Answers
Freezing pipes and freeze alarms, answered
Short, direct answers first, then the detail. Sources are linked where a number comes from research or a vendor.
At what temperature do pipes freeze in a garage?
Water freezes at 32°F, but garage pipes usually freeze when it drops to about 20°F outside. Why, what speeds it up, and where to set an alert.
What temperature should a freeze alarm be set to?
Set a freeze alarm to 34–38°F measured at the pipe. When to go lower or higher, and how to avoid false alarms without losing warning time.
Where should a freeze sensor go in a crawlspace?
Put a crawlspace freeze sensor on the coldest water supply line, usually near vents or where pipes enter, not at the access hatch. How to mount it.
How do I set up a freeze alert in Home Assistant?
A Home Assistant freeze alert is one automation: trigger when a temperature sensor stays below 35°F for 10 minutes, then notify your phone. YAML inside.
Can I get a freeze alarm without a monthly subscription?
Yes. Temp Stick, Govee, Home Assistant, and ProbeHarbor's free plan all alert without a subscription. What each costs and what you give up.
How long does it take for pipes to freeze?
There is no fixed number: pipes need hours of sustained cold, usually with outdoor temperatures near 20°F or lower. What shortens it and how to see it coming.
What temperature should I leave my house at in winter when I am away?
Leave the heat on, set no lower than 55°F, per the American Red Cross. Why 55°F is not a guarantee, and how to know if the heat fails while you are gone.
Should I let faucets drip to prevent frozen pipes?
Yes, in very cold weather: let cold water drip from faucets served by exposed pipes. Which faucets, how much, and what a drip cannot do.
How do I thaw a frozen pipe safely?
Keep the faucet open and warm the pipe with a hair dryer, heating pad, or hot towels. Never use an open flame. Steps, and when to call a plumber.
Will a Wi-Fi freeze alarm work during a power outage?
Usually not: a power cut takes down the router even if the sensor has batteries. How silence alerts, battery backup, and cellular sensors cover the gap.
How can I monitor the temperature in a cabin remotely?
With internet at the cabin, a Wi-Fi sensor that alerts your phone. Without it, a cellular sensor. What to measure, where, and who should get the alert.
DS18B20 or DHT22: which sensor is better for freeze monitoring?
The DS18B20: it comes as a sealed waterproof probe you can tape to a pipe, and several share one pin. The DHT22 adds humidity but only measures room air.
How do I build a freeze alert with ESPHome?
Add a DS18B20 to an ESP32 with ESPHome's dallas_temp sensor, then alert through Home Assistant or post the readings to an off-site service. YAML inside.
Where should water leak sensors be placed?
On the floor at the lowest point next to each water source: water heater, washing machine, under sinks, sump pit, and below pipes that could freeze.
How can a landlord monitor a vacant rental for frozen pipes?
Keep the heat at 55°F or higher, put a temperature sensor near the plumbing in each unit, and send alerts to whoever can get there first.