Winterizing your sprinkler system correctly is the single most cost-effective thing you can do for your irrigation investment. A proper blowout costs a fraction of what a frozen manifold or cracked mainline costs to repair in the spring. Here's exactly what the process should cover.
When to winterize in Utah County
The target is before your first hard freeze — a sustained night below 28°F for more than a few hours. In Utah County valley communities (Provo, Orem, Spanish Fork), that's typically October. Bench communities (Highland, Alpine, Cedar Hills) and southern cities (Santaquin, Payson) can see hard freezes earlier. Don't wait until the forecast shows a freeze — booking gets difficult as October progresses.
The shutoff sequence
Before the blowout, turn off the water supply to the irrigation system at the main shutoff valve (usually near the backflow preventer). Set your controller to off or rain delay — not just the manual off — so it doesn't attempt to activate zones during or after the blowout. Disable any smart controller weather adjustments that might trigger a cycle.
The blowout itself
A compressed-air blowout connects to the system via a blow-out port (usually near the backflow) and forces air through each zone in sequence. Each zone should run for 2–3 minutes until no water exits the heads, then move to the next. The sequence matters — starting with the farthest zones first is generally correct, though the right order depends on your specific system layout.
Backflow preventer protection
Your backflow preventer sits above ground and is the most freeze-vulnerable component. After the blowout, close both shutoff handles on the backflow to 45 degrees (the standard winterized position) and open the small test cocks to release any trapped water. Wrap with foam pipe insulation if it's in an exposed location.
What to note for spring
Before closing up, note anything that looked off during the blowout — heads that didn't fully retract, zones with unusually low output, or valve boxes that are hard to access. A quick note on your phone saves time in spring when you're trying to remember what needed attention.