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A water level controller can make a rainwater tank much easier to manage. It can start a pump when a tank fills, stop a pump before the tank runs dry, or control water transfer between two tanks.
There is no single best water level controller company for every setup. For most homeowners, the better choice is the company that makes a controller suited to the tank, pump, sensor type, voltage, and installation location.
As of September 2026, Omron is a strong place to start for dedicated water-level control, especially when you want electrode-based or "floatless" control. Schneider Electric is another strong choice for panel-mounted liquid-level relays and more industrial pump-control setups. Both companies currently offer equipment specifically designed for liquid-level applications.
For a simple rain barrel, IBC tote, or garden tank, however, you may not need an industrial controller at all. A properly rated float switch and pump-control setup can be simpler.
What Makes a Water Level Controller Company Good?
The company name matters less than whether its controller fits the job.
Before choosing one, check these five things:
- How the controller senses water
- What voltage powers it
- What kind of output it provides
- Whether it can safely control your pump
- Whether its enclosure suits the installation area
A controller that works well in a factory control panel may be a poor choice beside an outdoor rainwater tank.
Likewise, a basic float controller may be fine for garden irrigation but too limited for a system that transfers water between several cisterns.
Omron Is a Strong Choice for Dedicated Level Control
Omron has a broad range of controllers made specifically for detecting and controlling liquid levels.
Its current 61F line includes several types of floatless level controllers. Different versions are available for different installation methods, liquids, wiring arrangements, and control needs. Omron also publishes a water-level controller selection guide.
A floatless level controller usually uses metal electrodes rather than a moving float. The controller detects whether water is touching the electrodes by measuring electrical conductivity.
This approach can work well for:
- Storage tanks
- Pump dry-run protection
- Filling tanks automatically
- Emptying tanks automatically
- Transfer systems between tanks
- Pump control panels
Omron also offers controllers for alternating two pumps, which may be useful in larger systems where pumps share the workload.
The Main Limitation of Electrode Controllers
Electrode sensing depends on the electrical properties of the liquid.
That matters with rainwater.
Rainwater conductivity can change depending on roof debris, dissolved minerals, tank conditions, treatment, and other factors. Very low-conductivity water may require a controller designed for higher sensitivity. Omron, for example, makes high-sensitivity versions intended for difficult liquids, including very pure water.
Do not assume that any electrode controller will work correctly with every rainwater system.
If you want simpler level detection that does not depend on water conductivity, a mechanical float switch may make more sense.
Schneider Electric Is a Strong Choice for Control Panels
Schneider Electric is another established option, especially when the water-level controller will become part of a larger electrical control system.
Its current Harmony and Zelio control-relay ranges include liquid-level monitoring relays. For example, the RM22-L series is intended for applications that include pumping and water systems.
This type of equipment can make sense when you have:
- A dedicated pump-control panel
- A contactor controlling the pump
- Multiple sensors
- Alarms
- Automatic filling or draining
- Other control relays
- More complex electrical equipment
Schneider may therefore be a better fit than a simple tank controller when the water system is part of a larger electrical installation.
Omron vs. Schneider Electric
Neither company wins every situation.
| Situation | Better starting point |
|---|---|
| Dedicated electrode water-level control | Omron |
| Simple pump filling or draining control | Omron or Schneider |
| Industrial control panel | Schneider Electric |
| Integration with other control relays | Schneider Electric |
| Multiple specialized conductive sensing options | Omron |
| Simple rain barrel or garden tank | A simpler float system may be enough |
This is a starting point rather than a compatibility guarantee.
The exact controller still needs to match your pump, power supply, sensors, and control method.
Do You Even Need a Floatless Controller?
Not always.
For many rainwater systems, the simplest reliable solution is a float.
A float switch is a switch that changes position as the water level rises or falls. Some hang from a cable. Others slide on a stem or attach to the tank wall.
Float switches are often useful for:
- Stopping a pump when a tank gets too low
- Starting a transfer pump when a tank fills
- Preventing an receiving tank from overflowing
- Maintaining water between two levels
They do not normally depend on water conductivity.
Their main weakness is that they have moving parts. Sediment, tank walls, pipes, cables, or other objects can interfere with their movement.
For a basic rainwater tank, that tradeoff may still be worthwhile because the system is easy to understand and troubleshoot.
Match the Controller to the Pump
This is one of the most important checks.
Do not assume that because a controller has a relay output, you can connect a large pump directly to it.
A pump motor can draw much more current when it starts than during normal operation. The controller's output must be suitable for the electrical load and control arrangement.
Larger pumps commonly use a contactor. A contactor is an electrically operated heavy-duty switch. The water-level controller tells the contactor when to turn on or off, while the contactor handles the pump's electrical load.
The controller, contactor, motor protection, wiring, voltage, and pump must all be compatible.
If you are dealing with mains voltage, a large pump, or a permanent pump-control panel, this is a good point to involve a qualified electrician.
Choose the Right Sensing Method
Different controller companies may specialize in different sensing methods.
Float switches
Best when you want something simple.
They physically move with the water level and operate a switch.
Conductive probes
Best when you want no moving float inside the tank and the water has suitable conductivity.
Metal electrodes detect whether water has reached certain levels.
Omron's floatless controllers are a common example of this approach. The company describes its conductive level controllers as detecting liquid by measuring resistance between electrodes.
Pressure sensors
These estimate water depth from the pressure created by the water above the sensor.
Explore a suitable automatic water level controller to compare this choice in the broader collection layout.
They can provide more than simple full-or-empty information, but they require suitable electronics and calibration.
Ultrasonic sensors
These measure the distance from a sensor to the water surface without touching the water.
They can work well for continuous level monitoring, but tank shape, condensation, obstructions, foam, and sensor placement can affect performance.
For a homeowner who only needs "pump on" and "pump off," this level of complexity may not be necessary.
Check the Installation Environment
Rainwater systems often put electrical equipment close to moisture.
That deserves careful attention.
Equipment installed in damp or wet locations needs to be intended for those conditions. OSHA electrical rules, for example, require equipment in wet locations to be suitable for that environment and require weatherproof enclosures for switches and similar electrical equipment in wet locations.
Look at the enclosure rating rather than assuming a plastic box is waterproof.
NEMA enclosure types describe different levels of environmental protection. For example, NEMA Type 4 and 4X enclosures provide protection against rain, snow, splashing water, and hose-directed water, while Type 4X also adds corrosion protection.
IP ratings are another enclosure classification system. They are defined under IEC 60529. NEMA notes that NEMA and IP ratings are not directly interchangeable in every situation because NEMA ratings cover some conditions beyond water and dust ingress.
The rating needed for your installation depends on exactly where and how the equipment is mounted.
Look for Proper Certification and Documentation
A reputable controller manufacturer should make it easy to find:
- Wiring diagrams
- Supply-voltage requirements
- Sensor requirements
- Relay or output specifications
- Operating limits
- Installation instructions
- Enclosure information
- Troubleshooting information
For equipment sold in markets where third-party electrical certification applies, also check the actual certification rather than relying on a seller's description.
UL explains that certified products can be verified through its Product iQ certification database.
A recognizable company name does not remove the need to verify the exact model.
Think About Dry-Run Protection
If the controller operates a rainwater pump, low-water protection is often more important than knowing whether the tank is completely full.
A pump that continues operating without enough water may overheat or become damaged, depending on its design.
A useful system may therefore have two different functions:
- A normal operating level that tells the pump when to run.
- A low-level cutoff that stops the pump before the tank becomes too empty.
Some pumps include their own dry-run protection. Others depend on an external switch or controller.
Check the pump instructions before deciding which component should provide this protection.
Do Not Forget Overflow
A water level controller should not be your only overflow protection.
Rainwater tanks normally need a properly sized physical overflow path even when an automatic controller manages pumps or valves.
Electrical components can fail. Sensors can become dirty. A float can stick. Power can go out.
The tank should still have a safe place for excess water to leave without depending on the controller.
What About Smart Wi-Fi Water Level Controllers?
Remote monitoring can be useful, but Wi-Fi should not replace basic protection.
For example, you might use a smart level sensor to see tank level on your phone. That can help with irrigation planning or checking a remote cistern.
But critical pump protection should not depend only on:
- Internet access
- A cloud service
- A phone app
- Wi-Fi coverage
Local controls should still protect the pump and tank when the network is unavailable.
Also check whether the company provides documentation for how the controller behaves after a power failure, sensor failure, or lost connection.
Which Company Should You Choose?
For a dedicated electrode-based water-level system, Omron is one of the strongest companies to consider first. Its current product range is specifically built around liquid-level detection and includes several controller types for different water-control situations.
For a controller being installed inside a larger electrical or pump-control panel, Schneider Electric is also a strong choice. Its current control-relay lineup includes liquid-level relays intended for pumping and water applications.
For a small rainwater tank, however, neither may be necessary. A properly selected float switch and pump-control arrangement can be simpler and easier to maintain.
Start with the system rather than the logo. Determine:
- What water level you need to detect
- Whether you need filling, draining, or both
- What type of sensor you want
- Your pump voltage and control requirements
- Whether dry-run protection is needed
- Whether the controller will be indoors or outdoors
- What happens if the controller fails
Once those details are clear, choosing the company becomes much easier.
Frequently Asked Questions
Is Omron a good company for water level controllers?
Yes. Omron currently offers a broad range of dedicated floatless level controllers, including models for different sensing conditions and pump-control applications. It is particularly worth considering when you want conductive electrode sensing.
Is Schneider Electric good for water tank controllers?
Yes. Schneider Electric offers liquid-level control relays that can be integrated into pump and electrical control panels. It can be a good fit when level control is one part of a larger electrical system.
Is a float switch better than a water level controller?
It depends on the job. A float switch is often simpler for basic on-and-off control. An electronic controller can provide more control options, multiple sensing points, alarms, or integration with other equipment.
Can a water level controller run a pump directly?
Sometimes, but not always. The controller's output must be suitable for the pump load. Larger pumps commonly require a contactor or other motor-control equipment. Never assume a small control relay can safely carry a pump motor's current.
Are electrode water level controllers suitable for rainwater?
They can be, but electrode controllers depend on the electrical conductivity of the water. Rainwater conductivity can vary, so the controller and probes must be suitable for the actual conditions.
Can I install a water level controller outdoors?
Only if the controller and enclosure are suitable for the location. Rain, condensation, splashing water, corrosion, wiring entry points, and temperature all need to be considered. Electrical equipment near water should be installed conservatively and in accordance with applicable requirements.
Do I still need a tank overflow if I have an automatic controller?
Yes. The tank should have a physical overflow route. A controller, sensor, pump, or power supply can fail, so overflow protection should not depend only on electrical equipment.
