Topics:

• Descale Legacy Convection Steam Oven with knob controls
• Best product to use when descaling oven cavity of Legacy Convection Steam Oven
• Why is the interior of a Convection Steam Oven discolored?
• How long does descaling take in a CSO?
• How often to run descale program
• Remove internal water system for cleaning

Answer:

This information is for Legacy CSO models with a knob. For CSO models with touch controls, refer to:

• Legacy Convection Steam Oven (Touch Control) Descaling Instructions.
• Convection Steam Oven Descaling Instructions

Cleaning Procedures

Lime deposits are a natural result of steam creation and will slowly build up inside of the unit's boiler and water lines. Depending on water hardness and usage, the unit should be descaled every 6-18 months to remove build-up. ​Descaling more frequently will not harm the unit.

Things to know before descaling:

• Durgol® is the only recommended descaling solution at this time. Other products and substances can cause permanent damage to the unit. For use and purchasing information, see Convection Steam Oven Descaling Solution.
• Descaling requires emptying and filling the water tank several times throughout the cycle. Plan to be present for the entire descaling cycle.
  • Descaling takes about 45 minutes if only one rinse cycle is needed. If the unit determines more rinse cycles are necessary, then the time needed will increase up to an additional 30 minutes.
  • For safety reasons, the descale program cannot be interrupted or stopped once it is started.
• Descaling does not clean the oven interior. Descaling removes mineral deposits from the mechanical parts of the unit. It is not necessary to remove racks or pans for descale cycle. See also, Legacy Convection Steam Oven Cleaning Information.

To descale:

1. With the oven off, press OK.
2. Turn the knob to Descale, then press OK.
3. "Descale Appliance" appears. Press OK.
4. "Start" appears. Press OK.
   • The display shows a message "Add 1 pt (0.5 L) of descaling solution—and press OK."
5. Remove the water tank and empty it if it has water in it.
6. Pour the entire Durgol® Swiss Steamer descaling solution contents into the tank. Do not dilute.
7. Install the water tank and press OK. "Descale Running" appears on the display.
   • If "Descale Running" does not appear, verify the water tank is installed and seated properly.
8. After 30 minutes, "Pour away descaler. Add 2 pt (1 L) water" appears on the display.
9. Remove the tank, turn on the faucet, and pour descaling solution down the drain.
   • Failure to dilute descaling solution before discarding may discolor sink and drain.
10. Fill the tank with warm tap water and reinstall.
    • Demineralized, reverse-osmosis filtered, or distilled water should not be used in the oven. Refer to Convection Steam Oven Water Requirements for more information.
    • "Descale appliance—1st rinsing cycle" appears on the display.
11. About 15 minutes later, "Pour away water—Descaling completed" appears on the display.
    • Depending on the level of soil in the rinse water, the oven will determine whether additional rinse cycles are necessary.
    • "Repeat 1st rinsing cycle," "2nd rinsing cycle," or "Repeat 2nd rinsing cycle" will appear if the unit determines the extra rinse cycles are necessary.
12. As soon as “Pour away water—Add 1 L water” appears on the display, refill the tank with fresh, warm tap water and reinsert the tank.
    • The rinsing phase starts automatically. "Descale appliance - 2nd rinsing cycle" appears on the display.
    • After about 30 minutes, "Pour away water - Descaling completed" appears on the display.
    • No steam is produced during descale before the final rinse. During the final rinse, steam may be produced as water is added to flush the descale out. This is normal.
13. Once the rinse cycles are complete, remove, empty, and dry the water tank. Wipe all stainless steel surfaces.
    • The internal water system cannot be removed and cleaned.
14. If the descaling prompt returns after descaling is complete, descale once again.
15. If the message has returned twice, contact Factory Certified Service to schedule an appointment for repair.

• Convection Steam Oven Discoloration