Short answer
The strongest predictors of a frozen pipe are all findable in advance: plumbing running through a space the building's heating does not reach, a building left empty for days during winter with nobody watching it, and a pipe that has frozen in that same location before. A pipe does not freeze at random; it freezes where it runs through a space added or adapted without the insulation the rest of the building has, such as an exterior wall cavity, an enclosed porch, a crawlspace under a later extension, or a garage ceiling.
Replacing the split section without changing anything about that space leaves the same conditions in place for next winter. The checker takes what applies to your building and returns the specific actions that address those factors, in the order they matter, not as a generic winter checklist, and it makes the case for addressing them before the first hard freeze rather than during one, since during is when everyone else with the same problem is calling too.
The short answer
| Predictor | Why it matters |
|---|---|
| Plumbing outside the heated envelope | Exterior walls, enclosed porches, crawlspaces and garage ceilings run colder than room air |
| Building left empty for days in winter | Nobody is there to notice a falling temperature or a dripping faucet |
| A pipe that has frozen there before | The conditions that caused it are usually still present unless the space itself changed |
Why a freeze repeats in the same place
A pipe does not freeze at random. Replace the split section without changing anything about that space and the conditions that caused it are all still there for next winter.
That is why the useful question after a freeze is not 'is it fixed' but 'what changed about where it happened'.
If it has already frozen
Never use an open flame to thaw a pipe. Torches cause structure fires and it is the single most common way a frozen pipe becomes a much larger problem. If flow has stopped but nothing is leaking yet, be aware the split may only reveal itself as the ice thaws: watch for water once flow returns. If water is running and you can safely reach the main shutoff, close it first.
Common questions
Does this send my answers anywhere?
No. The whole thing runs in your browser, with no network request and nothing stored.
My pipes froze once but it has been fine since. Am I safe?
Not necessarily: a building that froze once has a route that can freeze again, and whether it does depends mainly on how cold it gets and for how long. The question worth answering is what changed about that space after the last time.
How low can I set the thermostat when away?
Set the floor by what the plumbing tolerates, not the rooms. Pipes sit in wall cavities and crawlspaces colder than room air, so the thermostat reading is not the pipe's temperature. If the building will be empty for days, a monitored sensor is worth more than any particular setting.
Is it better to drain the building instead?
For a building empty all season, usually yes: draining removes the risk instead of managing it. Complete draining is what protects the building, including the water heater with its power or fuel switched off first; anything less gives confidence without protection.
What are the strongest predictors of a frozen pipe?
Plumbing outside the heated envelope, since exterior walls, enclosed porches, crawlspaces and garage ceilings run colder than room air; a building left empty for days in winter, where nobody is there to notice a falling temperature or a dripping faucet; and a pipe that has frozen in that place before, because the conditions that caused it are usually still present.