Garage & workshop sensor monitoring

ThermalTrace

Know before your pipes freeze or your garage floods.

ThermalTrace watches temperature and leak sensors in garages, workshops, attics, crawlspaces, and shops, with live charts, history, and freeze, leak, and heat alerts. Open source, with a free plan.

Start free See the live demo

No credit card. Connect Home Assistant, ESPHome, or MQTT in minutes, or build the ~$25 ESP32 freeze kit. No hardware yet? Cause a cold snap in the simulator.

Free forever · no credit card Member $4/mo Pro $10/mo

ThermalTrace Insights: seven-day probe curves with the freeze line, flood/wet contacts, nights-at-risk forecast, and forecast-backed time-to-freeze clock
Real ThermalTrace dashboard: probe curves, freeze threshold, and flood/wet contacts, not a mockup. Try the interactive simulator · Live readings
All systems operational

Two ways to try it (no account)

Hands-on: Interactive probe simulator to open the bay door, trigger a cold snap, and watch multi-zone risk and push/pull JSON respond. Observational: live demo probes below on the production ingest path. Full live page (weather + kit steps): /demo.

Try a cold snap Want this for your garage? Live demo feed

Loading probe temperatures…

Loading outdoor weather…

How it works

One recommended path: ESP32 + waterproof probe → ThermalTrace → phone alert. Other boards and feeds stay supported after you are live.

  1. Build one probe

    ESP32 + waterproof DS18B20 is the default kit (~$20–30 parts). Wire it, flash Wi‑Fi, and you are ready to POST.

  2. Connect

    Create a free push device, paste the ingest key into the sketch, and POST once. Sensors auto-import on first contact.

  3. Get freeze alerts

    Set freeze °F + email, send a test, then watch Live and Overview. Add a flood/leak contact when you are ready.

ESP32 freeze kit BOM Start free All device options

What you need

Monitor an unheated garage for under about $25 in parts. No subscription required to try freeze alerts.

Parts

  • ThermalTrace account — free, no credit card
  • ESP32 board — about $8–15
  • Waterproof DS18B20 — about $2–5
  • Wi‑Fi — your existing home network

What you get

  • Live garage temperature on phone and web
  • History curves with a freeze line
  • Freeze alerts (email and push on Free; SMS on Pro)
  • No home server to babysit
Open the parts list Try the simulator first
ThermalTrace Devices page showing Garage pull device health and connection options
Devices. ESP push, pull feeds, MQTT, and Home Assistant.
ThermalTrace Overview Status strip with last reading, sensors, feeds, alerts, house, freeze hours, coldest margin, indoor−outdoor delta, probe spread, condensation, and feed health
Overview Status: freeze margin, ΔT, probe spread, condensation, and feed health.

Love DIY? You don’t have to DIY everything.

Keep your ESP32, Arduino, MQTT, or Home Assistant setup. ThermalTrace adds hosted history plus household freeze and flood alerts without another server to babysit.

Your sensor. Your data. Your alerts.

Scenario

34°F. That’s when the alert matters.

Picture an attached garage where one corner dips below 34°F every clear night. The alert says something is wrong; the history chart shows where, pointing at a drafty door seal before supply lines ice. That is exactly the kind of timeline a claims evidence pack would document if freeze damage ever became an insurance conversation.

ThermalTrace temperature trend with humidity percent, dew point overlay, house thermostat reference, and 34°F freeze line
The same freeze line households set in Alerts, visible on History curves.

Read the scenario Claims evidence pack More scenarios

Built for the messy middle

Homemakers wiring one garage, and landlords watching a portfolio: same cold-and-water problem, different scale.

Claims evidence pack

Pro exports a printable freeze/leak summary with matching readings and alert CSVs for a date range you choose: monitoring evidence when you need more than a screenshot.

See the claims pack

Property managers

Portfolio raises owned-property limits and adds property-manager logins for on-site staff so rentals and multi-unit sites share one freeze-and-flood alert stack.

Property management

Protect vulnerable spaces

Freeze and leak alerts on every plan, plus a time-to-freeze clock for this space so you know when pipes will hit freeze, not only after they do. Member adds outdoor forecast warnings; Pro adds official NWS alerts and SMS. Cold-snap playbook

Catch leaks before they spread

Flood / leak contacts auto-alert when wet, even during snooze or vacation. Add a sump or tank level sensor if you want early-warning rules before water reaches the floor. Flood + level ingest guide

Your sensors, your stack

Temperature, humidity, air quality, doors, leaks, power, and motion on hardware you control. Ingest guide · HTTP API

Household ready

Invite family and share one free live link without handing out a password. Pro expands share scopes and adds a claims evidence pack.

Free to start

Pick a rung by job, whether that is freeze nights, wet leak alerts, or portfolio monitoring. Full limits live on pricing.

  • Free See if ThermalTrace works for you
  • Member Track a whole cold season · $4/mo
  • Pro Serious alerts and automation · $10/mo
Compare plans Start free

Works on your phone today

Install the web app (PWA)

ThermalTrace works now — add it to your home screen in Chrome or Safari. Same account, live readings, and alerts. The native Android app is next; you do not need to wait on Play.

  1. Open thermaltrace.dev in Chrome (Android) or Safari (iPhone).
  2. Use Install app or Share → Add to Home Screen.
  3. Open the icon; enable push later from Dashboard → Alerts.

PWA install steps Android native (coming)

Guides by job

Start with the job you need done, or open the hub for every guide.

Open the guides hub All articles

Open-source dashboard and sample sensor sketches. View source on GitHub.

Frequently asked questions

Straight answers for homeowners wiring probes, wet contacts, and setting freeze or flood alerts.

What is ThermalTrace?

ThermalTrace is open-source freeze and flood monitoring for garages, workshops, attics, crawlspaces, and shops: ESP/Arduino ingest, live curves, and alerts. Build with ESP32, Pico W, or Arduino; ThermalTrace handles the hosted dashboard, history, and household alerts.

How do I connect ESP32, Pico W, or Arduino sensors?

Create a push device under Dashboard → Devices, copy the ingest key from the callout (or use Reveal ingest key later), POST JSON to /api/ingest/<key>, and sensors auto-import on first POST. ESP32, Pico W, and Arduino Ethernet samples live on thermaltrace.dev/about/adding-devices. No hardware? Try the demo pull quick start on Overview.

Does ThermalTrace send freeze alerts?

Yes. Set a freeze threshold and enable channels such as email, browser or Android push, Discord, Telegram, Slack, or (on Pro) SMS and WhatsApp. Remaining-hours time-to-freeze alerts fire before the probe crosses freeze, using this space's lag vs the outdoor forecast (details: thermaltrace.dev/about/time-to-freeze). Predictive outdoor forecast freeze alerts are on Member; official NWS freeze and cold alerts are on Pro. Leak / flood sensors also notify automatically when wet; door, motion, power, and air quality use custom rules. With a Telegram bot webhook, you can reply /status, /snooze, or /vacation from chat.

Is ThermalTrace free?

Yes, there is a free plan with live curves, 7-day history, threshold freeze and leak alerts by email and push, and one family live share link (7-day expiry). Member adds 90-day history, CSV export, more devices, and forecast freeze warnings; Pro adds 1-year+ history, official NWS freeze and cold alerts, SMS, unlimited share scopes (history, metrics, never-expire), a printable claims evidence pack, webhooks, and a trial. Annual Member and Pro billing is discounted versus monthly.

Why do I need an account?

An account links your ingest keys, history, and alerts to your household: it is how we keep your probes private. Registration is free with no credit card. You can try the interactive probe simulator or watch the live demo without signing up; create an account when you are ready to connect your own hardware.

Is there a ThermalTrace Android app?

A native Android app is available in early access on GitHub while Google Play review finishes. You can also use the full web dashboard or install the Progressive Web App. Companion clients (Android, Desktop, Bay Buddy, PWA) are listed at thermaltrace.dev/apps. The phone and desktop apps do not sense temperature: they connect to your ThermalTrace account.

Where is ThermalTrace hosted?

On Cloudflare’s edge network (Workers), so the site and ingest APIs run close to visitors without you maintaining a VPS. Live job and ingest health is on thermaltrace.dev/system-status: we publish what we measure, not a marketing uptime percentage.