With the harsh winter weather coming up fast, it is important to take some time to prepare your home for the elements. One preparation that is often overlooked by homeowners is preparing your sprinkler system for the cold weather. Doing so can help avoid damaged valves, seals, and pipes when warmer weather returns. Without proper winterizing, you may be faced with steep costs to repair any damages.
The most important thing to remember when winterizing your sprinkler system is that any water remaining in it must be blown out. Harsh winter temperatures can cause any water left behind to freeze and expand, resulting in damage to the metal and plastic components of the sprinkler system.
You will need an air compressor to prepare your system. You can rent an air compressor from an equipment rental company, hire a plumber who is qualified to perform this service or contact the company that initially installed the system and have them do it.
What You’ll Need
If you have an air compressor, you should have the following items to winterize your sprinkler system:
- Safety glasses for eye protection
- Your sprinkler system user manual in case you have any questions
- Metal fitting for the airline on the compressor
- Insulated blanket (if applicable)
- Stop and waste valve key (if applicable)
The first step in preparing your sprinkler system for winter is turning off the water supply to the system. Your shut-off valve will be in a valve box, which is typically found in your basement, garage, or another space that will protect it from freezing. Your shut-off valve could also be located up to five feet underground, and you will need a key to turn it off. It should not require much effort to turn your shut-off valve off; however, you do not want to force it and risk damage to the valve. Sprinkler systems that utilize a pump for the operation must be drained and disconnected. If possible, store your sprinkler system pump inside for the winter months. For pumps that are permanently in place, this is where you will need the insulated blanket to protect it from the elements.
The next step in the winterizing process is clearing out any water in the backflow device. If your sprinkler system operates on privately owned water, you will want to check the installation plan. Most sprinkler systems typically utilize public water sources and either have a pressure vacuum breaker (PVB) or an atmospheric vacuum breaker (AVB). You will find the AVB located below the valve, and it can be cleared out with the system. In contrast, you cannot use an air compressor to clear out a system with a PVB. For ones with PVBs, you will need to clear out the system first then rotate the test cocks and ball valves a few times. You will then want to position them half-open in order to avoid moisture from building up.
The third step in winterizing your sprinkler system is to actually clear the water out of the system. You will want to clear out all the water in the valves and downstream part of the system. While using the air compressor, it is recommended that you reach a range of 40-80 pounds/square inch. The following are recommendations based on the type of material of your sprinkler system:
- 50 pounds/square inch maximum for polyethylene pipe
- 80 pounds/square inch maximum for rigid PVC tubing
In order to find the best volume for your sprinkler system, simply take the gallons per minute and divide by 7.5, which will give you the cubic feet per minute of compressed air needed.
It is important to note that the size of your air compressor must be considered during this step. Large air compressors should be operated with a regulator to avoid clearing out the water too quickly and causing damage to the sprinkler system. Smaller air compressors can certainly be used for this step; it will just take longer to complete the process.
You will then need to hook up the air compressor to the blowout valve. Turn the compressor to the appropriate psi and begin running it. We recommend that you run the compressor two times for each zone of the sprinkler system.
The final step in the winterization process is to set all the valves on the backflow device to half-open. You will also want to keep the compressor controller plugged in since it is a source of heat to prevent condensation.
You have now successfully prepared your sprinkler system for the winter. Once the spring arrives, you will need to prepare your system for use again. You will need to ensure all valves are closed before re-pressurizing the system. Once the water flow is operational, you can then reopen the valves.
If you have any questions about this, or anything else related to landscaping, give us a call today!