GRUNDIG Smart WiFi Tank Level Monitor — Ultrasonic Water & Liquid Sensor with App Alerts for RV, Home, Farm & Marine

I. About GRUNDIG Smart WiFi Tank Level Monitor

Stop climbing onto the roof to check your water tank. The GRUNDIG Smart WiFi Tank Level Monitor uses ultrasonic sensing to track your tank level in real time — and sends it straight to your phone. Works on freshwater, gray water, black water, diesel, and oil tanks for RVs, homes, farms, and marine use. Set custom high and low alerts and get push notifications the moment a tank needs attention.

II. Features & Applications

Real-Time Smartphone Monitoring

View your tank level from anywhere in the world using the free Tuya Smart or Smart Life app (iOS & Android). No subscription fees, ever.

Ultrasonic Precision, Non-Contact

Measures liquid levels from 4 in to 55 in (10 cm to 1.4 m) with ±1 mm accuracy at 25°C. No floats, no probes, no contact with the liquid — works with freshwater, diesel, oil, coolant, chemicals and more.

Custom High & Low Alerts

Set your own alarm thresholds and receive push notifications when the level hits a critical point. Prevent overflows before they happen, and never run your RV water pump dry again.

Built for Outdoor & Industrial Use

IP65/IP66 waterproof rating, wide temperature tolerance (-10°C to 70°C / 14°F to 158°F ambient; -20°C to 80°C medium), and corrosion-resistant polycarbonate housing. Designed for roof-mounted tanks, exposed installations, and tough environments.

Dual-System Architecture

Ultrasonic sensor mounts on the tank. Gateway plugs in near your router. Sensor ↔ Gateway via RF433MHz (up to 984 ft / 300 m open air, penetrates 3 walls). Gateway ↔ Cloud via 2.4GHz WiFi. Data in your app in seconds.

Built-In LED Display

Unlike basic sensors that only work through the app, this unit has a display right on the sensor showing the current level at the tank itself.

Expandable to Multiple Tanks

One app manages up to 10 sensors. Monitor freshwater, gray water, black water, fuel, and chemical tanks from a single dashboard.

Industry-Standard Smart Platform

Tuya Smart is one of the world's largest IoT platforms, compatible with Amazon Alexa and Google Assistant for voice control. Free app, trusted by millions.

Where It Works

• RV / Camper / Motorhome — freshwater, gray water, and black water holding tanks. Know your levels without stepping outside, especially when boondocking.
• Home water tanks — no more climbing onto the roof.
• Farm / Ranch — livestock watering tanks, fuel storage, irrigation reservoirs.
• Marine / Boat — fuel and water tank levels from the cabin.
• Industrial — chemical tanks, coolant reservoirs, oil drums.
• Generator fuel tanks — low-fuel alerts before power cuts out.

III. Package & Compatibility

Compatible Liquids

• Fresh water
• Diesel fuel
• Engine oil
• Hydraulic oil
• Coolant / antifreeze
• Chemical liquids
• Wastewater

Not recommended for viscous liquids, liquids with heavy sediment, or foam-producing liquids.

What's in the Box

• 1 × Ultrasonic level sensor with LED display
• 1 × RF433 wireless gateway
• 1 × AC/DC power adaptor (US plug)
• 1 × Mounting gasket
• 1 × Set of self-tapping screws
• 1 × User manual

IV. Installation & Setup

1. Clean the top center of your tank and attach the included gasket.
2. Drill a hole (55 mm / 2.2 in diameter or larger) at the marked center point.
3. Place the sensor over the gasket, aligned with the screw holes.
4. Fasten with the self-tapping screws. Do not overtighten on curved surfaces.
5. Connect the sensor to the power adaptor.
6. Place the gateway near your router and power it on.
7. Download the Tuya Smart or Smart Life app (iOS & Android, free). Press and hold the gateway's touch button for 5 seconds until the WiFi LED flashes, then follow the in-app steps to pair.
8. Input your tank height in the app for accurate percentage readings. Pre-calibrated — ready to use out of the box.
9. Done. Real-time tank levels, custom alerts, and multi-tank management are now live on your phone, from anywhere.

V. FAQ

Q1: Do I need WiFi for this to work?

The gateway requires a 2.4GHz WiFi connection to send data to your phone. The sensor communicates with the gateway via RF433MHz, which works independently — and the built-in LED display on the sensor always shows the level, even without WiFi.

Q2: Can I use this with diesel or oil tanks?

Yes. The ultrasonic sensor works with diesel, engine oil, hydraulic oil and many other non-corrosive liquids. It uses sound waves to measure the distance to the liquid surface and is not affected by color or conductivity.

Q3: How many sensors can I run at once?

One gateway supports multiple sensors, and one app account manages up to 10 sensors across different tanks — ideal for monitoring freshwater, gray water, black water, and fuel all from one dashboard.

Q4: What happens if the power goes out?

The sensor and gateway reset automatically when power is restored. No manual reconfiguration needed.

Q5: Does the sensor require calibration?

No — it comes pre-calibrated. Simply input your tank height in the app for accurate percentage readings.

Q6: Will it work with a metal tank?

Yes. The ultrasonic sensor mounts on top of the tank and measures the liquid surface from above. Works with plastic, metal and fiberglass tanks.

Q7: What size hole do I need to drill?

55 mm / 2.2 in diameter or larger, centered on top of the tank.

Q8: What liquids should I avoid?

We do not recommend viscous liquids, liquids with heavy sediment, or foam-producing liquids, as they can interfere with ultrasonic readings.