Water Monitor for Home Assistant (Marketplace integration)

Installs: 126 sharing analytics
GitHub stars: 63
Connection: Works locally
Upkeep: Updated in the last 6 months
Version: v1.4.1, October 6, 2026
Category: Water
Kind: Marketplace integration
Needs: Needs the Marketplace (HACS on 2026.10 and older)
Domain: water_monitor
Source: github.com/markaggar/Water-Monitor
Issues: Report an issue

Independent directory, made by the developer of Vulpo. Not affiliated with Home Assistant or the Open Home Foundation.

About

Water Monitor is a Home Assistant integration that tracks water usage sessions from an existing flow sensor and detects leaks. It requires only a flow sensor, while a volume sensor, a hot water binary sensor and a shutoff valve are optional. It adds session sensors for volume, duration, average flow and hot water percentage, with gap handling so one use is not split into several sessions. Two optional leak detectors are included: one looks for a continuous low-flow dribble, the other for repeated, similar-sized tank refills. Each detector can turn off a linked shutoff valve, and the leak sensors stay set while the valve is off. It works locally, is configured in the UI, supports multiple instances, and includes a number for injecting synthetic flow during testing.

Automatic summary of the README and code of markaggar/Water-Monitor. Something wrong, or are you the maintainer and want your own text here? Get in touch

Supports

Works locally Talks to your devices on your own network. No vendor cloud in between.
From the Marketplace Installed through the Marketplace, formerly HACS.
Actively maintained Its author released or pushed a change in the last six months.

Provides

Sensors

Setting it up

Install it from the Marketplace and restart Home Assistant, then add it under Settings, Devices and services.

Set up Water Monitor

Sensor name prefix
Flow sensor
Volume sensor (optional)
Hot water binary sensor (optional)
Water shutoff valve (optional)
Clear water shutoff valve
Clear volume sensor
Clear hot water sensor
Integration method (when no volume sensor specified)Only used when computing volume from the flow sensor. Trapezoidal (recommended) gives better accuracy on changing flow. Left matches external counters that tick once per update.
Minimum session volume
Minimum session duration (seconds)
Gap tolerance (seconds)
Treat baseline threshold as zero for session end
Baseline idle to close session (seconds)
Enable Synthetic Flow (testing)

Synthetic Flow

Include synthetic flow in detectors
Include synthetic in daily analysis

Intelligent Leak Detection

Occupancy mode input_select (optional)
Away states (comma-separated, optional)
Vacation states (comma-separated, optional)
Enable learning mode
Suppress detection during learning period
Minimum learning days before detection

Tank refill leak detection

Minimum refill volumeIgnore refills smaller than this.
Maximum refill volume (0 = disabled)Ignore refills larger than this (0 disables the cap).
Similarity tolerance (%)How similar volumes must be to be counted together.
Repeat count to triggerNumber of similar refills within the window required to trigger.
Maximum hot water percentage (%)Sessions with hot water percentage above this will be ignored.
Window to count repeats (seconds)Time window to collect refills for comparison.
Auto-clear after idle (seconds)Time without matching refills before the alert clears.
Cooldown after clear (seconds)Suppress re-triggering for this long after clearing.
Minimum refill duration (seconds, 0 = disabled)Ignore refills shorter than this (0 disables the guard).
Maximum refill duration (seconds, 0 = disabled)Ignore refills longer than this (0 disables the guard).
Turn off shutoff valve when leak is detected

Low-flow leak detection

Max low-flow rate
Seed low-flow duration (seconds)
Minimum duration to trigger (seconds)
Clear after idle (seconds at zero flow)
Counting modeChoose how time is accumulated during low-flow: - Any non-zero flow (wall clock): counts all time while flow > 0 - Only time within low-flow range: counts only while 0 < flow ≤ max low-flow - Baseline latch: once seeded, latches a baseline and counts while flow stays near baseline; margin controls the allowed band
Smoothing window (seconds)
Cooldown after clear (seconds)
Clear after sustained high flow (seconds, optional)
Baseline margin (%)
Turn off shutoff valve when leak is detected

After setup

Sensor name prefix
Flow sensor
Volume sensor (optional)
Hot water binary sensor (optional)
Water shutoff valve (optional)
Clear water shutoff valve
Clear volume sensor
Clear hot water sensor
Integration method (when no volume sensor specified)Only used when computing volume from the flow sensor. Trapezoidal (recommended) gives better accuracy on changing flow. Left matches external counters that tick once per update.
Minimum session volume
Minimum session duration (seconds)
Gap tolerance (seconds)
Treat baseline threshold as zero for session end
Baseline idle to close session (seconds)
Enable Synthetic Flow (testing)
Include synthetic flow in detectors
Include synthetic in daily analysis
Occupancy mode input_select (optional)
Away states (comma-separated, optional)
Vacation states (comma-separated, optional)
Enable learning mode
Suppress notifications during learning period
Minimum learning days before notifications
Suppress high usage notifications
Turn off shutoff valve when leak is detected
Minimum refill volumeIgnore refills smaller than this.
Maximum refill volume (0 = disabled)Ignore refills larger than this (0 disables the cap).
Similarity tolerance (%)How similar volumes must be to be counted together.
Repeat count to triggerNumber of similar refills within the window required to trigger.
Maximum hot water percentage (%)Sessions with hot water percentage above this will be ignored.
Window to count repeats (seconds)Time window to collect refills for comparison.
Auto-clear after idle (seconds)Time without matching refills before the alert clears.
Cooldown after clear (seconds)Suppress re-triggering for this long after clearing.
Minimum refill duration (seconds, 0 = disabled)Ignore refills shorter than this (0 disables the guard).
Maximum refill duration (seconds, 0 = disabled)Ignore refills longer than this (0 disables the guard).
Turn off shutoff valve when leak is detected
Max low-flow rate
Seed low-flow duration (seconds)
Minimum duration to trigger (seconds)
Clear after idle (seconds at zero flow)
Counting modeChoose how time is accumulated during low-flow: - Any non-zero flow (wall clock): counts all time while flow > 0 - Only time within low-flow range: counts only while 0 < flow ≤ max low-flow - Baseline latch: once seeded, latches a baseline and counts while flow stays near baseline; margin controls the allowed band
Smoothing window (seconds)
Cooldown after clear (seconds)
Clear after sustained high flow (seconds, optional)
Baseline margin (%)
Turn off shutoff valve when leak is detected

Texts from the code of markaggar/Water-Monitor.

Entities

NumbersExpected low-flow baseline, Leak alert sensitivity, Synthetic flow (gpm)

From the README

You must download/copy the integration first (via HACS or manual copy) and restart Home Assistant before you can install the integration from the Devices and Services page under Settings.
A Home Assistant custom integration for water usage monitoring that provides session tracking, gap handling, hot water analytics, and optional leak detection with water shut-off valve support. Only a Flow sensor is required; a Volume sensor, Hot water sensor and shut-off valve control is optional. If you do supply a Volume sensor, Water Monitor will use it directly (ideal if you want volumes to align with the Energy dashboard).
Intelligent session detection
Automatically detects water usage sessions from flow/volume sensors
Smart gap handling to avoid splitting single sessions
Session sensors
Last session volume: Most recently completed session with metadata
Current session volume: Real-time view during active use including gaps, and resets to 0 when a session ends
Last session duration: Duration in seconds of the last completed session
Last session average flow: Average flow rate of the last completed session (volume unit per minute)
Last session hot water percentage: Hot water percentage of the last completed session
Hot water analytics
Tracks hot water time and percentage per session via an optional hot water binary sensor
Optional low-flow leak detector