Colorado’s fall can feel deceptively mild. You might still be enjoying sunny afternoons in October when the forecast suddenly calls for freezing temperatures overnight. If water is still sitting inside your sprinkler lines, valves, or backflow preventer, that first freeze can cause damage you may not discover until spring.
Knowing how to winterize your sprinkler system before the first hard freeze can help protect your investment. Proper sprinkler system winterization involves more than shutting off the water supply. From preparing the controller to arranging a professional sprinkler blowout, here’s what you need to know before freezing temperatures arrive.
Key Takeaways
- Prepare your sprinkler system before the first hard freeze, as Colorado’s fall temperatures can change quickly.
- Shutting off the water supply does not necessarily remove water trapped inside irrigation lines.
- A sprinkler blowout uses compressed air to clear residual water from suitable irrigation lines.
- Backflow preventers and exposed components may require separate winterization procedures.
- Scheduling sprinkler system winterization early in fall can help you avoid last-minute service appointments.
Why Should You Winterize Your Sprinkler System Before the First Freeze?
As fall gives way to winter, water left in your irrigation system can become a problem. When temperatures fall below freezing, trapped water can expand and crack pipes, fittings, sprinkler heads, and valves.
The damage may not be immediately visible. You could turn on your system the following spring and discover a leaking valve, a broken sprinkler head, or a section of lawn that stays unusually wet.
For example, imagine shutting off your sprinklers in October because you no longer need to water your lawn. If water remains trapped in an underground pipe, a cold spell could still damage it, even though the system hasn’t been running.
Winterizing your sprinkler system before freezing weather arrives helps protect vulnerable components while giving you time to arrange the necessary service.
When Should You Winterize Your Sprinkler System in Colorado?
In Colorado, the ideal time to winterize your sprinkler system depends on your location, elevation, and the approaching weather.
September and October are common planning periods, but there is no single date that works for every property. Higher-elevation areas and locations exposed to colder conditions may need earlier preparation.
As fall progresses, keep these points in mind:
- Watch overnight forecasts: A sudden temperature drop can put exposed irrigation components at risk.
- Don’t rely on daytime temperatures: A sunny afternoon does not mean your system is safe from a freezing night.
- Book a sprinkler blowout early: As the first freeze approaches, professional service appointments can fill up quickly.
- Don’t wait for frozen ground: The goal is to prepare the system before freezing conditions cause damage.
For example, if you see freezing temperatures in the forecast for the coming week, contact an irrigation professional rather than waiting until the night before.
How to Winterize Your Sprinkler System Before Winter
If you’re wondering how to winterize sprinkler system components before Colorado’s first freeze, start by shutting off the water supply and preparing the controller. You’ll also need to remove residual water from the irrigation lines and protect exposed components. The exact process depends on your system’s design and the equipment it uses.
1. Shut Off the Irrigation Water Supply
Locate the dedicated shutoff valve supplying your sprinkler system and close it according to the manufacturer’s instructions.
Depending on your property, the valve may be in a basement, crawlspace, utility area, or underground valve box.
Shutting off the water prevents additional water from entering the system. However, it does not necessarily empty the pipes.
For instance, you might turn off the supply in October and assume your system is ready for winter. If water remains trapped in a low section of pipe, it can still freeze and cause damage.
2. Set the Irrigation Controller for Winter
Once the system has been shut down and winterized, adjust the controller according to the manufacturer’s instructions.
Depending on the model, this may involve using an off, rain, or seasonal shutdown setting. Don’t automatically unplug the controller, as some models need to retain power to preserve their settings.
The aim is to prevent scheduled watering from resuming while the system is shut down for winter.
3. Remove Water From the Irrigation Lines
This is one of the most important parts of sprinkler system winterization.
Some systems use manual or automatic drain valves. However, these may not remove all the water, particularly if the pipes have low spots where water can collect.
Many in-ground sprinkler systems in Colorado require a compressed-air blowout to clear residual water from the irrigation lines.
A blowout must be performed using suitable equipment and pressure. Incorrect technique can damage sprinkler heads, pipes, fittings, and valves. If you’re unfamiliar with your system, arrange for a qualified irrigation professional to handle this step.
4. Protect the Backflow Preventer and Exposed Components
Backflow preventers protect the water supply from contamination, but exposed assemblies can be vulnerable to freezing.
Their winterization requirements depend on the type of device and the system configuration. Some need to be drained separately, and certain assemblies can be damaged if compressed air is forced through them.
After the irrigation lines have been cleared, exposed backflow preventers, valves, and pipes should be drained and protected according to the manufacturer’s instructions.
Insulation may help protect exposed components, but it should not replace the required draining procedure.
5. Prepare Pumps and Other Equipment Separately
If your irrigation system uses a pump, it may need additional winter preparation.
Depending on the installation, the pump may need to be drained, removed and stored indoors, or protected according to the manufacturer’s instructions.
Check the requirements for any other equipment connected to the system. A standard blowout does not automatically prepare every component for freezing temperatures.
What Is a Sprinkler Blowout, and Why Is It Important Before Winter?
A sprinkler blowout uses compressed air to push residual water out of irrigation lines before freezing weather arrives.
During a professional blowout, a technician connects suitable compressed-air equipment to the system’s designated connection and clears the irrigation zones individually. The process must be controlled to remove water without damaging the equipment.
This is particularly important when underground pipes retain water that gravity drainage cannot remove.
Imagine your backyard has several irrigation zones, with some pipes running through lower sections of the property. Even if the main water supply is shut off, water may remain in those lines. If temperatures fall below freezing, that trapped water can expand and damage the pipes.
A properly performed blowout helps reduce this risk.
However, compressed air must be used correctly. Excessive pressure or prolonged airflow through an already-cleared zone can damage components. Backflow devices may also require separate procedures.
This is why a professional sprinkler blowout is worth considering before Colorado’s first hard freeze, particularly if you’re unfamiliar with your system.
How to Blow Out a Sprinkler System: Should You Do It Yourself?
If you’re researching how to blow out sprinkler system lines before winter, you may be wondering whether you can handle the job yourself. Before attempting a DIY blowout, you need to understand your system’s layout, the compressor’s airflow and pressure limits, and which components require separate draining procedures.
It may be possible if you have the right equipment, experience, and understanding of your irrigation system. However, connecting an air compressor and increasing the pressure until water stops coming out is not a safe approach.
Before attempting a DIY blowout, you need to understand:
- Your irrigation system’s layout and individual zones
- The compressor’s required airflow and safe pressure limits
- The location of the designated blowout connection
- Which components need to be isolated or drained separately
- The manufacturer’s limits for sprinkler heads, pipes, valves, and fittings
For example, an undersized compressor may fail to clear the lines effectively, while excessive pressure can damage pipes or sprinkler heads.
Backflow preventers require particular care because some must be drained separately. If you’re unfamiliar with your system or unsure about the correct procedure, hiring an experienced irrigation professional is the safer option.
What Can Happen If You Miss the Winterization Window?
Colorado’s first freeze can arrive before you expect it. If your sprinkler system still contains water when temperatures drop, several components may be vulnerable to damage.
| Component | Potential freeze damage |
| Underground pipes | Cracks that may cause leaks when the system is used again |
| Sprinkler heads | Cracked housings or damaged internal parts |
| Valves and fittings | Leaks or broken connections |
| Backflow preventer | Damage to the assembly or its internal components |
| Exposed pipes | Cracks caused by freezing water |
You may not discover the problem until the next watering season. For example, a damaged underground line could cause water to pool in one part of your yard when the irrigation system is turned back on.
Preparing your system before freezing temperatures arrive helps reduce the likelihood of these problems.
Should You Hire a Professional for Sprinkler System Winterization?
Professional help can be particularly useful if your system has multiple irrigation zones, a complex backflow assembly, or components you’re unfamiliar with.
An experienced technician can use appropriately sized equipment, clear the irrigation zones, and follow the correct procedures for backflow devices and other exposed components.
Scheduling early in fall also gives you more flexibility if you need to arrange service before a sudden temperature drop.
If you aren’t confident about the equipment or procedure required for a sprinkler blowout, professional winterization is a practical way to reduce the risk of freeze-related damage.
Conclusion
Colorado’s first freeze can arrive quickly, leaving little time to prepare an irrigation system that still contains water. Winterizing your sprinkler system before temperatures drop helps protect pipes, valves, sprinkler heads, and exposed components from freeze damage.
Plan your sprinkler system winterization early in fall, and arrange a professional blowout if your system requires one. Preparing your system before winter sets in can help protect its components and reduce the risk of unexpected repairs when spring returns.
Frequently Asked Question
When should you winterize your sprinkler system in Colorado?
Winterize your sprinkler system before the first hard freeze that could damage its components. September and October are common planning periods, but the ideal timing depends on your location, elevation, and local weather forecast. Monitor temperatures and schedule service before freezing conditions arrive.
How do you winterize a sprinkler system?
Shut off the irrigation water supply, set the controller for winter, and remove residual water using the appropriate drainage or blowout method. Protect exposed components according to the manufacturer’s instructions. Many in-ground sprinkler systems in Colorado require a professional compressed-air blowout to reduce freeze damage.
Is a sprinkler blowout necessary in Colorado?
Many in-ground sprinkler systems in Colorado need a blowout because manual or automatic drain valves may leave water trapped in the lines. A professional uses compressed air to clear suitable irrigation lines. The correct winterization method depends on your system’s design and equipment.
Can I use a regular air compressor to blow out my sprinkler system?
Not every air compressor is suitable for sprinkler winterization. Your equipment must provide the appropriate airflow at a safe pressure for your system. Excessive pressure can damage pipes, valves, fittings, and sprinkler heads. If you’re unsure about the requirements, hire an irrigation professional.
What happens if I only shut off the sprinkler system’s water supply?
Shutting off the water supply prevents additional water from entering the irrigation system, but it doesn’t necessarily empty the pipes. Water trapped inside pipes, valves, and sprinkler heads can freeze, expand, and cause damage. Proper winterization removes residual water from vulnerable components before freezing temperatures arrive.