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WaterP1MeterKit V4

Measure your real-time energy and/or water usage in Home Assistant

The WaterP1MeterKit V4 with built-in WiFi, Ethernet and PoE is our newest and most flexible solution. Thanks to the detachable water sensor, you can read only your energy meter, only your water meter, or both at the same time. The V4 also includes an extra expansion port and is prepared for Thread/OpenThread for users with a suitable Thread network.

Requires Home Assistant
Thread/OpenThread ready
Does not work standalone
Buy now
WaterP1MeterKit

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.

WATER MONITORING

Maximum flexibility: Measure energy, water, or both

The V4 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.

Shower
Toilet
Washing Machine
Dishwasher
Faucet
Bath
Garden Irrigation
Boiler
Swimming Pool
Kitchen Faucet
Bathroom Faucet
Garden Hose

Home Assistant

Full integration

ENERGY MONITORING

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.

Washing Machine
Dryer
Lighting
Heat Pump
Cooktop
Electric Kettle
Bike Charger
Electric Heating Boiler
Aquarium
Electric Car
Computer
Fan

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.

Type 1, Itron / Actaris / Schlumberger
Type 2, Sensus
Type 3, Elster / Honeywell

Compatible water meters

Our universal holder fits most European analog water meters. Below you’ll find the most common types per brand.

Not sure if your water meter is compatible?
Send us a photo or chat live (7 days/week) on Discord.
sensus620.png
Sensus
itron.png
Itron
elster.png
Elster Kiwa
itron.png
Schlumberger
honeywell.png
Honeywell
itron.png
Actaris
diehl.png
Diehl
zenner.png
Zenner ETDK ZR
zenner2-1760090131.png
Zenner ETWD
zenner3.png
Zenner ZR
dh-metering.png
DH Metering
elster2.png
Elster
hidroconta.png
Hidroconta
maddalena.png
Maddalena Plus C
madalena-mvm.png
Maddalena MVM

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.

Questions about your P1/DSMR smart meter?
Send us a photo or chat live (7 days/week) on Discord.
IN THE BOX
WaterP1MeterKit V4 - In the box

What’s in the V4 box?

  • WaterP1MeterKit V4 main unit with WiFi, Ethernet and PoE support
  • Prepared for Thread/OpenThread with matching firmware and a Thread border router
  • 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

V4 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
  • Prepared for Thread/OpenThread for modern Thread networks
Home Assistant

V4: Even more possibilities and flexibility in Home Assistant

The WaterP1MeterKit V4 builds on the previous generation and adds modern hardware prepared for Thread/OpenThread. You still choose exactly what you need: energy only, water only, or both at the same time. The 3-meter detachable water sensor cable enables installation in challenging situations, even when your water meter and meter cabinet are far apart. The expansion port can optionally be used for a water leak sensor or door contact.

Home Assistant App
Energy
1.24 kWh
Water
12.3 L/min
Gas
0.42 m³

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 V4 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!"
Quote author Happy customer
INSTALLATION

Ready in 3 steps, under 2 minutes

Mount holder, connect power/network and link to Home Assistant.

1

Place the universal holder

Click the universal holder onto your water meter. Fits most European analog meters.

2

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.
3

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.
You can also connect WaterP1MeterKit to DSMR Reader (stand‑alone Docker app; independent from Home Assistant).
Open Source

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.

View on GitHub
smarthomeshop/waterp1meterkit
waterp1meterkit.yaml
# WaterP1MeterKit ESPHome Configuration (packages)
substitutions:
name: waterp1meterkit-587c20
friendly_name: WaterP1MeterKit 587c20
packages:
smarthomeshop.waterp1meterkit: github://smarthomeshop/waterp1meterkit/waterp1meterkit-v4/waterp1meterkit-wifi.yaml@main
esphome:
name: ${name}
friendly_name: ${friendly_name}
api: # encryption key lokaal instellen
wifi: # ssid/password via secrets
Open Source
ESPHome
100%
Open Source
0%
Cloud
OTA
Wireless Updates
Thread
Prepared
OPEN STANDARDS

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.
Tip: use broker port 8883 for TLS and create per‑device credentials/certificates.

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;"
COMPARISON

Why WaterP1MeterKit V4?

Feature
WaterP1MeterKit V4
Other solutions
Wi‑Fi, Ethernet, PoE & Thread/OpenThread prepared
Often Wi‑Fi only, no Ethernet/PoE or Thread preparation
Real‑time measurement
Not always real‑time / external cloud
Open Source & ESPHome
Closed firmware or cloud dependent
Universal (optionally transparent) holder
Limited or brand‑specific holders
Integrations: Home Assistant, MQTT, InfluxDB, Grafana
Limited or paid integrations
100% local, no cloud, no monthly fees
Often cloud or account required
Measure water, P1 energy or both simultaneously (one device)
Need two separate products to measure both
Expansion port: optional water‑leak or door sensor
No expansion port / not supported
Reviews

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."

""

Translated from Dutch Original (Dutch)

Bart V.
Bart V.
Verified buyer

"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!"

""

Translated from Dutch Original (Dutch)

Jasper
Jasper
Verified buyer

"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!"

""

Translated from Dutch Original (Dutch)

K.
K.
Verified buyer

"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!"

""

Translated from Dutch Original (Dutch)

Thomas
Thomas
Verified buyer

"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."

""

Translated from Dutch Original (Dutch)

Dion
Dion
Verified buyer

"The WaterP1MeterKit is incredible! I love how easy it is to set up and the data is always accurate."

""

Translated from Dutch Original (Dutch)

Alex
Alex
Verified buyer
5.0
Average rating from verified buyers
Frequently Asked Questions

Frequently Asked Questions

The WaterP1MeterKit V4 combines water and energy monitoring in one device. You can read only your smart meter, only your water meter, or both at the same time. The V4 supports WiFi, Ethernet and PoE, has a detachable water sensor with a 3-meter cable and includes an extra expansion port for a water leak sensor or door sensor.

In daily use the V4 works like the V3, but it uses updated hardware that is also prepared for Thread/OpenThread. For normal use, WiFi, Ethernet and PoE remain the most practical options. The detachable water sensor, P1 connection and extra expansion port are still included.

Yes. The V4 shows your water and energy usage in real time in Home Assistant. You can choose to use only the P1 connection, only the water sensor, or combine both for a complete overview.

The V4 is designed for DSMR smart meters with a P1 port and most common analog water meters in the Netherlands and Belgium. If you are not sure, check the compatibility list or contact us with a photo of your water meter.

No. Thread uses the same 2.4 GHz radio technology as Zigbee, but it is a different protocol. You do not pair the WaterP1MeterKit V4 as a Zigbee device. For most customers we recommend WiFi or Ethernet; Thread/OpenThread is mainly useful if you intentionally use a Thread network.

The V4 is prepared for Thread/OpenThread, but it ships with WiFi firmware by default. Ethernet firmware can be installed via our firmware page. Only use OpenThread when you have a suitable Thread network, matching firmware and Home Assistant configuration. WiFi or Ethernet/PoE remains the recommended choice for most installations.

Place the water sensor on your water meter using the universal holder, optionally connect the RJ12 cable to your smart meter's P1 port and connect the V4 to your network. By default you use WiFi. If you want Ethernet or PoE, install the Ethernet firmware through our firmware page.

The detachable water sensor with a 3-meter cable gives you more installation freedom. You can place the main unit near your smart meter or network connection and mount the water sensor exactly on the water meter. This is useful when your water meter and meter cabinet are not next to each other.

Yes. The V4 ships with WiFi firmware by default. If you want Ethernet, you can install the Ethernet firmware yourself through our firmware page. The hardware is the same; the firmware determines whether you use WiFi or Ethernet.

For a Thread network you need a Thread border router that connects your Thread network to your regular network and Home Assistant. Without such a Thread network, use the V4 via WiFi or Ethernet.

Yes. The V4 has an extra expansion port for an optional water leak sensor or door sensor. This sensor is sold separately and can be used in Home Assistant alongside your water and energy data.

You can power the V4 via USB-C or via PoE. PoE is convenient because power and network run over one Ethernet cable, but it requires a PoE switch or PoE injector. USB-C always works as an alternative power option.

Still have questions?

Get in touch with us

Contact Us
SPECIFICATIONS

Technical Specifications

Connection to Water and Energy Meter

- Water meter: Direct connection with a universal holder for mounting the detachable 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.
- Prepared for Thread/OpenThread via IEEE 802.15.4 radio. This is not Zigbee pairing and requires matching firmware, a Thread border router and Home Assistant configuration.

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.
- Water sensor cable: 3 meters with detachable water sensor.

Power Supply

- USB-C port for power supply (5V, 1A) with included USB adapter (if chosen).
- Alternative power supply 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 listed on our website; contact us if you are unsure.

Software

Fully integrated with Home Assistant. Ships with WiFi firmware by default; Ethernet firmware can be installed via our firmware page. Thread/OpenThread depends on matching firmware and network configuration.

Included

- Detachable water sensor with 3-meter cable.
- Universal holder with screws for easy installation on the water meter.
- RJ12 cable for DSMR energy meter.
- Quick Start Guide.

WaterP1MeterKit V4
2 year warranty
Shipped worldwide