An anti-siphon spigot, also known as a non-siphon or vacuum breaker spigot, is a type of outdoor spigot designed to prevent backflow and contamination of the water supply. If your anti-siphon spigot is leaking or not functioning properly, there are several steps you can take to try and fix it yourself before calling a plumber. In this article, we’ll go over the common issues that can occur with anti-siphon spigots and how to troubleshoot and repair them.
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What is an Anti-Siphon Spigot?
An anti-siphon spigot contains a vacuum breaker assembly that sits near the opening of the spigot. This assembly has a floating disc inside that gets pulled up to allow water to flow out of the spigot when the handle is turned on. When the water is shut off, the disc drops back down and seats against the opening, sealing off the water supply.
The key function of this mechanism is that it prevents backflow and back-siphonage from occurring. Backflow is when water flows in the opposite direction from its normal flow. Back-siphonage occurs when a negative pressure in the downstream plumbing sucks water back into the supply plumbing from a source that may be contaminated.
The anti-siphon spigot is an important safety device for outdoor spigots where hoses and attachments are used that could cause backflow. Things like fertilizer applicators, pressure washers, and submerged hoses can all potentially contaminate your home’s water supply if backflow occurs. The anti-siphon spigot prevents this.
Common Issues with Anti-Siphon Spigots
There are several common problems that can occur with anti-siphon spigots:
Continuous Leaking from Spigot
A small drip or leak when the spigot is off is usually caused by a worn out rubber washer inside the spigot assembly. Replacing this washer should stop the leak.
A more significant, continuous leak likely indicates an issue with the vacuum breaker or check valve components inside the spigot. Dirt, debris, and mineral deposits can prevent these parts from sealing properly.
Spigot Won’t Turn On
If no water comes out when you turn the handle on, several things could cause this:
– Closed supply valve – Check that the shutoff valve inside your house supplying the spigot is open.
– Frozen water line – Outdoor spigots can freeze in winter. You may need to thaw the line.
– Broken handle – The spigot handle may be broken internally. Try removing the handle and turning the stem directly with pliers.
– Vacuum breaker stuck – Mineral deposits or debris could be preventing the vacuum breaker from rising up to allow water flow.
– Internal parts failure – Internal seals, springs or washers may be too worn out or broken.
Water Leaking from Vacuum Breaker
If you see water dripping or spraying out of the vacuum breaker itself when the spigot is on, this indicates failure of the vacuum breaker seals. The floating disk is not dropping back down to seat properly when water is shut off. The vacuum breaker assembly will need to be repaired or replaced.
No Backflow Prevention
If you notice the spigot is allowing backflow and back-siphonage to occur, the internal check valves and vacuum breaker are not functioning. This can allow contaminants to enter your water pipes. Replace the faulty anti-siphon unit.
How to Repair an Anti-Siphon Spigot
If you’re experiencing any of the above issues, here are the steps to troubleshoot and repair an anti-siphon spigot:
Materials Needed
– Adjustable wrenches
– Replacement rubber washer
– Spigot rebuild kit or new anti-siphon vacuum breaker
– Pipe sealant/PTFE plumber’s tape
– Rag
– Vinegar or calcium-lime-rust remover
Shut Off Water Supply
Begin by locating the shutoff valve for the spigot inside your home (often in the basement or crawlspace) and turning it clockwise to shut off the water. Open the spigot to release pressure and drain any remaining water from the line.
Remove Spigot Handle and Access Internal Parts
Use an adjustable wrench to loosen and remove the spigot handle. This will expose the valve stem and allow you to access the internal components.
Assess Issue and Perform Needed Repairs
Inspect the parts for wear, mineral deposits, rust, and debris. Try flushing the line with vinegar to clear any buildup. Refer to the steps below based on the specific issue:
Leaky Washer: Replace the small rubber washer on the valve stem. Apply pipe sealant to the new washer before installing.
Vacuum Breaker Leaking: The full vacuum breaker assembly will likely need replacement. Unthread the broken unit and replace with a new vacuum breaker, using pipe sealant on the threads.
Parts Not Sealing: Replace any visibly worn out or damaged internal seals, springs, and washers using the spigot rebuild kit parts. Take care to reassemble properly.
Handle or Stem Broken: Replace broken parts. The entire spigot body may need replacement if damage is excessive.
Reinstall Spigot Components
Once any necessary repairs or part replacements are complete, reassemble the spigot. Make sure all internal pieces align correctly and thread the spigot body back together using pipe sealant on the threads.
Reattach the handle and turn the water supply back on slowly while checking for leaks. If leaks persist, further disassembly and replacement of parts may be needed. Give the spigot a test run to check water flow and backflow prevention.
When to Call a Professional
While many issues can be repaired DIY, some instances may require calling a plumber:
– The spigot or water lines are severely corroded and need replacement.
– No water flow despite repairs (indicates larger issue).
– Persistent leaking from the spigot body threads.
– The water supply line or shutoff valve replacement is needed.
– You’re unable to remove stuck or corroded internal spigot parts.
– There are signs of damage/cracks in the spigot body.
Plumbers have specialized tools and expertise to fully diagnose problems and replace damaged plumbing components. For major repairs, it is best to call a professional.
Preventing Future Problems
To help avoid issues and extend the life of your anti-siphon spigot:
– Inspect and flush spigots annually. Clear any debris or mineral buildup.
– Replace washers and seals regularly. Don’t wait for full failure.
– Disconnect hoses in winter to allow spigots to fully drain and prevent freezing.
– Apply lubricating oils or grease to keep parts moving freely.
– Use pipe sealant on all threaded connections.
– If spigot is leaking constantly, replace the valve. Don’t let parts corrode further.
– Install spigot freeze protection add-ons in cold climates.
– Consider installing insulated spigot covers in winter.
With proper maintenance and care, your anti-siphon spigot should provide years of trouble-free performance and help keep your home’s water supply clean and safe from contaminants.
Conclusion
Anti-siphon spigots contain important backflow prevention devices that can fail over time and need repair. Dripping leaks, an inability to turn on the water, and other issues are usually repairable with some basic tools and replacement parts. Inspecting washers, seals, vacuum breakers and internal components can reveal the problem. Following DIY troubleshooting and repair steps can restore proper spigot operation and prevent costly plumber service calls in many cases. But for any signs of major part failures or water line/valve issues, it is best to have a professional plumber handle the required repairs. With preventative maintenance and freeze protection in winter climates, anti-siphon spigots can be kept functioning properly for many years.