Quick Answer:
If your outdoor spigot is pushing water back into the indoor lines, first check simple causes: check hose elevation, disconnect and see if backflow stops. If removing the hose or raising it stops the reverse flow, the problem is likely the hose or a pressure issue. If the backflow continues with the hose off, shut the outdoor valve (or the main) and get professional help.
Why This Happens
Water moves from higher pressure to lower pressure. If an outdoor hose or connected device sits lower than the spigot or is connected to a pressurized irrigation source, it can create a path that pushes water back toward interior plumbing. Valves that don’t seat properly, a missing or failed backflow preventer, or shared piping for irrigation and house supply can also let water flow the wrong way.
This problem can show up alongside other spigot issues, such as Outdoor Spigot Knocks Pipes Inside the Wall or when you notice air and sputtering before steady flow.
Step-by-Step What to Do
Step 1 — Stop the obvious flow
- Close the outdoor spigot fully and any local shutoff for that spigot if you have one.
- If closing the spigot doesn’t stop water moving inside, shut off the house main to prevent damage and use the next steps to diagnose safely.
Step 2 — Check hose elevation
- Raise the hose so it slopes away from the spigot and any low areas. Low, puddled hoses can let water run back toward the house if pressure shifts.
- If the reverse flow stops when the hose is raised, reroute or loop the hose higher to prevent recurrence.
Step 3 — Disconnect and test
- Disconnect the hose from the spigot. Observe whether the backflow into the house stops with the hose removed.
- If disconnecting the hose stops the problem, the hose, nozzle, or an attached device is likely the cause. Repair or replace those items and test again.
Step 4 — Inspect valves and devices
- Look for a failed vacuum breaker or missing backflow preventer on the spigot. These devices are small and often attached right at the spigot outlet.
- Check indoor shutoffs that control the spigot feed. If a valve inside the house is open or leaking, it can allow unwanted flow paths.
Step 5 — If it continues, isolate and call
- If backflow continues with the hose removed and local shutoffs closed, leave the main shutoff off and contact a plumber. Persistent backflow can mean a cross-connection or failed internal valve that needs professional repair.
What Not to Do
- Do not rely on backflow through hoses as a fix or test — hoses are not designed to stop or control pressure problems.
- Do not force fittings or try to repair pressurized components without shutting water off first.
- Do not ignore water appearing inside walls or cabinets; hidden leaks can cause mold and structural damage.
When to Call a Professional
- If backflow continues after the hose is disconnected and valves are closed.
- If you see water inside walls, ceilings, or persistent low pressure in the house.
- If you’re unsure how your irrigation and house lines are connected, or if a backflow preventer is missing or seems faulty.
Safety Notes
- Before disconnecting anything, turn off the spigot and relieve pressure by opening an indoor faucet.
- Wear gloves and eye protection when working with valves and fittings.
- Do not use open flame or aggressive tools on frozen or pressurized pipes; call a pro for frozen-pipe issues.
- If you shut off the house main, know where the water meter or main shutoff is and how to turn it back on safely.
Common Homeowner Questions
- Can a hose actually push water back into my house? Yes — if it’s routed downhill, connected to another pressurized source, or creates a cross-connection.
- Is this an emergency? It can be. If water enters living spaces or the problem continues with the hose removed, act quickly and consider shutting off the main.
- Will adding a backflow preventer fix it? Often yes — a properly installed backflow preventer at the spigot or meter stops reverse flow, but a plumber should confirm the correct device and location.
If you notice air or sputtering before steady flow, check related troubleshooting like Outdoor Spigot Sprays Air Before Water for additional clues.