What does skipping sprinkler blowout before winter cost?
Updated August 2026
← What skipping home maintenance costs
A one-time fall blowout costs $50–120 from an irrigation pro, or nothing if you own the air compressor, while the freeze it prevents cracks backflow assemblies, splits manifolds, and snaps heads for $150–1,000+. Water is nearly incompressible and expands about 9% when it turns to ice, so any water trapped in your PVC lines, valves, or the brass backflow preventer becomes a wedge that splits the fitting from the inside. In freezing climates this is not optional maintenance; it is the difference between a $75 appointment and a spring dig-and-replace. Here is how the bill climbs the longer the water sits in the lines.
The escalation ladder
Every row below is the same leak, left a little longer. The top is a cheap warning; the bottom is a claim.
| What happens | Typical bill | How fast |
|---|---|---|
| You blow the lines out yourself with a rented compressor | $0–40 plus an hour | Before first freeze |
| A pro blows out the system and drains the backflow | $50–120 once a year | One fall visit |
| A few spray heads crack from leftover water | $10–30 each in parts | First hard freeze |
| A poly manifold or lateral line splits underground | $150–500 to excavate and repair | First deep freeze |
| The brass backflow preventer cracks | $150–400 for the assembly, more with labor | One freeze night |
| Several zones and the backflow all fail at once | $500–1,000+ to rebuild the head end | Over one winter |
Warning signs
The warning here is the calendar, not a symptom, because the damage happens out of sight and shows up only when you turn the system back on in spring. Watch the forecast for the first night that dips near 28°F or below, roughly the point at which shallow lines start to freeze, and treat that as your deadline. If you skipped the blowout, the tells arrive in April: a zone that will not build pressure, geysers erupting from cracked heads, a soggy patch of lawn over a split lateral, or water dribbling from the backflow's relief port. A backflow preventer that weeps or shows a hairline crack in the brass has already failed and must be rebuilt before it will hold pressure. By then the repair is booked; the blowout was the cheap move you missed in October.
The prevention math
The whole prevention budget is one $50–120 blowout each fall, or a rented compressor and an hour of your time, set against a spring repair that starts at $150 and climbs past $1,000 once the backflow and multiple zones are involved. Shut off the water to the system, insulate or drain the backflow preventer, and have the lines blown clear with compressed air before the first hard freeze; in cold climates that means finishing by mid-to-late October across most northern states. Booking it on a recurring reminder turns a forgettable fall chore into a fixed date. The sprinkler system maintenance checklist covers the full shutdown, and the lifespan of a sprinkler system shows how much winterizing adds to it.
Every line in that table starts with a skipped 10-minute task. OnOtto keeps the 10-minute version on your calendar so the $2,000 version never happens.
Get the nudge before the billFrequently asked questions
Can I winterize sprinklers myself without a compressor?
Partly. You can shut off the system's water supply, open the drain valves, and drain the backflow preventer by hand, which protects the low points. But gravity draining leaves water in flat runs and heads, so most pros still recommend a compressed-air blowout to clear the laterals fully. A small pancake compressor usually cannot move enough volume; you want 20–50 CFM, which means a towable unit or a rental at $40–80 for the day. If your lines lack proper drains or you cannot reach that airflow, the $50–120 pro blowout is the safer bet.
When exactly should I blow out my sprinklers?
Before the first hard freeze, which across most of the northern U.S. lands between early and late October. The trigger is nighttime lows reaching about 28°F, since a couple of hours below freezing will not hurt buried pipe but a hard overnight freeze reaches the shallow lines and the exposed backflow. It is better to winterize two weeks early and hand-water any late-season dry spells than to gamble on a surprise cold snap. Set a recurring reminder for the first week of October so the date does not slip past you.
Will my homeowners insurance cover frozen sprinkler damage?
Usually not for the irrigation system itself. Most policies treat a cracked backflow or split sprinkler line as a maintenance failure rather than a covered peril, so the $150–1,000+ repair comes out of pocket. Insurance is more likely to step in only if the failure floods a finished space, and even then the neglected-maintenance exclusion can apply. That gap is exactly why the cheap fall blowout matters: it is a predictable expense you control, versus an uncovered repair you do not. Read your specific policy language before assuming any of it is covered.