Skip to main content

Convection Steam Oven Water Requirements


  • Use of demineralized, filtered, or distilled water
  • What kind of water is required to operate a Convection Steam Oven (CSO)?
  • Water heavy in minerals
  • Lowest recommended water hardness in grains
  • How much water is needed to fill the tank?


The Wolf Convection Steam Oven (CSO) requires minerals to be present in the water to work properly. Do not use demineralized, reverse osmosis filtered, or distilled water.

  • The unit contains an electromagnetic level sensor to measure the flow of water into the boiler.
  • This type of technology requires mineral content in the water for accurate measurement.
    • Tap water, filtered water, and softened water can all be used in the Convection Steam Oven, as long as there are minerals in it. 
    • Bottled water will work in the Convection Steam Oven.
  • To maintain proper function, always test the water hardness first with the water test strip provided with the product.
  • The CSO contains an external boiler that reduces mineral buildup. Run the Descale program when the CSO reads "Boiler scaled up, please descale!"
    • Refer to Convection Steam Oven Descaling for more information about descaling, including descaling solution recommendations and instructions for the process.

Refer to the product Use and Care Guide for further information.

See also:


Need further assistance? Contact Customer Care at 800.222.7820 or provide your information below and request a Customer Care representative contact you.

Ask Your Question

We're standing by with answers

Whether you're shopping for appliances or have questions about those you already own, we've got the resources you need. Talk directly to a customer care expert at the Sub-Zero, Wolf, and Cove service center, or connect with an appliance consultant at an official showroom near you. Get quick answers online, or reach a certified service provider or installer. And much more.


Call us at (800) 222-7820