When to winterize sprinklers in Utah
A proper fall blowout is what prevents the most common — and most avoidable — irrigation failure we see in the Salt Lake Valley. Here's the timing and why it matters.
Irrigation winterization — a 'blowout' using compressed air to clear water from the lines, valves, and backflow preventer — needs to happen before the first hard, sustained freeze, which typically means sometime in October for most of the Salt Lake Valley. Waiting until after a hard freeze already hit is waiting too long.
Why this is the single most avoidable irrigation failure
Water left in a line, valve, or backflow device expands when it freezes, and something cracks. It's often not obvious until spring, when you turn the system back on and get a soaked yard, a dead zone, or no pressure at all from a component that failed months earlier. An incomplete or skipped blowout is the most common cause of the spring sprinkler repair calls we get, by a wide margin.
What a proper blowout actually involves
Compressed air gets pushed through the system at a pressure suited to the pipe material — done correctly, this clears water from the mainline, every zone's lateral lines, and the backflow preventer above grade, which Utah plumbing code requires on irrigation systems. Rushing this or skipping a zone is how water gets left behind in exactly the spot that fails first.
What to do if you missed it
If a hard freeze already happened and your system wasn't blown out, don't just try running it in spring to 'see what happens' — if there's cracked components, running pressurized water through them can make the damage and the mess worse. Have it inspected before you turn it back on for the season.