Having a frozen sprinkler system can be a huge headache. Not only does it prevent your system from properly watering your lawn or landscaping, but it can also lead to busted pipes and costly repairs. The best way to prevent frozen pipes and malfunctioning sprinklers is to install automatic drain valves in your system. Follow this guide to learn everything you need to know about choosing, installing, and maintaining automatic drain valves for your sprinkler system.
What are Automatic Drain Valves?
Automatic drain valves, also called automatic blowout valves, are devices designed to automatically drain water from your sprinkler system before the first freeze of the winter season.
Here’s how they work:
- The valve is installed at the lowest point(s) in your sprinkler system. This allows gravity to drain the water out of the pipes.
- Near the beginning of winter, you manually open the valve to allow any remaining water to drain out of the system.
- When the outdoor temperature drops to near freezing, the automatic valve opens. This drains any last bit of water from the pipes to prevent freezing and pipe burst.
- In the spring, you manually close the valve so the system can pressurize again.
Installing automatic drain valves is crucial if you live in an area with freezing winter temperatures. They provide a convenient, reliable way to winterize your system with minimal effort.
Benefits of Installing Automatic Drain Valves
There are several key reasons why installing automatic drain valves is highly recommended:
Prevents Pipe Bursts
The #1 benefit is that automatic valves prevent frozen and ruptured pipes. When water freezes inside pipes, it expands in volume and causes enough force to break the pipes. This leads to costly repairs and water damage. Automatic drain valves remove water so it can’t freeze and expand inside the system.
Saves Time
Draining your sprinkler system manually can take hours of labor. Automatic drain valves do this for you with no effort required. Once installed and opened for the winter, they take care of the rest.
Convenient and Reliable
You don’t have to monitor weather forecasts or outdoor temperatures to know when you need to drain your system. The automatic valve does this for you when the temperature hits the preset threshold, usually around 38°F.
Extends Life of System
Regular winterization saves wear and tear on your pipes and sprinkler heads. It helps prevent damage from freeze/thaw cycles. This extends the life of your entire irrigation system.
Reduces Damage Risk
Forgetful homeowners often neglect to manually winterize their systems. Automatic drain valves remove the risk of human error and make sure your system gets properly winterized before freeze.
Provides Peace of Mind
Once installed, you can relax knowing your sprinkler system will be protected without any additional effort on your part. The valves drain the system automatically based on temperature.
Choosing the Right Automatic Drain Valve
If you’ve decided to install automatic drain valves, the next step is choosing the right products. Here are the key factors to consider:
Freeze Resistance Rating
Check the valve’s freeze resistance rating, measured in degrees Fahrenheit. Most automatic drain valves are rated to open when the outdoor temperature hits around 38°F. This rating should be suitable for most climates. Colder regions may require a lower rating.
Flow Rate
Match the valve’s flow rate capacity to the size of your sprinkler system. The valve must be able to quickly drain the system before freezing occurs. This spec is measured in gallons per minute (GPM).
Number of Valves
Determine how many automatic drain valves your system requires based on the layout. Install one at each section or zone that holds water when not in use. Most residential systems only need one valve at the lowest point.
Compatible Materials
Ensure the valve materials are compatible with the pipes in your sprinkler system to prevent corrosion. Common materials include brass, plastic, and stainless steel.
Quality and Durability
Choose valves from reputable brands that are built to last. Look for robust housings and durable internal seals and components. Pay a little more for higher quality that will provide years of reliable service.
Cost
Automatic drain valves range in price from $20 on the low end to $60+ for heavy-duty commercial models. In most standard residential systems, a mid-range option for $40-50 is ideal.
Ease of Installation
Consider whether you want to DIY the installation or hire a pro. Opt for an automatic valve designed for straightforward DIY fitting like compression or threaded models. Or choose a convenient union valve that connects without tools.
Manual Override
Many automatic drain valves also provide the option to manually hold the valve open or closed as needed for seasonal maintenance. This provides added flexibility.
By carefully choosing the right automatic drain valve for your sprinkler system, you can ensure reliable, hassle-free winterization for years to come. Contact your local irrigation supply store for help selecting suitable options.
How to Install Automatic Drain Valves
Once you’ve purchased the right automatic drain valve(s) for your system, it’s time to install them. Here are step-by-step instructions for properly fitting your new valves:
Gather Tools and Materials
You will need:
- Automatic drain valve(s)
- Shovel for digging (if burying valves)
- Pliers
- Pipe wrenches
- Teflon tape
- Adjustable wrench
- Hacksaw (if cutting pipe)
- Sandpaper
Turn Off Water Supply
Locate the main shutoff valve for your sprinkler system and turn off the water supply. This is necessary for a safe installation.
Choose Installation Site
Decide where you will install the automatic valve. This is typically at the lowest point of the irrigation system. Often it is near the backflow preventer device.
Dig Hole If Burying Valve
If you will be burying the valve underground, dig a hole approximately 12 inches deep. It should be near the planned installation site on the water supply line.
Cut Pipe
Measure and mark the pipe where you need to install the valve. Use a hacksaw to cut the pipe at this mark. Sand the cut edges smooth.
Deburr and Prep Pipes
Use sandpaper or a metal file to deburr and smooth the interior and exterior of the cut pipe ends. This allows for leak-free valve installation. Also clean the valve inlet and outlet.
Apply Teflon Tape
Wrap the pipe threads evenly in 2-3 layers of Teflon tape. This prevents leaks at the threaded connections. Take care not to cover the first thread to avoid damaging tape.
Screw on Valve Connection
Hand tighten the automatic drain valve onto the prepared pipe end threads. Use pliers or a wrench to tighten further but take care not to over-tighten.
Attach Outlet Side
Attach a short length of pipe to the outlet side of the automatic valve using the same threading technique. Extend this to discharge away from the valve box or building foundation.
Test for Leaks
Slowly turn water supply back on and inspect carefully for leaks at connections. Tighten joints or reapply tape if necessary to stop leaks.
Open Valve and Flush System
Once leak-free, open the automatic valve using the bleed or manual override. Flush and pressurize the system to wash out any debris dislodged during installation.
Finish and Close Valve
Bury underground valves in holes and backfill with soil. Close the automatic valve and return system to normal operation. Your valve is now installed!
Be sure to test that your automatic drain valves activate and drain properly when winterizing your system for the first time. Schedule annual inspections to ensure they continue functioning properly.
Maintaining Your Automatic Drain Valves
Automatic drain valves are built for long-lasting performance. But like any system component, they require periodic maintenance for optimal results. Follow these tips:
Flush Debris Before Winter
Thoroughly flush the sprinkler system in fall to wash away mineral deposits and debris. This prevents buildup from fouling the automatic valves.
Inspect Annually
Check valves yearly for signs of wear, corrosion, damage, or leaks that could impact performance. Repair or replace worn valves.
Confirm Winter Activation
Manually test that valves open and fully drain as expected when temperatures drop in late fall. Adjust to activate earlier or later if needed.
Replace Internal Seals
Internal seals and o-rings wear over time. Replace old seals with new to prevent leaks and ensure valves open/close airtight.
Check for Proper Closure
In spring, confirm valves fully close again when it’s time to re-pressurize your system for the new watering season.
Keep Valve Box Accessible
For underground automatic drain valves, ensure the valve box remains accessible and not buried or obstructed by mulch/debris.
Lubricate Threads and Seals
Apply plumbers grease or lubricant to o-rings and threads. This prevents binding and allows smooth operation when opening/closing valves.
Clear Any Obstructions
Check for and remove pebbles, sticks, mud or other material that could obstruct the automatic valve mechanism and prevent it from draining properly.
With periodic maintenance and testing, your automatic drain valves will provide years of reliable service and serious peace of mind! Installing them is one of the best ways to protect your sprinkler system from freeze damage.
Frequently Asked Questions
How do I manually open and close the valves?
Most automatic drain valves have a bleed or manual override that allows you to manually hold the valve open or closed. Simply turn or slide the override lever to the desired position.
Where should I install valves in the sprinkler system?
Install automatic drain valves at the lowest point(s) in your sprinkler system. They must be positioned to allow total drainage via gravity flow when opened.
What temperature should automatic drain valves activate at?
The valves should be preset to open when temperatures hit 38 to 40°F. This gives a buffer before the freezing point of 32°F. Adjust earlier or later as needed for your local climate.
Do I need one valve for each zone in my system?
Most residential systems only require one automatic drain valve located at the lowest point. Larger systems with separate zones may need a valve at each zone’s low point.
How do I prevent debris from fouling the valves?
Thoroughly flushing debris from the system in fall is key. Also install a mesh screen filter upstream of the valve to catch any particles.
Can I install automatic drain valves myself?
YES! Automatic drain valves are designed for easy DIY installation. Make sure to follow all instructions carefully, especially proper pipe preparation.
How often should I maintain my automatic drain valves?
Inspect valves at least annually. Check operation and seals, lubricate, and replace any worn parts to ensure they function properly each winter.
My valve is leaking. How do I fix this?
Check that pipe joints are properly threaded. Rinse debris from valve seat. Replace worn o-rings or other seals if leaks between sections. Tighten components securely.
Conclusion
Installing automatic drain valves is one of the best ways to keep your sprinkler system protected from freeze damage. By following this guide, you can choose the right valve for your system, install it properly, and keep it maintained for years of reliable wintertime drainage. Make automatic drain valves part of your seasonal maintenance routine to prevent costly repairs from frozen and burst pipes!