The Garnet 709-P3W SeeLevel II is the industry-leading RV tank monitoring system trusted by over 200,000 RV owners – now with LP propane monitoring included. Unlike factory-installed monitors that show vague quarter-tank increments (and often show "full" when you're not), the SeeLevel II displays actual percentage levels from 0% to 100% in 5% increments. Never run out of propane in the middle of a cold night again!3 Tanks + LPG% ReadoutPump Switch
0-100% in 5% increments
Know your propane level
No fouling, no false readings
Built into display panel
With multiple models available, choosing the right SeeLevel II system can be confusing. Use our SeeLevel II Comparison Guide to find the perfect match for your RV's tank configuration and feature requirements.
One of the best features of the SeeLevel II system is the ability to add additional monitors at other locations in your RV. The common bus wiring allows you to connect multiple displays to the same sensor network. Popular second display locations: • Bedroom or bathroom for overnight monitoring • Outside water bay for convenient dumping • Cockpit area for quick checks while traveling • Near the galley for water conservation awareness Simply purchase an additional 709-P3W Monitor Only and wire it to your existing sensor network – no additional sensors needed!
The 709-P3W adds LP gas monitoring to the complete water tank monitoring package. Nothing ruins a camping trip like waking up freezing because you ran out of propane overnight. With the 709-P3W, you'll always know exactly how much propane remains.
How LPG monitoring works: The SeeLevel II connects to your RV's existing propane tank sender (the sensor built into your LP tank gauge). Most RVs with permanent mounted propane tanks include a sender unit – look for wiring coming from your tank's gauge. The display connects via the green wire and shows propane level as a percentage after a simple calibration with a full tank.
Your propane tank must have an existing sender/sensor (sometimes called an LPG gauge sensor, remote ready dial, or R3D dial). The SeeLevel II does NOT include a propane sensor – it connects to your RV's existing one. Most RVs with built-in (non-removable) propane tanks have this sender already installed. Note: Portable DOT cylinders (20lb BBQ-style tanks) typically do NOT have senders and cannot be monitored with this system.
Traditional RV tank monitors use probes that extend inside the tank. These probes quickly become coated with waste residue, toilet paper, and struvite buildup – causing the dreaded "always shows full" problem that plagues nearly every RV owner.
The SeeLevel II difference: Sensors mount externally on the tank wall using 3M adhesive. They measure tank levels through the plastic tank wall using capacitive sensing technology. No probes inside the tank means:
• Battery Voltage: Know when batteries need charging • Fresh Water Tank: Know exactly how much water remains • Grey Water Tank: Plan showers and dishwashing accordingly • Black Water Tank: Know exactly when to dump – no guessing • LP Propane Tank: Never run out of gas unexpectedly • Water Pump: 3-way pump switch built into display panel
Garnet offers three sensor sizes to match your tank heights. Sensors can be cut shorter or stacked for taller tanks:
Tip: The 710-ES3 (12") is the most popular choice and fits most standard RV tanks.
SeeLevel II water tank sensors work on plastic/polyethylene and fiberglass tanks only. They will NOT work on metal tanks. Tank walls must be 3/8" (10mm) thick or less. The sensors measure water-soluble liquids only. Note: LPG monitoring connects to your existing propane tank sender – it does not use adhesive sensors on the metal propane tank.
Most RV owners can install the SeeLevel II system themselves. The hardest part is accessing your tanks – the actual installation is straightforward:
Complete installation instructions included. Professional installation recommended if you're uncomfortable with electrical work.
• LPG tank sender (must use existing sender in your RV's propane tank)
Want to check tank levels from the bedroom, bathroom, or wet bay? Simply add a 709-P3W Monitor Only to your system. Multiple displays can share the same sensors via the common bus wiring – no additional sensors required!
Sensors can be trimmed shorter or stacked for taller tanks. Don't mix sensor types when stacking.
Choose 709-P3W if you want propane monitoring. Choose 709-P3 if you don't need LPG monitoring or don't have an existing propane sender.
→ View Complete SeeLevel II Comparison Guide
Manual: 709 Series Manual Support: garnetinstruments.com/support Warranty: 1 Year Limited