East Idaho doesn't do gentle winters. From Idaho Falls to Rexburg to Island Park, January regularly delivers stretches below 0°F, and a hard freeze can arrive weeks before you expect it. Every one of those cold snaps finds the homes that skipped winterization — through a split hose bib, a burst crawl space line, or a cracked sprinkler manifold that doesn't reveal itself until spring.

The fix is an afternoon of preparation in early fall. Here's the complete checklist, roughly in the order the freeze will come for things.

Outdoors First: Hose Bibs and Exterior Lines

Exterior spigots freeze before anything else, and the most common failure is entirely preventable: a garden hose left connected. The hose traps water in the sillcock, the water freezes and expands, and the pipe splits just inside your wall — where you won't see the damage until you turn the spigot on next spring and water pours into the basement or crawl space.

  • Disconnect every hose by late September, drain them, and store them indoors. This is the single highest-value item on this list.
  • Shut off and drain hose bibs. If your bibs have interior shutoff valves, close them, then open the outdoor spigot to drain the stub of pipe. Leave the spigot handle slightly open through winter.
  • Add insulated bib covers. Cheap foam covers add a meaningful buffer, especially on north-facing walls. Frost-free sillcocks help too — but only if the hose is disconnected, which is why so many "frost-free" bibs still split.
  • Drain anything else outside: yard hydrants without proper drainage, outdoor kitchens, and drip irrigation lines.

Irrigation Blowout: Timing Matters

Sprinkler systems hold water in shallow lines, valves, and backflow preventers, and none of it survives a hard freeze. Simply shutting the system off isn't enough — the lines need to be blown out with compressed air.

In East Idaho, the window is typically late September through October: after your last mowing-season watering, but firmly before the first hard freeze, which can arrive in early October in colder pockets like Ashton, Driggs, or Island Park and a few weeks later in the Idaho Falls and Pocatello area. Don't push your luck for a few extra weeks of green lawn — a cracked backflow preventer or manifold costs far more than early dormancy.

A proper blowout uses a compressor with enough air volume to purge each zone, run one zone at a time until only mist comes out. Most homeowners book this out rather than buying a suitable compressor; if you want it handled, it's a routine fall request across our East Idaho service areas.

Crawl Spaces: East Idaho's Freeze Zone

A huge share of the region's housing sits on crawl space foundations, and the crawl space is where most in-home freezes happen. Any supply line running through that unheated cavity is exposed to near-outdoor temperatures for months.

  • Close foundation vents for winter. Open vents in January pour subzero air directly across your pipes. Close or cover them in late fall (and reopen in spring for moisture control).
  • Seal air leaks. Gaps around the crawl space access door, rim joist penetrations, and utility entries create wind-chill on pipes. Foam and caulk are cheap insurance.
  • Insulate the pipes themselves with foam sleeves — cover every run you can reach, with special attention to lines near vents and exterior walls.
  • Know what's down there. Ten minutes with a flashlight in October beats discovering the layout mid-emergency in January.

Heat tape: where it earns its keep

For lines that freeze despite insulation — long crawl space runs, pipes in exterior walls, well house plumbing on rural properties near Rigby or Shelley — electric heat tape or heat cable is the reliable fix. Use a thermostatically controlled product so it only draws power when temperatures approach freezing, install per the manufacturer's instructions (spacing, insulation over the top, no overlapping unless rated for it), and inspect it each fall before the season. Aging or damaged heat tape should be replaced, not patched.

Indoor Habits for the Cold Months

  • Keep the thermostat at 55°F or above, even when you're away. The savings from going lower aren't worth a burst line inside a wall.
  • Open cabinet doors under sinks on exterior walls during cold snaps so room heat reaches the pipes — the classic kitchen-sink freeze in older Idaho Falls and Pocatello homes.
  • Let vulnerable faucets drip on the coldest nights. Moving water freezes far less readily, and a pencil-thin stream relieves pressure even if ice starts forming.
  • Locate your main shutoff valve now and make sure it actually turns. In a burst-pipe emergency, minutes of searching equal gallons on your floor.
  • Fix small leaks before winter. A weeping fitting or sweating valve is a freeze nucleus waiting for a cold snap.

Leaving Town? Vacation and Vacant-Home Prep

An empty house in an East Idaho winter needs its own plan, because nobody's there to notice the first signs of trouble.

  • For a trip of a week or two: leave heat at 55°F or higher, open cabinet doors on exterior-wall plumbing, and have someone check the house every few days. Consider shutting off the main and briefly opening faucets to relieve pressure — then even a freeze has little water to work with.
  • For a house left vacant for the season (or a cabin in Swan Valley or Island Park): do a full winterization — main off, lines drained from the low point, water heater off and drained, and non-toxic RV antifreeze in traps and toilet bowls so the trap seals don't freeze and crack.
  • Consider leak detection tech: inexpensive Wi-Fi water sensors near the water heater, under sinks, and in the crawl space can turn a catastrophe into a phone alert.
  • On well systems, make sure the well house heat source is working before you leave — it's the single point of failure for the whole water supply.

If You Find a Frozen Pipe Anyway

Even well-prepared homes can lose a pipe in an extreme cold snap or power outage. The short version: confirm it's a freeze, open the affected faucet, know where your main shutoff is before you thaw anything, and warm the pipe gradually with a hair dryer or heat tape — never an open flame. If the pipe has split, shut off the main immediately and request emergency plumbing help; emergency requests are prioritized. The full step-by-step is in our guide: Frozen Pipes in East Idaho: What to Do Before the Plumber Arrives.

The One-Afternoon Checklist

  1. Disconnect, drain, and store hoses; shut off and drain hose bibs; add bib covers.
  2. Schedule the irrigation blowout for late September–October, before the first hard freeze.
  3. Close crawl space vents, seal air leaks, and insulate accessible pipe runs.
  4. Install or inspect heat tape on chronic problem lines.
  5. Verify the main shutoff valve works and everyone in the house knows where it is.
  6. Set winter thermostat habits and a vacation plan before the first trip out of town.

If you'd rather have a professional handle the blowout, insulate a crawl space's plumbing, or fix that hose bib that split last winter, tell us your city — from Idaho Falls to St. Anthony — and we'll route your request to an available local plumber.