# Sprinkler winterization: when to blow out your lines (and why)

> Water left in sprinkler pipes can freeze and crack them. Here's when to winterize, how a blowout works and what to ask a pro.

Source: https://bluecollarposts.com/blog/sprinkler-winterization-when-and-why · Published 2026-11-12 · By Blue Collar Posts

**Quick answer:** Winterize your sprinkler system before the first hard freeze in your area. A pro shuts off the water and uses compressed air to blow the water out of every zone, so nothing is left to freeze and crack.

If you live where winters freeze, your sprinkler system needs one job every fall: getting the water out.

## Why winterize a sprinkler system?

Water expands when it freezes. Water left in pipes, valves and sprinkler heads can crack them, and you won't know until you turn the system on in spring and find leaks, soggy patches or zones that don't work.

## When should I winterize?

Aim for **before the first hard freeze**, not just the first frosty morning. In many northern areas that's October or November; in milder areas it may be later. Local sprinkler companies know the usual timing for your area and fill their schedules quickly.

## How does a sprinkler blowout work?

1. The water supply to the system is shut off.
2. An air compressor is connected to the system.
3. Each zone is opened in turn and blown out until only air comes out of the heads.
4. The controller is set to off or winter mode.
5. Backflow devices and exposed pipes may be drained or insulated.

## Can I do it myself?

It's possible, but it needs the right compressor and care: too much air pressure can damage pipes and heads. Many homeowners book a pro and add a spring start-up visit at the same time.

## What should I ask a pro?

- Do you blow out every zone, including drip lines?
- Do you protect the backflow device?
- Can I book the spring start-up now too?

[Find sprinkler winterizing near you](https://bluecollarposts.com/pros?service=sprinklers).

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Find local pros for Sprinkler start-up and winterizing, Lawn care / mowing: https://bluecollarposts.com/pros?service=sprinklers