Water flow sensor – the principle of operation, how to select and install the device

Monitoring the amount of water used in your house helps you avoid leaks and save money on resources in addition to lowering your utility costs. One useful tool for keeping an eye on water flow in your home is a water flow sensor. These sensors are essential in contemporary homes, helping with everything from leak detection to water usage optimization.

So, how do these clever devices operate? A water flow sensor’s basic method of operation is to measure how quickly water moves through a pipe or fixture. Usually, it’s made up of a rotating sensing mechanism—like a paddle or turbine—that detects when water passes through it. The flow rate is ascertained by interpreting the signals produced by this rotation. The sensor’s collected data can be easily accessed and analyzed by being displayed on a connected device or sent to a monitoring system.

There are a few things to take into account when choosing the best water flow sensor for your house. First, consider the pipe diameter and anticipated flow rates. Picking a sensor that meets your unique needs is crucial because different models are made to handle different pipe diameters and flow rates. Think about any extra features like temperature sensing or leak detection, as well as whether you need a wired or wireless sensor.

Although installing a water flow sensor might seem difficult, it’s actually very simple. The majority of sensors are simple to install into your current plumbing system and don’t require any major adjustments. Installing a sensor can be as easy as clamping it onto the pipe or as complex as integrating it into your plumbing system, depending on the kind you select. To guarantee accurate readings after installation, you’ll need to calibrate the sensor, which usually entails following the manufacturer’s instructions and modifying settings as needed.

Technical design and features of functionality

The water flow sensor on a gas boiler has one function, which is to measure the volume or amount of liquid passing through a calibrated cross-section, regardless of the layout that is employed. Boiler automation controls the gas flow rate to the burner device based on the signal from the water flow sensor.

The flow sensor’s accurate and reliable operation depends on:

1. Turning on the gas burner to heat the water in the gas boiler. In some cases, the DHW system will not work, for example, with a closed faucet. Similarly, the water flow sensor for a gas heater blocks its operation if the amount of liquid flowing through the heat exchanger is insufficient for safe heating.
2. Hot water temperature stabilization. Automation corrects the amount of heat depending on the water flow rate so that the flow temperature remains stable or changes by turning the adjustment knob on the control board.

This is actually one of the heating boiler’s primary control sensors. If the burner is not lit and the water is not heated after opening the faucet, the hot water supply is not working, which indicates that either the sensor or the main line’s pressure is malfunctioning.

The device is mounted on the cold side of the DHW heat exchanger in two-circuit boilers.

It is advisable to indicate the device’s name, primary features, and model (water flow sensor) before placing an order.

Manufacturers of gas heating boilers frequently produce their own brand of hot water flow sensor. As a result, a sensor from one company’s boiler equipment model won’t work with a competitor’s boiler unit.

Although it’s not quite accurate, this device is frequently referred to as a pressure sensor. There is an additional device in a gas boiler that regulates pressure. Although it’s already air, not water, it’s also known as a pressure sensor.

Difference between flow sensors and water pump pressure sensors

Control devices come in two varieties: those for pumps and boilers. Both in terms of the device and the operating principle, the differences are substantial. Both kinds of sensors have benefits and drawbacks, but generally speaking, they regulate the system based on the actual appearance of water flow rather than the pipeline’s inlet pressure.

1. The pump version of the sensor is designed to issue pump motor start authorization and lockout commands. The command from the working pair is directly fed to the starting relay. It is a reliable and durable design.
2. The flow sensor for boilers gives a constant signal about the state and value of the water flow. The information is fed directly to the input of the electronic control board.

The boiler’s sensor functions much like a water flow meter in general. As a result, the design is more intricate and vulnerable to the working element jamming or clogging. Additionally, in order to allow the sensor housing to be "squeezed" into the boiler, the majority of manufacturing companies design them to be as intricate and small-sized as possible.

In our article on water flow sensors, we delve into how these devices work and offer practical tips for selecting and installing them in your home. Water flow sensors are crucial for monitoring water usage and detecting leaks, helping to conserve water and prevent damage to your property. We explain the basic principle behind how these sensors operate, which involves measuring the rate of water flow through a pipe or plumbing system. We also provide guidance on choosing the right sensor for your needs, considering factors like flow rate, pipe size, and sensor type. Additionally, we walk you through the installation process, offering step-by-step instructions to ensure proper placement and functionality of the device. With our article, you"ll gain a clear understanding of water flow sensors and how to effectively implement them in your home for improved water management and peace of mind.

Varieties of the model range

It is essential to comprehend the operation of a water flow sensor to prevent confusion with various models.

Water flow can be measured in several ways. The simplest option is to use a plate installed across the direction of water flow. When the tap is opened, the flow will run over the surface, exerting pressure, which will deflect the plate and close it with the contact pair.

This electromagnetic relay scheme is used. The only distinction is that the electromagnetic field, rather than the water flow inside the pipe, is what causes one of the contact pair’s elements to deflect. Water pumping systems make use of these flow sensors. Due to the device’s limited throughput capacity, low-power boiler make-up pumps or water pumps for ballast tanks are fitted.

In a two-circuit boiler, the flow sensor is frequently built as a microswitch on the three-way valve. Water pressure enters the cavity when the tap on the DHW circuit is opened, deforming the diaphragm and moving the stem and microswitch. The boiler is now providing hot water instead of heating.

Boilers with medium capacities use float sensors. The design consists of a letter-shaped housing with connections for the inlet and outlet of water, as well as an internal component that measures flow: a float.

The deflected plate scheme employs a similar measurement principle. In this instance, the float with a magnetic insert suspended on the center pin is impacted by the water flow via the sensor housing. The float sensor rises to the top of the chamber as the flow rate increases, and then the reed switch’s contacts are closed by the insert’s magnetic field.

Certain boiler models—like the ARISTON UNO—have a sensor that is a plastic square housing with a fixed reed switch on the exterior wall and an installed swinging float mechanism inside. It is not connected to the water. The reed switch on the wire closes the contact as soon as the pressure increases the "swing" of the float with the magnet.

These three gadgets are categorized as signaling devices. They require a specific water flow rate to function. The device will sound a signal and stop providing information once the flow reaches the level required for the boiler to operate safely. The contacts will stay open and the pump won’t turn on if it is less than the amount needed for the motor to turn on. The reed switch closes the circuit and the boiler or boiler begins to supply water as soon as the flow rate increases.

A smaller turbine inside a plastic housing rotates in response to water flow in another variation of the water flow sensor. The sensor embedded in the housing experiences a magnetic field perturbation when the wheel’s blades rotate. At the output, there is a pulse signal.

There are two benefits to this plan:

1. The device is able to work in a wide range of water flow rate – within 10-120 liters of liquid.
2. The flow sensor gives an accurate water flow rate, which is important for most gas boilers of two-circuit type.

A circular plastic body with two inlet and outlet connections could be the sensor’s design. Certain boiler models, such as the ARISTON CLASS, have a sensor that resembles a tube cartridge with threads on both ends. An axial turbine is located inside the tube, and a sensor with wiring and a connector is located on the side wall.

Appliance selection criteria

Pumps that fill boilers can be connected to turbine devices in addition to the boiler. Installing a second control board is all that is required to transform the sensor’s pulse signal into an electric motor’s start/stop signal.

The board will turn off the boiler or boilers at specific speeds as the boiler fills, the flow resistance rises, and the turbine rotates more slowly. However, based on the opinions of specialists who maintain individual heating boilers, this is not the ideal choice because the turbine consistently gathers debris. Consequently, in order to blow out or flush the working element with a powerful stream of water, it is required to remove the housing or the cartridge.

A device with a float is easier to clean than one with a small turbine, which is more prone to damage from careless handling, as demonstrated by experience.

Reed flow sensors are a better option if it’s necessary to schedule the pump’s start in addition to the boiler. They can also assist you in connecting an electric boiler to an irrigation pumping group, hot water supply, or heating circuit.

For two-circuit boilers, the installation thread, the sensor’s internal resistance, and the water flow rate are taken into consideration when choosing flow control devices. In addition to water flow rate, operating pressure, mains voltage, relay or reed switch level are also monitored by pump sensors.

Water make-up of a two-circuit gas boiler is another area where flow control devices are used. During the summer, it frequently happens that there is insufficient water pressure in the water supply to open the gas valve. DHW boiler is unresponsive, regardless of how far the tap is opened.

For this reason, the pipe in front of the boiler has a make-up pump fitted with a reed-style sensor. When the boiler unit’s DHW tap is opened, the flow increases and the make-up pump begins to operate, applying pressure to the three-way valve. The booster pump is turned off and the flow decreases when the tap is closed.

Boilers for residential heating frequently use models that are coupled with a temperature or pressure switch. In this instance, the sensor keeps an eye on both the flow rate and the pipe pressure.

For instance, in steam heating, a specific pressure must be maintained while pumping the superheated coolant through the heat exchanger inside a closed circuit. If the flow and pressure don’t reach a certain threshold, the sensor won’t activate the pump. The temperature sensor functions in a similar manner.

Overview of products of the best manufacturers

There are so many models available that it can be challenging to weigh the benefits and drawbacks. Therefore, the most effective designs—which have been used on boilers and pumps for more than a dozen years—should be the basis for selecting an appropriate control device.

Electrolux Basic New AC13040003

Utilized in the "Basic New," "Basic X," and "Basic S" series of Electrolux gas boilers. Brass that resists corrosion is used to make the casing. mounted directly on the pump inlet within the boiler.

A turbine is located inside the brass housing, and a fixed Hall sensor is located on its exterior. Even without any specific filters or unloading cavities, the apparatus is incredibly dependable.

The Hall sensor is the component that is most susceptible. Without taking the device’s body out of the boiler, it can be changed by simply unscrewing the screw.

Viessmann Vitopend WH1D

In the hot water system, a combined device with flow and temperature sensors. From Direct Sensors, Inc. Up to 30 kW boilers under the Viessmann brand have it installed.

It is regarded as one of the most trustworthy. Put together using the reed relay design. The case has no brass components and is composed of shockproof plastic.

Gathers a lot of dirt while in use. It is simple to clean, but first the device needs to be taken out of the boiler. When disassembling, there’s a chance that the plastic latch will get damaged.

Ariston GENUS CLAS B 24

Italian Ariston boiler flow sensor. The body, shaped like a cartridge, is composed of impact-resistant plastic. Operational scheme: turbine coupled with Hall sensor.

There is a compensating slot system in the housing. This makes it possible for dirt and debris to build up on the sump filter’s inner surface rather than the impeller.

The magnetic sensor is enclosed in a plastic casing. The turbine is housed in a separate cage, making device maintenance easier. You will need to replace the device with a new one because it cannot be repaired.

Extremely stable and dependable when operating.

Grundfos UPA 120

Made in Denmark. Suitable for use in water supply systems that pump water from a well, swimming pool, boiler, or well; also suitable for use in floor heating boilers of any kind. The primary goal is to prevent the centrifugal pump motor from operating underload. circuit for relays.

Because the device is housed in an IP67-rated housing, it can be mounted directly on the motor housing and switched on. able to run on motors as large as 2.2 kW. The motor is started by the sensor at a 120 l/h flow rate.

Genyo Lowara Genyo

Made in Poland. Float was in operation. Designed to serve as a pumping station for individual heating boiler make-up systems and home water supply systems. When the minimum flow level is 1.5 l/min, the engine up to 2.2 kW starts.

The device automatically stops pumping water into the system when the boiler’s DHW tap is turned off because it has a sensor inside that controls the liquid pressure at the pump outlet.

Immergas 1.028570

This is a traditional flow sensor circuit that includes a Hall sensor and a turbine. utilized in Immergas brand boilers made in Italy. The housing is made up of a brass fitting and a plastic chamber. The unit is easily disassemblyable into multiple parts for cleaning or repairs by removing the bracket.

The device’s straightforward construction and the ability to disassemble the flow sensor directly on the boiler to eliminate impurities are two of the design’s advantages.

The device is half the price of competitors and is affordable and dependable.

Putting in a water flow sensor can be a wise choice for increased financial savings and energy efficiency in your house. By monitoring water flow through your plumbing system, these devices enable you to keep an eye on usage and possibly spot leaks or inefficiencies. The accuracy of the sensor readings, compatibility with your current plumbing system, and any extra features like wireless connectivity or smartphone integration should all be taken into account when choosing a water flow sensor.

It’s important to choose the ideal location for your water flow sensor before installation. This is usually located near the point where the main water line enters your house. Make sure the sensor can be mounted appropriately and that access to it for upkeep or troubleshooting is not a problem. To guarantee accurate readings, calibrate the sensor after installation in accordance with the manufacturer’s instructions.

To guarantee that your water flow sensor keeps working correctly over time, regular maintenance is essential. Check the sensor for wear or damage on a regular basis, and clean it if needed to avoid accumulation that could compromise its accuracy. Furthermore, keep a regular eye on the sensor readings to spot any abrupt variations in water consumption that might point to a leak or other problem.

In conclusion, installing a water flow sensor in your house can have a number of advantages, including early leak or plumbing problem detection and water conservation and lower utility costs. You can have confidence in your decision to create a more sustainable and energy-efficient home by choosing the appropriate sensor and ensuring its proper installation.

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