Measure every water point on its own.
Up to four flow sensors on one kit. For every shower, tap, pipe or heating circuit you see litres and flow, and with the right sensor the water temperature too. Locally in Home Assistant, in our app, or both.
What do you want to measure?
Four ports, four places of your choice. This is what customers use the WaterFlowKit for, and how to set it up.
Shower and bathroom
Put a sensor on the hot pipe to the shower, and one on the cold if you like. You see how many litres each shower takes, how long it lasts and how hot the water comes out of the boiler.
- Sensor
- G1/2" or G3/4" with temperature (brass)
- You see
- Flow, litres per shower and the temperature of the hot water
- Smart idea
- Make the bathroom light blink after eight minutes in the shower.
Shower 07:05 · 8 min · 54 L hot water · 52.0 °C
I can finally see how much hot water the shower uses. Very handy for being more conscious about it. Recommended!
Kitchen, toilet and appliances
Measure the kitchen tap, the washing machine, the dishwasher or the toilet separately. You see what each appliance uses per day or per run, and whether the toilet keeps running.
- Sensor
- G1/2" (DN15), brass or stainless steel, with or without temperature
- You see
- Litres per day, per wash or per flush
- Smart idea
- Get an alert when the toilet keeps running for more than ten minutes.
Washing machine · 52 L per wash
I use the WaterFlowKit to monitor the water consumption of my toilet how many liters it uses and it works perfect.
Pipes and leaks
On the main pipe or a branch you see when water keeps flowing while nobody uses any, like a running toilet or a burst pipe. With a motorised valve, Home Assistant shuts off the supply itself. A flow sensor responds from about 1 litre per minute, so it won’t catch drips.
- Sensor
- G3/4" (DN20) or G1" (DN25) on the main pipe
- You see
- The flow per pipe, also at night and while you’re away
- Smart idea
- Close the main valve when water flows for more than thirty minutes at night.
02:14 · 3.2 L/min for 31 minutes · main valve closed
Heat pump and central heating
Two sensors with temperature, one on the supply and one on the return, measure the flow and the temperature difference. Home Assistant uses that to work out how much heat your heat pump delivers, and with a power meter, its COP.
- Sensor
- 2× G3/4" (DN20) with temperature, up to 30 L/min
- You see
- Flow, supply and return temperature, and the thermal power in kW
- Smart idea
- Get an alert when the COP stays below 2.5 for two hours.
12.0 L/min · ΔT 5.0 °C · 4.18 kW · COP 4.2
I use the kit to monitor my heat pump. The data is stable and reliable, exactly what I was looking for.
Garden, pool and aquarium
Measure how much water a sprinkler run takes, or watch the pump of your pool or aquarium: if the flow drops away, the pump has stopped or the filter is full. For large pipes there are stainless steel sensors up to G2".
- Sensor
- Garden: G1/2" or G3/4" indoors on the pipe to the outside tap. Pool: G1½" or G2" in stainless steel
- You see
- Litres per sprinkler run and the flow of the pump
- Smart idea
- Get an alert when the flow of the filter pump drops away.
Sprinkling 20:00 to 20:25 · 312 L
Beer tap and business
A stainless steel sensor in the beer line counts how much has been poured, per keg or per tap. One is already running on a beer keg setup. With several kits you also measure each apartment, pitch or commercial kitchen separately.
- Sensor
- G1/2" (DN15) in stainless steel, the choice for drinking water and beverages
- You see
- Litres per tap, per keg or per unit
- Smart idea
- Get an alert when the keg is almost empty.
Tap 1 · 50 L keg · 38.6 L poured
Which sensor fits your pipe?
You choose a sensor per port, in five sizes from G1/2" to G2". Every sensor has a 1 metre cable with plugs on both ends, so it simply plugs into the kit.
- Brass or stainless steel
- Brass is sturdy and affordable, for most uses. Stainless steel is food safe and hygienic: the choice for drinking water and beverages.
- With or without temperature
- The G1/2" and G3/4" sensors also come with a temperature sensor (brass). It measures the water temperature up to 80 °C, to within ±0.5 °C.
- Fitted in the pipe
- The sensor goes into the pipe, with the arrow in the direction of flow. Not doing it yourself? Have an installer fit it watertight.
| Sensor | Flow | Temperature | Material | Price |
|---|---|---|---|---|
| G1/2"DN15 · pipe approx. 15 mm | ||||
| YF-B1 | 1–25 L/min±3% | No | Brass or stainless steel | From €11.00 incl. 21% VAT |
| YF-B7 | 1–25 L/min±3% | Yes, up to 80 °C | Brass | €12.00 incl. 21% VAT |
| G3/4"DN20 · pipe approx. 20 mm | ||||
| YF-B5 | 1–30 L/min±3% | No | Brass or stainless steel | From €12.00 incl. 21% VAT |
| YF-B6 | 1–30 L/min±3% | Yes, up to 80 °C | Brass | €13.00 incl. 21% VAT |
| G1"DN25 · pipe approx. 25 mm | ||||
| YF-B10 | 1–50 L/min±5% | No | Brass or stainless steel | From €14.00 incl. 21% VAT |
| G1½"DN40 · pipe approx. 40 mm | ||||
| YF-DN40-S | 5–150 L/min±3% | No | Stainless steel | €44.00 incl. 21% VAT |
| G2"DN50 · pipe approx. 50 mm | ||||
| YF-DN50-S | 10–200 L/min±3% | No | Stainless steel | €47.00 incl. 21% VAT |
The pipe size in millimetres is a guide; the wall thickness of the pipe can make it differ. Prices include VAT and the 1 metre cable.
What does your heat pump really deliver?
Two sensors with temperature on the supply and return measure the flow and the temperature difference. With that, Home Assistant works out how much heat your heat pump delivers, and with a power meter, how efficiently it does so.
- Flow, supply and return temperature live in Home Assistant
- Thermal power: flow × temperature difference × 0.0697 = kW
- COP: the thermal power divided by the electricity your heat pump uses, measured with a separate power meter
- Two G3/4" sensors with temperature measure up to 30 L/min: at a 5 °C difference that is over 10 kW
At the moment I use the WaterFlowKit to calculate the coefficient efficiency of my heat pump.
Heat pump calculator
Slide to the values the WaterFlowKit measures, and to the power your heat pump draws from the socket.
- Temperature difference
- 5.0 °C
- Thermal power
- 4.18 kW
- COP
- 4.2
12.0 L/min × 5.0 °C × 0.0697 = 4.18 kW
The calculator assumes water in the circuit. With glycol the factor is lower. The kit and the app don’t calculate this themselves; in Home Assistant you do it with a template sensor, see the example further down.
No Home Assistant? Every sensor in the app
With the cloud firmware, the WaterFlowKit sends its readings to the free SmartHomeShop app. Give every sensor its own name and colour, and see per pipe what’s flowing now and what you use today, this month and this year.
Sample data
- Total flow
- 4.5 L/min
- Active sensors
- 1 / 4
- Water temperature
- 37.5 °C
- Average of 2 sensors
- Ambient
- 19.4 °C
- WaterFlowKit sensor
- Humidity
- 58%
Today
Total
This month
Total
This year
Total
Live Graphs
Last 3 hours
Water usage
4.5 L/min
Last 3 hours per minute · one line per sensor
Connection status
Uptime 99.8%
Sample data
Trends
30 days- Kitchen hot
- 1,925.1 L
- Kitchen cold
- 1,283.9 L
- Shower hot
- 4,789.8 L
- Shower cold
- 1,550.7 L
- Total
- 9,549.6 L
Sensor distribution
9,549.6 LTotal
Sensor details
- Kitchen hot1,925.1 L20.2%
- Kitchen cold1,283.9 L13.4%
- Shower hot4,789.8 L50.2%
- Shower cold1,550.7 L16.2%
Usage by day of week
Water temperature per hour of the day
Sample data
Alerts
-
Possible water leakHigh water flow
> 10 L/min
Last triggered: 5 days ago
-
Frost alarmLow temperature
< 3 °C
Not triggered yet
Recent activity
Possible water leak: 12.4 L/min (> 10.0 L/min)
What the email looks like
SmartHomeShop.ioPossible water leak - Utility room
Possible water leak
An alert was triggered on your device Utility room.
Measured value: 12.4 L/min
Threshold: > 10.0 L/min
Quick presets
- Possible water leak> 10 L/min
- Frost alarm< 3 °C
- Heat alarm> 35 °C
- Device offline> 5 min
Send via
- Push notifications
Sample data
Flow sensor settings
Number of sensors 4
-
Flow sensor 1
- Name / Alias
- Kitchen hot
- Colour
- #f97316
- Sensor type
- YF-B1 / YF-B7 (660 pulses/L)
- Calibration
- 100%
-
Flow sensor 2
- Name / Alias
- Kitchen cold
- Colour
- #3b82f6
- Sensor type
- YF-B1 / YF-B7 (660 pulses/L)
- Calibration
- 100%
-
Flow sensor 3
- Name / Alias
- Shower hot
- Colour
- #ef4444
- Sensor type
- YF-B1 / YF-B7 (660 pulses/L)
- Calibration
- 100%
-
Flow sensor 4
- Name / Alias
- Shower cold
- Colour
- #06b6d4
- Sensor type
- YF-B1 / YF-B7 (660 pulses/L)
- Calibration
- 100%
Calibrate flow sensor
Catch exactly 1 to 5 litres in a measuring jug or bucket. The app compares it with what the sensor counted and adjusts the correction.
Amount caught
- Every sensor its own name and colour, like Shower hot
- Flow, litres and water temperature per sensor
- Charts from the last hour to a whole year
- An email and push notification on high flow or high daily use
- Calibrate with a bucket test, right in the app
- How your use splits over the sensors, in litres and percent
- Use per day of the week, per sensor
- Average water temperature per hour of the day
- Pick a week, 30 days, a month, this year or your own dates
- Email and push notification when a sensor passes more than 10 L/min, adjustable
- An alert on high daily use over all sensors together, 0.5 m³ by default
- Frost or heat alarm on the room temperature
- An alert when the kit is offline for more than 5 minutes
- Free: 1 alert per device. Plus gives you 20, Pro unlimited.
- Choose how many sensors you use, up to four
- A name and one of eight colours per sensor
- Pick the sensor type, the app uses the right pulses per litre
- Calibrate with a 1 to 5 litre measuring jug, or by hand between 50 and 150 percent
Home Assistant, our app or both
Use WaterFlowKit with Home Assistant, the SmartHomeShop cloud app or both at the same time. With compatible firmware, you can combine local dashboards and automations with remote access to your readings in our app.
Locally with Home Assistant
With local ESPHome firmware, readings go straight to Home Assistant. No SmartHomeShop account or cloud subscription is required.
- Flow and consumption per connected pipe, plus water temperature with a suitable sensor.
- Build dashboards and alerts for prolonged or unusual flow.
Through the SmartHomeShop app
No Home Assistant needed. Open our cloud app in a browser on your phone, tablet or computer, even when you are away from home.
- View flow rates and consumption per connected flow sensor.
- Compare water use and spot patterns in your history.
- Set email and push alerts for supported flow readings.
Cloud use requires an account, internet and cloud firmware that supports your model. Readings and features depend on hardware and firmware; history and usage limits depend on your app plan. With supported firmware, you can also use the app and Home Assistant together.
Find the right firmware
One small box, everything on board
Built by hand in the Netherlands and small enough for the utility room or meter cupboard: 92 × 47.5 × 26.5 mm. Four ports for sensors, and you choose how it connects.
- Four sensor ports
- Per sensor a 3-pin plug for the flow and, on a sensor with temperature, a 2-pin plug. Plug and play, with a 1 metre cable.
- WiFi or Ethernet
- WiFi on 2.4 GHz by default. Prefer a cable? Install the Ethernet firmware, no extra hardware needed.
- USB-C or PoE
- Power via USB-C (5 V, 1 A) or over the network cable with PoE and the Ethernet firmware.
- Also over Thread
- With the Thread firmware it works without WiFi, locally with Home Assistant through your Thread border router.
- Climate in the room
- A built-in sensor also measures the temperature and humidity where the kit is mounted.
- ESPHome firmware
- Install updates or another firmware from Home Assistant, or with the web flasher over USB-C.
Which water kit do you need?
All three work with Home Assistant and our app. Pick what you want to measure.
-
WaterMeterKit
Water use of your whole home, via your water meter
€55.00 incl. 21% VAT
View the WaterMeterKit -
WaterP1MeterKit
Water plus electricity and gas, with WiFi or Ethernet and PoE
€70.00 incl. 21% VAT
View the WaterP1MeterKit -
WaterFlowKit
This pagePer tap, pipe or heating circuit, with up to 4 flow sensors
€58.00 incl. 21% VAT
Buy the WaterFlowKit
What’s in the box?
- WaterFlowKit main unit
- The sensors you choose per port, each with a 1 metre cable
- Quick start guide
Optional
- USB-C adapter set (5 V, 1 A) with a 3 metre cable. Powering the kit over PoE? Then you don’t need it.
How to connect it
Fitting a sensor into a pipe is plumbing: do it yourself or have it done. After that, the kit is connected in no time.
Choose a sensor per point
Mind the pipe size and the flow, and choose brass or stainless steel, with or without temperature. Not sure? Ask us.
Fit the sensor in the pipe
Turn off the water, fit the sensor into the pipe with the arrow in the direction of flow and seal the thread with PTFE tape. Check for leaks when you turn the water back on, and again after 24 hours.
Plug in the cables and connect
Plug the cables into the ports, power the kit via USB-C or PoE and connect it to your network. Home Assistant finds it by itself; for the app you install the cloud firmware.
Everything in Home Assistant
Through ESPHome every sensor arrives with its flow, its total use and, for a sensor with temperature, the water temperature. Build dashboards, alerts and calculations such as the output of your heat pump.
- Per sensor the flow (L/min), the total (L) and the water temperature (°C), every 5 seconds
- The total per sensor in the Energy dashboard
- Set the sensor type and calibration per port from Home Assistant
- Local: the standard firmware sends no readings out of your network
# Heat pump: flow and ΔT from two sensors with temperature
template:
- sensor:
- name: Heat pump thermal power
unit_of_measurement: kW
device_class: power
state: >
{% set kit = 'sensor.waterflowkit_a1b2c3_' %}
{% set flow = states(kit ~ 'flow1_current_water_usage')|float(0) %}
{% set t_in = states(kit ~ 'flow1_water_temperature')|float(0) %}
{% set t_out = states(kit ~ 'flow2_water_temperature')|float(0) %}
{{ (flow * (t_in - t_out) * 0.0697)|round(2) }}ESPHome firmware, public on GitHub
The WaterFlowKit firmware is public on GitHub. See how it works, adapt it in ESPHome or build on it yourself.
- Built on ESPHome
- Updates via Home Assistant or the web flasher, and your own changes in the ESPHome Device Builder.
- One kit, several firmwares
- WiFi or Ethernet, local or with the app, plus a separate Thread firmware. Switching needs no other hardware.
- Local where it can be
- With local firmware, your readings stay within your own network, with no mandatory cloud or subscription.
# WaterFlowKit, ESPHome package
substitutions:
name: waterflowkit-a1b2c3
friendly_name: WaterFlowKit a1b2c3
packages:
smarthomeshop.waterflowkit:
url: https://github.com/smarthomeshop/waterflowkit
ref: main
files: [waterflowkit-v2/waterflowkit-wifi.yaml]
esphome:
name: ${name}
name_add_mac_suffix: false
friendly_name: ${friendly_name}
api:
wifi:Customer Reviews
4,9
Based on reviews
Product rating distribution
- star reviews
4.8 on Google · General business rating
Share your thoughts
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Translated from Dutch Original (Dutch)
Frequently Asked Questions
Answers to the questions we get most about the WaterFlowKit.
-
The WaterFlowKit is designed for easy installation. You can attach it to the water line of your choice, such as the kitchen or bathroom faucet. Attach the provided flow sensors to the pipeline and connect the kit to your Home Assistant system.
-
Yes, the WaterFlowKit supports up to four flow sensors. This allows you to monitor water usage at multiple measuring points in your home, for example hot and cold water or different floors.
-
You need suitable flow sensors, power and a network connection. Choose Home Assistant for local dashboards and automations, or our SmartHomeShop app with supported cloud firmware, an account and internet. Ethernet and PoE require matching firmware; PoE needs a PoE switch or injector.
-
The WaterFlowKit not only measures water consumption in liters per minute, but also the water temperature as it flows through compatible sensors. The main unit also measures the temperature and humidity of the room where the kit is located.
-
The WaterFlowKit supports WiFi, Ethernet and PoE, plus Thread with the Thread firmware. Over Thread it talks to Home Assistant locally through your Thread border router, without WiFi or a cable. For the SmartHomeShop app, choose the WiFi or Ethernet firmware.
-
You get a 2-year warranty on the WaterFlowKit and on the separate flow sensors. Keep your proof of purchase and report a fault through our support portal, and we will find a suitable solution together.
-
Yes, with the WaterFlowKit you can set up notifications in Home Assistant based on custom water consumption thresholds, allowing you, for example, to receive alerts when unusually large amounts of water are consumed.
-
Yes, you can view and analyze historical data of your water consumption over days, weeks, months, and years in Home Assistant, providing insight into your water consumption patterns.
-
Yes, the WaterFlowKit is suitable for both cold and hot water lines and can measure the water temperature as it flows through the sensors.
-
The WaterFlowKit is designed for indoor use and is not recommended for outdoor use where it could be exposed to extreme weather conditions.
-
No. Like Zigbee, Thread uses the 2.4 GHz band, but it is a different protocol. You don't pair the WaterFlowKit as a Zigbee device; it connects through your Thread border router.
-
Yes. With the Thread firmware you need neither WiFi nor a cable: the kit talks to Home Assistant locally through your Thread border router. You need a Thread border router (for example Home Assistant with a Connect ZBT-1 or SkyConnect) and the ESPHome Device Builder; the first installation happens over USB-C. If you want to use the SmartHomeShop app, choose the WiFi or Ethernet firmware.
Still have questions? Get in touch with us
Contact UsTechnical Specifications
- Flow Sensors
- Connect up to 4 flow sensors in 5 pipe sizes, available in Brass and Stainless Steel:
G1/2" (DN15): 1–25 L/min, ±3% accuracy
G3/4" (DN20): 1–30 L/min, ±3% accuracy
G1" (DN25): 1–50 L/min, ±5% accuracy
G1½" (DN40): 5–150 L/min, ±3% accuracy
G2" (DN50): 10–200 L/min, ±3% accuracy
Temperature measurement available on G1/2" and G3/4" models (0 to +80 °C). - Temperature Measurement
- Water temperature: 0 °C to +80 °C with ±0.5 °C accuracy (on compatible sensors).
Ambient temperature and humidity monitoring via built-in sensor. - Network Connection
- Wi-Fi IEEE 802.11 b/g/n (2.4 GHz), supports WPA2/WPA3 security.
Ethernet (RJ45) with Power over Ethernet (PoE) support for a stable wired connection.
Thread via the built-in IEEE 802.15.4 radio, with the Thread firmware and a Thread border router. - Dimensions
- 92 x 47.5 x 26.5 mm (main unit)
- Cable Length
- USB-C power cable: 3 meters
Sensor cable: 1 meter per sensor (detachable connectors on both ends) - Power Supply
- USB-C port for power supply (5V, 1A) with included adapter (if chosen).
Power over Ethernet (PoE) for combined data and power via a single cable. - Protection Rating
- IP52 for sensors (protection against dust and light moisture).
IP20 for the main unit (suitable for indoor use). - Operating Temperature
- -10 °C to +40 °C for the main unit.
- Software
- Fully integrated with Home Assistant via ESPHome.
Home Assistant Energy Dashboard compatible.
Over-the-air (OTA) firmware updates.
With the Thread firmware it also works over Thread; you install it with the ESPHome Device Builder. - In the Box
- WaterFlowKit main unit
Selected flow sensors (with temperature measurement if chosen)
USB-C power adapter and cable (if chosen)
Quick start guide
Start with one sensor, grow to four.
Order the kit and choose the sensor that fits your pipe for each port. Want to measure more later? An extra sensor plugs straight into a free port.
€58.00 incl. 21% VAT
In stock
Back-order
Out of stock
You choose the sensors per port when you order.
2-year warranty