How to Descale a Coil in a Pressure Washer

Pressure washers are effective at cleaning dirt, grease, oil and other substances off of surfaces such as concrete, brick or wood.
Pressure washers rely on hot water for their cleaning efficacy.Pressure washers rely on hot water for their cleaning efficacy.
However, the pressure washer itself needs cleaning occasionally if you want to keep it in peak condition. Water often contains minerals that accumulate and harden over time and this scale negatively affects a pressure washer's performance. If the washer's heating coil gets scaly build up, it can't heat the water as efficiently and the washer's performance suffers. Removing the scale from the coil helps restore functionality.

Step 1

Fill the pressure washer's reservoir with an acid-based coil cleaner. Make sure the cleaner is designed for pressure washers so it can go through the pump without causing damage. Wear protective gloves and safety glasses because the cleaner is corrosive. Follow any dilution instructions on the packaging.

Step 2

Turn on the pressure washer and spray out the cleaning solution on a driveway, parking lot or other location where it won't damage the surface it touches. Stay away from trees and plant life. The cleaner breaks down the scale as it goes through the system. You can also spray the cleaner into a bucket.

Step 3

Rinse the ground with a regular garden hose once you're finished to dilute the cleaner. If the cleaner went into a bucket, mix it with at least half water before dumping it. Follow any disposal instructions on the packaging.

Things You Will Need

  • Acid-based coil cleaner
  • Protective gloves
  • Safety glasses
  • Bucket


  • Do not use an acid-based coil cleaner on aluminum or tin.

About the Author

Michael Davidson started writing screenplays in 2003 and has had a screenplay professionally produced. He has also studied martial arts since 1990 and has worked as a licensed security specialist. Davidson has written articles for various websites. He is a graduate of Michigan State University and holds a Bachelor of Arts in advertising.