Instructions for Mounting Thermistors on an Aqua-Hot 125D in a 144″ Wheelbase Sprinter with Two Heat Exchangers

Proper placement of thermistors ensures efficient temperature control and consistent heat distribution. Below is a guide for mounting thermistors when installing the Aqua-Hot 125D system in a 144″ wheelbase Sprinter with two heat exchangers.

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1. Understand the System

  • Thermistors: These sensors measure temperature and relay information to the Aqua-Hot system for maintaining desired heat levels.
  • Heat Exchangers: Typically mounted in separate zones, often one at the front and one in the rear of the van.

2. Tools & Materials Needed

  • Thermistors (provided with Aqua-Hot system)
  • Drill and drill bits
  • Zip ties or cable clamps
  • Electrical tape
  • Heat-resistant adhesive (if required)
  • Screwdriver set

3. Mounting Locations

Front Zone (Heat Exchanger #1)

  • Recommended Placement:
    • Near the lower passenger-side B-pillar or beneath the dashboard area.
    • Position the thermistor close to the heat exchanger but away from direct airflow to avoid inaccurate readings.
  • Mounting Steps:
    1. Identify a flat, clean surface near the heat exchanger location.
    2. Secure the thermistor with heat-resistant adhesive or screws, ensuring it is stationary and won’t shift due to vibrations.
    3. Run the wiring along existing harnesses, securing it with zip ties or cable clamps.

Rear Zone (Heat Exchanger #2)

  • Recommended Placement:
    • Near the rear heat exchanger, typically mounted in the cabin area or cargo zone.
    • Place the thermistor in a central location, such as on a side panel or near the rear wheel well, but away from direct airflow and drafts.
  • Mounting Steps:
    1. Clean the mounting surface to ensure the thermistor stays in place.
    2. Secure the thermistor near the rear heat exchanger in a position that allows it to read ambient cabin temperature.
    3. Route the wire back to the Aqua-Hot control panel, securing it along the frame or wall panel.

4. General Tips for Both Zones

  • Avoid Direct Heat Sources:
    • Do not mount the thermistors directly on the heat exchanger, as this will cause inaccurate temperature readings.
    • Ensure they are not exposed to direct sunlight or other heat-emitting components.
  • Ensure Proper Airflow:
    • Mount the thermistors in areas with steady, consistent airflow to provide accurate ambient temperature readings.
  • Protect the Wiring:
    • Use protective conduit if the wiring will be exposed to areas prone to abrasion or high heat.
    • Avoid routing wires near moving parts or sharp edges.

5. Final Steps

  1. Connect Thermistors to the Control Panel:
    • Follow Aqua-Hot’s wiring schematic to properly connect the thermistors to the system.
  2. Test the System:
    • Power on the Aqua-Hot system and verify that both thermistors provide accurate readings to the control panel.
  3. Secure All Wiring:
    • Double-check that all wiring is secure and neatly routed.

By mounting the thermistors in these recommended locations, your Aqua-Hot 125D system will efficiently monitor and maintain optimal temperatures across both zones in your 144″ wheelbase Sprinter. For further assistance, feel free to contact Aqua-Hot support or your installer.