Installing Contactless Tank Sensors (S1–S4)

Overview

TankMaster uses external, contactless sensors mounted to the outside of the tank to measure liquid levels.
Proper sensor placement and mounting are critical for accurate and stable readings.

When You Need This

• First-time installation
• After a sensor has been moved or replaced
• If readings jump, skip levels, or become unstable

Understanding Sensor Positions (S1–S4)

Each TankMaster supports up to four sensors, labeled:

• S1 – Lowest sensor (near empty)
• S2 – Lower-mid level
• S3 – Upper-mid level
• S4 – Highest sensor (near full)

Sensors must be installed in ascending order from bottom to top.

Choose Sensor Locations

• Mount sensors on a flat section of the tank wall
• Avoid ribs, seams, or molded contours
• Do not mount over internal baffles or fittings
• Keep sensors aligned vertically
• Leave at least 1–2 inches between sensors

Important: Sensors must be mounted on the side wall of the tank, not the bottom.

Clean the Tank Surface

1. Clean the tank surface with isopropyl alcohol
2. Remove dirt, grease, or road grime
3. Allow the surface to dry completely

Poor surface preparation is the #1 cause of unstable or jumping readings.

Mount the Sensors

1. Peel the backing from the adhesive pad
2. Press the sensor firmly against the tank wall
3. Hold pressure for 20–30 seconds
4. Do not move the sensor once installed

The sensor must sit flush against the tank wall with no air gaps.

Adhesive & Mounting Notes

• Ensure the entire sensor face contacts the tank
• Air gaps will cause readings to jump or skip
• If a sensor falls or loosens, remove it and clean both surfaces before remounting

Routing Sensor Cables

• Route cables upward to prevent water drip paths
• Avoid sharp edges or pinch points
• Leave a small service loop at each sensor

Allow Adhesive to Set

For best results:

• Allow at least 10–15 minutes before moving cables
• Avoid tank use for 1 hour after installation if possible

Special Notes for Black Tanks

• Black tanks are often thicker than fresh or gray tanks
• Sensor sensitivity may need adjustment
• Ensure sensors are not mounted over reinforced areas

Common Problems & Fixes

Readings Jump from 0% → 25% → 90%

• Sensor is not fully adhered
• Air gap between sensor and tank wall
• Dirty or uneven mounting surface

Sensor Worked at First, Then Failed

• Adhesive loosened due to dirt or moisture
• Sensor shifted after installation

Fix: Remove the sensor, clean the surface, and remount using fresh adhesive.

Tips for Best Results

• Install sensors with an empty tank when possible
• Double-check placement before removing adhesive backing
• Mount all sensors in one session

Next Steps

• Power on the TankMaster
• Pair the app via Bluetooth
• Verify sensor detection
• Adjust sensitivity if needed

Related Articles

• Mounting the TankMaster Sending Unit
• Adjusting Sensor Sensitivity
• Tank Readings Jump or Skip Levels
• Best Double-Sided Tape for Sensors