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709-HP3W SeeLeveL II™ Tank Monitor System



See product descriptions for more information.


Please select one of the following sender combinations totaling 3 senders for your SeeLeveL RV Gauge system.

6″ sender (710JS)

12″ sender (710ES)

16″ sender (710SS)

Product Overview

The 709-HP3W tank monitor system is designed for accurate level measurement of motorhomes and trailer holding tanks. This system monitors battery voltage, three holding tanks, fresh, grey, and black water levels as well as the LPG tank. The level in percent is shown on a three digit LED display. This model includes a 3-way pump switch and a single-pole water heater switch on the display panel.

System includes:  1 display monitor, 3 – 12″ 710ES tank senders and 1 pigtail.

Note:  The standard 12″ 710ES senders may be swapped out for either the 7” 710JS and/or 16” 710SS senders (710SS sender is an additional cost).  Select the checkbox above to configure this option.

  • Full featured system for either OEM or retrofit applications
  • Provides accurate tank level information using percentage of full readout
  • Tanks are monitored using Garnet’s proprietary external level sensing technology. This ends fouling problems caused by debris build-up in the holding tank.  Detailed diagnostic information monitors sender operation.
  • Measures tanks up to 12 inches tall with a single sender or 24 inches tall with dual senders.  The 710JS sender option gives improved accuracy for tanks from 5” to 7” tall.
  • Tank senders connect to display via a common bus which saves wiring costs
  • LPG tank connection compatible with existing electric senders
  • Uses common industry connector for ease of installation and servicing

Resolution:  3/8 inch (10 mm)

Accuracy:  +/- 8% or better, limited by resolution and tank shape

Operating temperature range:  +32 to +140 °F (0 to + 60 °C)

Sender materials:  0.008” thick glass epoxy circuit board with conformal coating for circuit protection.  Laminated on the back with 3M 300LSE Bonding Adhesive.

Sender length range:  4-1/2 to 12 inches, which will measure tank heights from 5” to 14” (single sender) and up to 26” (dual senders).

Display mounting panel:  Black flush mount panel, approximately 4” wide by 2.8” high by 1” deep (102mm wide X 71mm high X 25mm deep).  Panel screws to wall.  Required cutout size is 3” wide by 1.8” high.

System power requirements:  Display requires 12 volts from the RV battery, the system will function from 11 volts to 16 volts.  Current drain is less than 200mA.

Wiring:  A single two wire conductor required from the display to the senders. All the senders are wired in parallel. 12 V power and ground required for display. Single wire required for LPG sender if sender grounded at tank.

LPG:  Display will work with an LPG sender with a maximum resistance of 50 ohms to 500 ohms.  Display shows increasing level as resistance increases.  System must be calibrated with the LPG tank full, or it can be factory calibrated.

Pump & Heater Switches:  The pump and heater switches are rated for a maximum of 10 amps. A relay is required if more amperage is needed. We recommend using a 10 amp fuse with the switches.