Acid Cleaning Of Water Coil - Water Source Heat Pumps

Date: 10/3/2017

Models: All Water Source Heat Pumps


  • Use extreme caution when handling muriatic acid
  • Contact with muriatic acid can result in serious injury
  • Be sure to wear eye protection and protective gloves
  • Acid cleaning should ONLY be performed by a trained technician

Acid Cleaning Procedure

  1. Mix one gallon of muriatic acid with three gallons of water (25% muriatic acid solution) in a five-gallon plastic bucket.
  2. Disconnect the water inlet and outlet hoses from the heat pump.
  3. Connect hoses as shown in the diagram. Note flow is in the opposite direction of the regular flow.
  4. Using a pump that will tolerate 25% muriatic acid, circulate solution through heat pump for 20 to 30 minutes.
  5. Flush with clean water.
  6. Reconnect water inlet and outlet hoses to the heat pump.

Source: Bosch Service Bulletin