Scenario · Crawlspace under a house, cold climate

A crawlspace vent sticks open overnight

Scenario: a foundation vent sticks open on a cold night. How a waterproof DS18B20 on the supply line and ProbeHarbor freeze alerts give you time to close it.

Illustrative scenario. This is a walkthrough of how ProbeHarbor behaves in a common failure, not an account from a real customer. The features, thresholds, and plan limits are real.

Blue PEX and copper water lines with valves in a basement ceiling
Supply lines in basements and crawlspaces are the freeze risk that history charts prove. Photo: Tomwsulcer. CC0

The setup

  • ESP32 + waterproof DS18B20 zip-tied near the main supply run
  • Freeze threshold 36°F with email and SMS (Pro)
  • Family live link for a relative who lives nearby

How it plays out

  1. Sun 4:05 a.m.: The crawlspace crosses 36°F with a foundation vent stuck open.
  2. Sun 4:06 a.m.: SMS and email go out; the nearby relative checks the live link and heads over.
  3. Sun 5:20 a.m.: The vent is closed and the chart starts climbing before the morning low.

Why it matters

Nobody checks a crawlspace at 4 a.m. A probe on the pipe run, not at the hatch, is what turns a stuck vent into a quick fix.

Real outcomes depend on sensor placement, thresholds, and how quickly someone can respond.

FAQ

Where should the crawlspace probe go?

On or next to the coldest supply line, not at the access hatch. Add a living-space probe if you want context from upstairs.

Is a humidity sensor enough?

No. Humidity helps spot moisture, but freeze risk is the temperature at the pipes. Use a waterproof probe and a threshold a few degrees above 32°F.

Related answers

Try it on your space

Start free with live charts, email alerts, and one family live share link. Upgrade when you want CSV history (Member) or SMS and expanded share scopes (Pro: 14-day trial).

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