Measure your real-time energy and/or water usage in Home Assistant
The WaterP1MeterKit V3 with built-in WiFi, Ethernet and PoE is the most flexible solution to date. Thanks to the detachable water sensor, you can choose whether to read out exclusively your energy meter, exclusively your water meter, or both. Additionally, the V3 offers an extra expansion port to which you can optionally connect a water leak sensor or door sensor. This gives you real-time insight into your consumption and more – fully integrated in Home Assistant.
Discover the WaterP1MeterKit: A meticulously handcrafted Dutch creation, fully developed and designed to meet your needs.
Specifically designed for Home Assistant & ESPHome: The Water Meter Kit is specially designed to seamlessly integrate with Home Assistant & ESPHome.
Maximum flexibility: Measure energy, water, or both
The V3 gives you the choice: use exclusively the detachable water sensor for water consumption, only the P1 connection for energy consumption, or combine both for total insight. The separate water sensor with 3-meter cable offers maximum installation flexibility.
Home Assistant
Full integration
Make your DSMR meter even smarter and more insightful.
Upgrade your smart home with the P1MeterKit. Get a complete digital overview of both your electricity and gas consumption by reading your DSMR meter with our kit. Monitor precisely how much electricity and gas you consume during daily activities, such as running the washing machine, dryer, using lighting, the heat pump, and more.
Home Assistant
Full integration
DSMR Reader
Compatible
Installation examples — Easy to mount in under 1 minute
Below you'll find 3 example installation videos for popular water meter types. Our universal holder works with many more brands — see the compatible water meters list below for a complete overview.
Compatible water meters
Our universal holder fits most European analog water meters. Below you’ll find the most common types per brand.
Different water meter brand?
Our sensor detects the metal rotating disc in analog water meters. This small metal disc (often silver-colored) rotates when water flows through. The sensor registers each rotation via magnetic detection = 1 liter of water. ⚠️ No rotating metal part? Then our sensor won't work.
Not sure if your water meter is compatible? Send us a photo!
Compatible energy meters
Compatible with DSMR 2.x, 3, 4 or 5 energy meters with a P1 port. Check if your meter has a P1 (RJ12) — with P1 you’re good.
What’s in the V3 box?
- WaterP1MeterKit V3 main unit with WiFi, Ethernet and PoE support
- Separate water sensor with 3‑meter cable
- Universal holder for water meter (fits most European meters)
- RJ12 cable (2 m) for DSMR energy meter
- Quick Start Guide with installation instructions
Optional accessories
- USB‑C cable (3 m) & Power Adapter: EU or Universal (US/AU/UK)
- Water leak sensor or door sensor for the expansion port
V3 advantages
- Flexible setup: separate 3‑meter water sensor — place exactly where needed
- Measure energy, water or both simultaneously
- Switch between WiFi and Ethernet in software; PoE supported
V3: Even more possibilities and flexibility in Home Assistant
The WaterP1MeterKit V3 introduces groundbreaking flexibility for your smart home setup. Unlike previous versions, you can now choose exactly what you need: install only the energy meter function, use exclusively the water meter function, or combine both for complete insight. The 3-meter cable of the detachable water sensor enables installation in the most challenging situations - even when your water meter and meter cabinet are far apart. Additionally, the V3 is the first to offer an expansion port for an extra sensor like water leak detection or a door contact, elevating your monitoring system to the next level.
Energy Dashboard
Full integration with the Home Assistant Energy Dashboard for real-time insights.
Modular & Flexible
Choose exactly what you need: energy only, water only, or both combined.
Expansion Port
Add extra sensors like a water leak sensor or door contact.
"The V3 is a game-changer! The detachable water sensor gave me the flexibility to monitor only my water meter without hassle with the P1 port. Later I could easily expand to energy monitoring. The optional water leak sensor has already saved me once from water damage. This modular approach is brilliant – exactly what I needed for my setup!"
Happy customer
Ready in 3 steps — under 2 minutes
Mount holder, connect power/network and link to Home Assistant.
Place the universal holder
Click the universal holder onto your water meter. Fits most European analog meters.
Connect: USB‑C (realtime) or Ethernet with PoE
Choose your power/connection and start measuring instantly.
- USB‑C (Realtime): live data for dashboards/automations (API/MQTT).
- Ethernet with PoE: one cable for power + data, ultra‑stable and 100% local.
Add to Home Assistant
Open Home Assistant → Settings → Devices & Services → Integrations.
- ESPHome: WaterP1MeterKit usually appears automatically. Click Configure and follow the steps.
- Energy Dashboard: Settings → Dashboards → Energy; select water and DSMR (P1) entities from the kit.
Open Source and 100% Local with ESPHome
Our firmware is built on ESPHome. The entire configuration is transparent and adjustable. Everything runs locally without cloud dependency. Integrate directly into Home Assistant and manage updates yourself.
Fully Open Source
All source code is available on GitHub. Customize the firmware to your needs.
Built on ESPHome
Runs on ESPHome, the most popular open-source IoT platform. OTA updates, no cloud needed.
100% Local & Private
All data stays within your own network. No cloud, no subscription, no data collection.
Open standards: REST API & MQTT (TLS)
For advanced users: 100% freedom
Connect with your own systems and keep control over your data. Thanks to TLS encryption and fully local integrations, privacy is standard. Use REST for HTTP integrations or choose MQTT (with username/password and optional TLS) for maximum compatibility with other platforms.
Works out‑of‑the‑box for everyone. For makers & power users everything is open and extensible: scriptable, automatable and integrable with your favorite tools.
ESPHome without Home Assistant
- Use an MQTT broker (e.g., Mosquitto). Process topics in your own apps or automations.
- Integrate with Node‑RED, OpenHAB, Homey or Domoticz via MQTT nodes/adapters.
- Write data to InfluxDB (via Telegraf or Node‑RED) and visualize in Grafana.
- The ESPHome native API is optional; universal coupling works with
mqtt:in the device config.
MQTT
Subscribe to all topics:
mosquitto_sub -h broker.local -p 8883 -u <user> -P <pass> \
--cafile /path/ca.crt -t 'waterp1meterkit/#' -v
Publish a test message:
mosquitto_pub -h broker.local -p 8883 -u <user> -P <pass> \
--cafile /path/ca.crt -t 'waterp1meterkit/cmd/restart' -m '1'
ESPHome base config (MQTT):
mqtt:
broker: broker.local
username: !secret mqtt_user
password: !secret mqtt_pass
topic_prefix: waterp1meterkit
discovery: false
# For TLS use the secure broker port (e.g., 8883) and certificates as per ESPHome mqtt docs.
REST / HTTP
Read current values (GET):
curl -s https://waterp1meterkit.local/api/metrics \
-H 'Authorization: Bearer <token>'
Trigger an action (POST):
curl -X POST https://waterp1meterkit.local/api/actions/restart \
-H 'Authorization: Bearer <token>'
ESPHome http_request to your own endpoint:
# Requires a sensor with id: current_liters defined elsewhere
http_request:
verify_ssl: true
button:
- platform: template
name: "Send webhook"
on_press:
- http_request.post:
url: https://nodered.local/webhook/waterp1meterkit
headers:
Content-Type: application/json
Authorization: Bearer <token>
json:
device: waterp1meterkit
liters: !lambda "return id(current_liters).state;"
Why WaterP1MeterKit V3?
What customers say
Real experiences with WaterP1MeterKit
"The WaterP1MeterKit has completely changed my view on energy management. It was a breeze to install and integrate directly with my Home Assistant system. Now I can monitor my water and electricity consumption in real time. The Energy Dashboard in Home Assistant is ideal."
"I am truly impressed by the WaterP1MeterKit! It has completely changed my approach to managing energy and water consumption. Now I can keep an eye on everything and adjust as needed. A smart addition to our home!"
"The installation of the WaterP1MeterKit was surprisingly simple and the integration with Home Assistant works flawlessly. It's fantastic to monitor both my energy and water consumption from a single app. Truly a gamechanger!"
"Since I started using the WaterP1MeterKit, I have become much more aware of my consumption. It helps us live more sustainably and save on our bills. Moreover, the Ethernet and PoE support are extremely handy!"
"I was looking for a way to better monitor my usage and came across the WaterP1MeterKit. What a fantastic device! The data it delivers is very accurate, and it displays both water and energy consumption in an excellent way."
"The WaterP1MeterKit is incredible! I love how easy it is to set up and the data is always accurate."
Frequently Asked Questions
The WaterP1MeterKit V3 is our most flexible solution to date. Thanks to the detachable water sensor you can choose to read only your energy meter, only your water meter, or both. The V3 supports WiFi, Ethernet with PoE and offers an extra expansion port for a water leak sensor or door sensor. You can switch between WiFi and Ethernet firmware at any time without hardware changes.
Absolutely! The V3 provides real‑time insight into both your water and energy consumption. Uniquely, you can choose: use only the detachable water sensor for water, only the P1 connection for energy, or combine both for a complete picture. Everything appears in Home Assistant in real time.
The WaterP1MeterKit is designed to fit most common analog water meters and smart meters. For a full list of compatible meters, please check our website.
The V3 offers maximum flexibility: mount the detachable water sensor (if desired) with the 3‑meter cable to your water meter using the universal holder. Optionally connect the RJ12 cable to your energy meter’s P1 port. Connect the V3 via WiFi, Ethernet or PoE. Home Assistant will usually detect the device automatically. You can also choose to use only the water sensor or only the P1 connection.
The detachable water sensor with a 3‑meter cable provides installation freedom: place the sensor exactly where needed, even when your water meter and meter cabinet are far apart. You can also choose to use only the water sensor without the P1 connection.
Yes. The V3 offers unique firmware flexibility. You can switch between WiFi and Ethernet at any time without hardware changes. Start with WiFi and later move to a stable Ethernet connection with PoE — or the other way around — depending on your situation.
The V3 brings important improvements: the water sensor is now detachable with a 3‑meter cable for maximum installation freedom. You can choose to measure energy only, water only, or both. The V3 adds an extra expansion port for a water leak sensor or a door sensor. Firmware can be switched between WiFi and Ethernet without hardware changes. PoE support provides stable power and data over a single cable. This makes the V3 the most modular and flexible solution to date.
Yes. Together with Home Assistant you can set up notifications for specific peaks or other parameters.
No. After purchasing the kit there are no monthly fees. You only need a working Home Assistant installation.
Your privacy is essential to us. Data is only sent and stored within your own network unless you choose to share it with external services. We do not use any cloud connection.
The V3 is compatible with most analog water meters from brands such as Actaris, Elster, Honeywell, Itron and Sensus. For energy meters, the V3 supports all DSMR 5.0 smart meters with a P1 port from suppliers such as Landis+Gyr, Kamstrup, Sagemcom and Kaifa. Visit waterp1meterkit.nl for a complete overview with photos and model names of all compatible water and energy meters.
Yes. The V3 has a dedicated expansion port to which you can optionally connect a water leak sensor or a door sensor (sold separately). You can use one of these sensors at a time. The sensor is integrated directly into Home Assistant alongside your energy and water data.
The V3 supports two power options: USB‑C or PoE (Power over Ethernet). USB‑C is the traditional method with a separate power cable and adapter. PoE is convenient because it supplies both data and power via a single network cable — no separate power cable required. Note: PoE is only provided by dedicated PoE switches or PoE injectors. Not every network switch has PoE. If you don’t have a PoE switch, use a PoE injector or choose the USB‑C power option.
Still have questions?
Get in touch with us
Technical Specifications
Connection to Water and Energy meter
- Water meter: Direct connection with a universal holder for mounting the water sensor on the 1-liter metal indicator of the water meter.
- Energy meter: RJ12 port for direct connection to DSMR compatible energy meters.
Network connection
- Wi-Fi IEEE 802.11 b/g/n (2.4 GHz), supports WPA/WPA2 security.
- Ethernet connection with support for Power over Ethernet (PoE) for a direct and stable network connection.
Data transfer
- Water consumption update interval: Every 1 liter.
- Energy consumption update interval: Every second for real-time insight.
Physical Dimensions of the Kit
92 x 47.5 x 26.5 mm
Cable length
- RJ12 cable for energy meter: 2 meters.
- USB-C cable for power: 3 meters.
- Sensor-to-kit cable for water meter: 3 meters (not removable).
Power supply
- USB-C port for power supply (5V, 1A) with included USB adapter (if chosen).
- Alternative power supply possible via PoE for an integrated solution without additional power cables.
Operational Classification
IP20 (suitable for indoor use).
Temperature range
Operational from -10 °C to +40 °C.
Compatibility
Compatible with DSMR versions 4.0 and 5.0 for energy meters and with all common water meters as indicated on our website; if in doubt, contact us.
Software
Fully integrated with Home Assistant, support for firmware updates (OTA) for continuously improved functionality.
Inclusive
- Universal holder with screws for easy installation on the water meter.
- Quick Start Guide