Denver's first hard freeze usually shows up in October — sometimes overnight, right after a 75-degree afternoon. Any water still sitting in your sprinkler lines, valves, or backflow preventer freezes, expands, and cracks things that are expensive to replace in April.
We blow out residential and small commercial irrigation systems across Denver, Thornton, Arvada, Westminster, Broomfield, and the rest of the metro. Book online or call, and we'll lock in a day before the cold shows up. You get the price when you book — before anything starts. You don’t need to be home — just tell us where the shutoff and backflow are, leave the gate unlocked, and we’ll text you when it’s done.
What's included
- Shut off and isolate — the irrigation supply valve is closed and the system isolated from your house water
- Blow out every zone — compressed air at a regulated pressure, zone by zone, until the heads run dry
- Protect the backflow preventer — drained, with test cocks left partly open so trapped water can't crack the body
- Controller set to off for the season, so nothing tries to run on a frozen system
- A heads-up on anything broken — cracked heads, leaking valves, a failing controller — with photos, so it's handled before spring
What a skipped blowout looks like in spring
- Water spraying from the backflow preventer when you turn the system on
- A soggy spot or a geyser in the lawn from a split lateral line
- A zone that won't shut off, or won't come on
- Heads that are cracked or won't pop up
- A water bill that jumps from a leak you can't see
When to book
Before the first hard freeze. In the Denver metro that's usually October, and most homeowners book from late September through October. If you're up toward the foothills — Golden, west Arvada, west Lakewood — book on the early side; it often freezes there first. Full timing guide →
A single light frost usually isn't the problem. A hard freeze — several hours well below 32°F — is what cracks backflow preventers and lines. If the forecast is calling for one and you haven't booked yet, call.
Denver Water customers: lawn watering and spray irrigation ended after Sept. 30, 2026, and Denver Water says sprinklers need to stay off into spring 2027. Turning the controller off doesn't drain the water already in the lines and backflow preventer, so the system still needs to be blown out before it freezes. There's no reason to wait. 2026–27 watering rules by provider →
Why not DIY it?
Most home and shop compressors can't move enough air volume to fully clear a zone, so water stays in the low spots. Too much pressure is the opposite problem — it can blow apart fittings and heads. And the backflow preventer is easy to leave full of water, which is exactly the part that cracks most often.
The backflow preventer
The backflow preventer is the brass assembly, usually near the house where the irrigation line comes up out of the ground. It keeps lawn water from siphoning back into your drinking water. It's also the most freeze-sensitive, most expensive piece of most residential systems. Draining it correctly and leaving the test cocks partly open is a big part of what you're paying for.
Spring startup
In spring we bring the system back online the right way: slow refill so the lines don't get hammered, every zone checked, heads adjusted, and the backflow device checked for damage. Book a spring startup any time.
Property managers and HOAs
Managing several properties? We'll schedule blowouts across your whole portfolio in one pass, document each system with photos, and invoice net-30 on one statement.
Sprinkler blowouts by city
Timing and system types vary across the metro. Pick your city for local details.
From our Google reviews
“Gabe is great!! He found and fixed a major leak in our sprinkler system that even a well known sprinkler service company couldn’t find. Highly recommend.”