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

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

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

Mount the Sensors

Peel the backing from the adhesive pad
Press the sensor firmly against the tank wall
Hold pressure for 20–30 seconds
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

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

Choose a Mounting Location

Select a location that meets all of the following requirements:

Inside the RV or inside an enclosed RV compartment

Will remain dry at all times

Within reach of all sensor cables (S1–S4)

Near a USB power source

Not exposed to direct spray, standing water, or road splash

Not exposed to extreme heat or condensation

Acceptable Locations:

Inside a basement storage compartment

On a wall or frame surface near the tank

Inside an enclosed utility bay

Important:
If mounted in a compartment that may experience moisture, the enclosure
must be sealed with silicone sealant around seams and cable entry points.