How to Blow Out Your Irrigation System for Winter: A Comprehensive Guide
Learn how to blow out an irrigation system properly to prevent costly winter damage! This guide details the essential steps, tools, and precautions necessary to effectively winterize your sprinkler system using compressed air.
Why Bother Blowing Out Your Irrigation System?
Winterizing your irrigation system is crucial in climates where temperatures drop below freezing. Water left in the pipes, valves, and sprinkler heads can freeze and expand, leading to cracks, breaks, and costly repairs in the spring. Failing to properly blow out your irrigation system can result in thousands of dollars in damage.
Benefits of Winterizing Your Irrigation System
- Prevents Freezing Damage: The primary benefit is preventing frozen pipes and sprinkler heads.
- Saves Money: Avoiding repairs due to freezing saves you significant money.
- Extends System Lifespan: Proper winterization extends the life of your irrigation system components.
- Peace of Mind: Knowing your system is protected allows you to relax during the winter months.
Tools and Materials You’ll Need
- Air Compressor: A compressor with sufficient CFM (cubic feet per minute) is essential. The required CFM will vary based on your system’s size and complexity. Consult your system’s manufacturer or a local irrigation professional for guidance.
- Adaptor Fittings: You’ll need fittings to connect the air compressor to your irrigation system’s blow-out port or point of connection.
- Safety Glasses: Protect your eyes from debris.
- Wrench or Pliers: For tightening fittings.
- Screwdriver: May be needed to open valves.
- Timer or Watch: To monitor the blow-out time for each zone.
- Optional: Teflon Tape: To ensure a good seal on fittings.
Step-by-Step Guide: How to Blow Out an Irrigation System
- Turn Off the Water Supply: Locate and shut off the main water supply to your irrigation system. This is usually located in a meter box or inside the house.
- Locate the Blow-Out Port or Connection Point: This is where you’ll connect the air compressor. If your system doesn’t have a dedicated blow-out port, you may need to connect at the backflow preventer or another point in the system.
- Attach the Air Compressor: Connect the air compressor to the blow-out port using the appropriate adaptor fittings.
- Adjust the Air Compressor Regulator: Start with a low pressure (e.g., 30-40 PSI) and gradually increase it if necessary. Never exceed the maximum pressure rating of your system components. Generally, PVC pipe can handle higher pressures than poly pipe. Consult with an irrigation professional if unsure.
- Open the Zone Valves Manually or Using the Controller: Begin with the zone farthest from the compressor. Open the valve manually, or set the irrigation controller to activate that zone.
- Blow Out Each Zone Individually: Allow the air compressor to run until only a fine mist or no water emerges from the sprinkler heads in that zone. This usually takes 2-3 minutes per zone.
- Repeat for All Zones: Repeat steps 5 and 6 for each zone in your system, working your way towards the zone closest to the air compressor connection.
- Disconnect the Air Compressor: Once all zones are blown out, disconnect the air compressor.
- Leave Zone Valves Open (Optional): Some professionals recommend leaving the zone valves slightly open to allow for any remaining water to drain. Consult with an irrigation professional for advice specific to your area and system.
- Turn Off the Irrigation Controller: Ensure the controller is switched off to prevent accidental activation during the winter.
Air Compressor Settings & Pressure Considerations
The correct air pressure is critical for a successful blow-out. Too little pressure won’t remove all the water; too much pressure can damage the pipes and sprinkler heads.
| Pipe Material | Recommended Air Pressure (PSI) |
|---|---|
| PVC | 50-80 |
| Polyethylene | 30-50 |
Common Mistakes to Avoid
- Using Insufficient Air Pressure: Not using enough pressure can leave water in the lines.
- Exceeding Maximum Pressure Ratings: Using too much pressure can damage your system components.
- Not Blowing Out All Zones: Forgetting a zone can lead to freezing and damage.
- Using the Wrong Fittings: Using the wrong fittings can result in leaks and inefficient blow-out.
- Ignoring Safety Precautions: Always wear safety glasses.
- Failing to Turn Off the Water Supply: This can lead to backflow into your water source.
Frequently Asked Questions (FAQs)
What CFM (Cubic Feet per Minute) air compressor do I need?
The required CFM depends on the size and complexity of your irrigation system. A minimum of 15 CFM is generally recommended for residential systems, but larger systems may require 25 CFM or more. Consulting a local irrigation professional is the best way to determine the appropriate CFM for your specific needs.
How long should I blow out each zone?
The blow-out time depends on the length and diameter of the pipes in each zone. Typically, 2-3 minutes per zone is sufficient, but longer zones may require more time. Continue blowing out each zone until only a fine mist or no water emerges from the sprinkler heads.
Can I use a leaf blower to blow out my irrigation system?
While some people attempt to use leaf blowers, it’s generally not recommended. Leaf blowers typically don’t provide sufficient air pressure to effectively remove all the water from the system, leaving it vulnerable to freezing damage. An air compressor is the preferred method.
What if I don’t have an air compressor?
If you don’t have an air compressor, you can hire a professional irrigation company to blow out your system. This is the safest and most effective option.
What happens if I forget to blow out my irrigation system?
If you forget to blow out your irrigation system and the temperature drops below freezing, the water in the pipes can freeze and expand, causing cracks and breaks in the pipes, valves, and sprinkler heads. This can result in costly repairs in the spring.
How can I protect my backflow preventer from freezing?
Insulate your backflow preventer with insulation foam or blankets to protect it from freezing temperatures. You can also wrap it with heat tape, but be careful not to overheat it.
What if I have drip irrigation?
Drip irrigation systems can be more challenging to blow out due to the small diameter of the tubing. Reduce the air pressure and blow out each zone for a longer period. Consider manually removing the end caps of the drip lines to allow for better drainage.
Is it okay to leave the controller on during the winter?
It is recommended to turn off the irrigation controller during the winter to prevent accidental activation. This will also save energy.
What do I do if water keeps coming out of the sprinkler heads even after blowing out the zone for a long time?
This could indicate a leak in the zone or insufficient air pressure. Check for leaks and ensure the air compressor is providing adequate pressure. If the problem persists, consult with an irrigation professional.
How often should I winterize my irrigation system?
You should winterize your irrigation system every year before the first hard freeze.
What is the best time of day to blow out my irrigation system?
The best time of day is when the temperature is above freezing and there is no rain or snow.
Can I damage my pipes by blowing them out?
Yes, using excessive air pressure can damage your pipes. Always start with a low pressure and gradually increase it if necessary. Never exceed the maximum pressure rating of your system components.
This guide provides a detailed overview of how to blow out an irrigation system. By following these steps and taking the necessary precautions, you can protect your irrigation system from freezing damage and ensure its longevity.