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How to keep your pressure washer coil in good condition


Your new Hotsy Water Blast hot water pressure washer is designed for top performance in the harshest conditions. However, it still requires some maintenance to run efficiently and smoothly. An essential part of hot water pressure washer maintenance is water heater coil cleaning. Here are some tips for maintaining your pressure washer heating coil.

Coil scaling

If you work in Western Canada, chances are you’re using hard water in your pressure washer. Hard water leaves behind lime, calcium and magnesium deposits on the inside of the heating coil. Over time, the buildup makes it more difficult for water to pass through the coils and there is less heat transfer making the coil less efficient. Symptoms of limescale buildup include:

  • Decrease in water temperature
  • Reduced water pressure
  • It takes longer to get up to operating water temperature
  • You notice more load on the motor and the pump
  • There’s less water volume from the nozzle
  • The nozzle is getting clogged more often
  • Relief valves are blowing due to excess pressure

Scaling is more common in hot than cold water pressure washers.

Preventing limescale buildup

Pressure washer owners must ensure they operate their machines correctly and follow the manufacturer’s instructions. Failing to do so can lead to premature scale buildup and poor performance. Here are some tips on preventing limescale buildup.

  • An important thing you can do to prevent limescale buildup in your heating coil is to allow the unit to cool down after each use. Shut down the motor only after the boiler has cooled. When finished pressure washing, turn the boiler off and squeeze the trigger for about a minute or until the wand feels cool.
  • Installing a water softener system removes minerals from the water, reducing scale buildup in your pressure washer heating coil. Hotsy will provide and install the right water softener system for your washing needs. This will ensure the Hotsy coil will remain running efficiently, reduce coil maintenance, and avoid expensive coil replacements.
  • Regular preventative maintenance with a trained professional ensures your heating coils are clean and your machine performs at peak efficiency. Sign up for a scheduled maintenance plan, and your pressure washer dealer will keep track of your service calls and tell you when it’s due for a tune-up.

How to descale your heating coil

If you can’t get to an authorized Hotsy dealer, you can try descaling your heating coils yourself. Follow these steps:

  • Connect about two metres of hose to the suction side of an auxiliary pump. Connect a discharge hose between the auxiliary pump output port and the drain tee at the bottom of the coil.
  • In a 20-litre container, mix eight litres of water with four litres of pressure washer coil cleaner.
  • Operate the auxiliary pump and circulate the acid mixture through the coil system for 30 minutes or until the discharge solution stops foaming.
  • Remove the auxiliary pump assembly and reconnect the plumbing.
  • Operate the machine and pump clear water through the unit for five minutes to neutralize any remaining acid while flushing out all sludge deposits. Replace the gun nozzle.

Remember to flush the hose and rinse the acid solution from all equipment after cleaning.

Soot buildup

Another issue with hot water models is soot buildup on the pressure washer burner coil. When the unit isn’t burning fuel correctly, smoke produces a layer of black soot on the outside of the coils. You may notice the water temperature isn’t as hot as it should be or that it takes a long time for the water to reach operating temperature.

Fuel-burning issues are also a safety concern due to the release of carbon monoxide. If you see excessive smoke coming from the oil burner, it’s time for a tune-up.

Preventing soot buildup

You can prevent soot from forming on your coils by following these tips:

  • Ensure proper voltage supply by running gasoline engine at full throttle. Low voltage will reduce the RPM of the burner motor and not allow for proper airflow for combustion. Adjust the RPMs, as low voltage will affect the performance of diesel burners.
  • Replace old dirty fuel with fresh diesel, or add soot remover to the tank.
  • Replace the electrodes. Chipped, damaged, and or mis-aligned electrodes result in a poor fuel burn.
  • Adjust the air-to-fuel mixture.
  • Replace the burner fuel filter every three to six months based on usage.
  • Get your pressure washer professionally cleaned and maintained regularly by a qualified technician.

Pressure washer maintenance and repairs in Western Canada and North Dakota

At Hotsy Water Blast, our expert technicians provide pressure washer heater coil repair and maintenance services for our commercial and industrial clients. Contact us today to book an appointment at one of our nine locations in British Columbia, Alberta, Saskatchewan and North Dakota.