Troubleshooting & Cleaning a DriSteem Humidifier Probe Assembly

Brad Notter
October 29, 2019
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If you have a DriSteem steam humidifier (including the Vaporstream, Vapormist or GTS model operating on standard softened or potable water) you need to periodically clean the probe assembly.

You may notice an alarm on the display stating one of the following:

Dri-Steem Humidifier Probe

  • Faulty water probe
  • Excess till time
  • Excess refill time

You may also notice the display showing Filling all of the time and possibly the unit cannot keep up with the humidity set point.

These faults and displaying Filling all of the time are most commonly caused by a dirty or oxidized probe assembly. The steam generator will need to be turned off and partially drained before proceeding with the probe removal. Please follow all safety procedures in the manual before proceeding.

Cleaning the Dri-Steem Humidifier Probes:

  1. Access the probe assembly either from the electrical panel or by removing the roof panel above the electrical area.
  2. Disconnect the probe plug and cable assembly and unscrew the probe rod assembly from the humidifier probe housing.
  3. Inspect the probe housing and clean, ensuring that all the housing passageways are clear. Remove the housing from the tank by removing the cover plate from the tank.
    • The Probe housing can also be cleaned by scraping the scale off and vacuuming it out.
    • The scale should flake off easily from the probe assembly rods.
    • The bottom 3/8″ (10 mm) of each rod is the sensing portion; clean these areas with a wire brush, abrasive pad, or steel wool.
  4. Inspect the composite plastic probe rod assembly for any signs of cracking, roughness, or deterioration. If found, replace probe assembly.
  5. Reassemble the probe assembly.
  6. Restart the unit per the manual.

Note that the probe cleaning is only a portion of the normal periodic maintenance that needs to be completed on your steam generator.

DriSteem does offer a probe removal tool that makes removal and reinstallation of the probe a simple procedure. This is included in the service kit as described below.

If you are interested in completely cleaning and servicing the steam generator, please contact us for a service kit which contains the:

  • probe tool
  • probe assembly with gasket and housing
  • clean out gasket
  • cover gasket and other service items

DriSteem also offers a de-scaling solution and a complete de-scaling system with pump in kit form.

Preventing Scale Build Up On Steam Humidifiers

Scale buildup on steam humidifier heaters acts as an insulator, reducing humidifier performance while increasing energy costs. To keep humidifiers operating as efficiently as possible, remove scale with DriSteem’s Humidifier De-scaling Solution, available for purchase from R. L. Deppmann.

The De-scaling Solution cleans without risk of corroding humidifier tanks or welds, it also cleans surfaces unreachable by hand scraping. DriSteem’s Humidifier De-scaling Solution is the only approved cleaner/de-scaler for use with DriSteem humidifiers. Use of other cleaners/de-scalers may void your DriSteem warranty.

We will need your model and serial number to provide the correct service kit, De-scaling Solution or De-scaling Kit for your unit.

Contact R. L. Deppmann to ensure your humidification system performs at its maximum ability.

Learn more about the Dri-Steem Humidified and De-Scaling Pump Kit:

Video sourced from

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