What Does a Tank Alarm Do?

In this article, we’re going to go over the basics of tank alarms. We’ll describe what a tank alarm does, the different types that exist, available alarm features and how a typical system works. Let’s get started!

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What Does a Tank Alarm Do?

Tank alarm systems alert you to a critical water level in a tank before it becomes a problem, whether it’s a high level or low level condition. This will depend on the application. They typically consist of audible and visual indication. SJE Rhombus tank alarms can be either 120 or 240 VAC. They also come standard with a control switch.

low level alarm float

Most tank alarms can be used as either low or high level alarms. When provided with a normally closed control switch, the alarm acts as a low level alarm. Low level alarms alert the user when the tank level goes too far down, triggering the low level alarm float.

high level alarm float

When provided with a normally open control switch, the alarm acts as a high level alarm. High level alarms alert the user when the tank level goes too high, triggering the high level alarm float.

Indoor vs. Outdoor Alarms

Alarms are designed for either indoor or outdoor use. Indoor alarms should never be used for outdoors applications, as the enclosures aren’t designed to keep out environmental factors like water or pests. These types of alarms are rated as NEMA 1 for indoor use. Outdoor alarms are safe for either indoor or outdoor applications. There are 2 types of outdoor ratings to look out for: Type 3R and NEMA 4X. Type 3R is the least demanding rating. It offers protection from falling dirt, rain, sleet and snow. NEMA 4X offers superior protection from corrosion and extreme environments, including windblown dust and rain, and splashing or hose-directed water.

Alarm Features

xpert alert wifi tank alarm

All SJE Rhombus alarms come standard with a visual alarm, audible alarm and test/silence switch. Tank alarms with a remote notification option are becoming more popular because of their convenience. These alarms use WiFi or ethernet to notify the user of an alarm condition via text and/or email, in addition to the local audible and visual alarm. Our Xpert Alert® WiFi is an indoor alarm that uses your existing internet connection to send you notification messages. It’s perfect for cabins or vacation homes where the user might not always be around to hear or see an alarm condition.

Our Xpert Alert® RF alarm system uses wireless radio technology to connect an outdoor control panel with an indoor alarm, providing the convenience of indoors and even remote notification. It works at a distance of up to 200 feet, meaning there’s no need to install underground wires.

tank alert solar alarm

Solar-powered alarms are another useful option. Our Tank Alert® Solar alarm uses a 10-watt solar panel and rechargeable battery to provide power to even the most remote or off-grid systems.

Other features you might want to consider when selecting an alarm:

  • A low temperature indicator to warn of possible freezing pipe conditions
  • 2 alarm inputs to monitor 2 different levels
  • A 9VDC touch safe float circuit
  • An automatic alarm reset
  • Battery backup
  • You might also want to consider the product’s warranty. SJE Rhombus offers an industry-leading 5-year limited warranty on all our alarms.

How Tank Alarms Work

Now let’s look at the operation of a standard septic system with a pump and a high level alarm. First we’ll demonstrate the conditions that cause the pump to turn on. Currently the water level is low and the pump is off. As water enters the tank, the level rises. When the pump switch tips up, the pump turns on and pumps out the water. As the pump runs and the water level drops, the pump switch drops down and the pump shuts off.

tank alarm in alarm condition

In this next example, we’ll demonstrate an alarm condition. Here, as the water level rises and turns the pump on, the pump is unable to keep up with the volume of water flowing into the tank. The pump will be running, but the water level continues to rise until it reaches the alarm float. Now the alarm float tips up, and the alarm alerts the homeowner to a potential problem. At this point, the homeowner can silence the audible alarm, but the red indicator will remain on until the problem is corrected. As the pump continues to run, the water level in the tank drops below the alarm float, and the alarm automatically resets. The pump will continue to run until the water level lowers the pump switch to shut off the pump.


Today we walked you through what a tank alarm does, what types exist, what features are available and how a typical system works. SJE Rhombus has a full range of tank alarms available to suit nearly any application. We even have an interactive tool to help you pick the right one!