needs to be tightened
      • Inspect all plumbing for abrasions/holes
   2. Isolate each individual line but shutting off each valve on your mix manifold and turning on one at a time. Draw fluid through just one system at a time to see if the problem goes away.
      • By isolating each supply (water, bleach and surfactant) you can usually isolate the culprit.
      • You are not checking for volume at this point, the unit doesn’t need to be run at full speed, you’re just checking for leaks.
      • The surfactant supply lines are of a smaller size, so you don’t need a lot of volume to verify it is okay.
   3. With one system on and all others off, look for any bubbles or foamy looking supply in the clear braided line.
      • If nothing is noted, how does the pump sound?
      • Does it sound smooth (normal) or is there chattering or knocking coming from the pump?
        • Testing should be done with an output line attached and flowing fluid. Test each system separately, turning one system off before testing the next.
      • If you leave the unit running while turning one off and the next on, you will hear the pump cavitating (chattering) between switching.
   4. If you get chattering but don’t see any bubbles in the line, it could still be a leak at the pump head itself
2. Inspect the Pressure pump and Check Valves
   1. Check valves also act like supply leaks with no signs of bubbles
      
      
   2. Suction check valves being stuck open won’t allow the pump to properly pull fluid into the pump, causing it to starve (reduced flow) but without the chatter from the pump
      
      
   3. High pressure check valves being stuck usually just presents as the loss of pressure.
      • Not able to go above a certain pressure, maybe 1,000 psi instead of 2,500 psi.
   4. Loosen the check valves on pump, inspect for wear, rust, or debris causing the check valves to not properly function
      
      
   5. Remove debris and close up the pump
3. Inspect the Unloader
   1. The last component in the system that could be causing problems is the unloader.
      
      
   2. If the unloader is the issue, you won’t be able to reach pressure - just as if there was an issue with the high-pressure check valves
      
      
   3. You also may have reduced flow just like the suction check valves or possible leaks.
      
      
   4. The unloader can stick open causing fluid to recirculate around and back into the inlet of the pump causing reduced flow and inability to build pressure.
      
      
   5. The unloader may make noise, like the check valves in the pump chattering.
      
      
   6. Under normal conditions, the unloader handle will move in and out as the tool is triggered, in for flow, out for no flow through the tool.
      • If the handle doesn’t move then the stem and O-rings may need lubrication
      • If it chatters continuously the bypass valve (in the unloader) may be stuck, needing lubrication or damaged and need replacement.
   7. Take apart the unloader, CAREFULLY, as to not lose any small parts
      
      
   8. Inspect, Clean, Lubricate and replace

These steps are designed to help you trouble shoot some of the most common problems you’ll encounter with your equipment. While they may not answer every question you may have, they should help you get started. The most important thing to remember is to check/work on one system at a time. Isolate the problem and work on it!