How to Check an Anti-Siphon Valve

An anti-siphon valve is required in some areas' building codes for lawn irrigation systems. It is an important part of your plumbing for your health and safety, since without it some hazardous things could occur such as lawn chemicals backing up into your home's plumbing.

You will want to check from time to time to make sure your anti-siphon valve is operating properly; you can do this yourself without hiring a plumber.

Things You'll Need

• Plumber's wrench
• Shovel
• Teflon pipe tape

Instructions

1. Run the lawn sprinklers so that they fill with water then turn them off.

2. Turn off the main water supply at the pipe that is coming into the house.

3. Dig down to the piping that is behind the anti-siphon valve. Open the pipe behind the anti-siphon valve by unscrewing it with your plumber's wrench counterclockwise. If you have a basement hose connection, then open this up instead.

4. Remove the sprinkler head. Watch for water to flow out of the pipe that you opened. If there is water flowing, then your anti-siphon valve has failed. If there is none and water is still standing in the pipe that the sprinkler head attached to, then it is working properly.

5. Wrap teflon pipe tape two to three times around the threads of the pipe you opened and reattach the pipe by turning it clockwise with your plumber's wrench.