How to Prepare Your Plumbing Before Leaving for Vacation

Shut Off the Main Water Supply

For any trip longer than two or three days, the single most effective thing you can do is shut off the main water supply to the house before you leave. If a pipe connection fails, a supply hose to a washing machine bursts, or a toilet fill valve sticks open while you're gone, a main shut-off means the system is empty and no further water can damage your home.

Locate your main shut-off now — before you need it in a hurry. In most Redlands homes, it's at the street near the water meter in a covered ground box, or on the side of the house near the meter. The shut-off valve either requires a special tool (a meter key or water key, available at hardware stores) or is a simple gate or ball valve that turns by hand or with a wrench.

After shutting off the main, open the lowest faucet in the house — a laundry sink or hose bib — to drain the pressure from the lines. This prevents residual pressure from causing seepage at a weak connection while you're away.

Adjust Your Water Heater

With no one home, your water heater doesn't need to maintain a full-temperature tank. Most water heaters have a "vacation" setting on the thermostat — typically labeled "VAC" — that keeps the water just warm enough to prevent the pilot from going out and protect against Legionella growth (usually around 120°F) without maintaining full temperature.

For gas water heaters, setting to vacation mode is simple. For electric water heaters, you can switch the breaker to the heater off entirely if you've shut off the main water supply — an empty or low-usage tank doesn't need to stay energized. For tankless water heaters, the unit only fires on demand, so vacation mode isn't really necessary — but it's still sensible to confirm everything is in good order before leaving.

If you're shutting off the main water supply, you can also drain the water heater tank completely for long absences — this is good practice for trips of two weeks or more.

Fix Known Drips Before Leaving

Any dripping faucet, running toilet, or small leak that you've been tolerating becomes a much bigger concern when it runs unattended for a week or two. A toilet that runs intermittently and refills uses water continuously while you're away (even with the main on vacation mode if you choose not to shut off the main). A small leak under a sink soaks the cabinet and potentially the subfloor over two weeks.

Do a quick walkthrough of the house before leaving: check under every sink for any moisture or active drips, listen for a running toilet by checking the bowl for rippling, and address any fixture you know needs repair. A quick plumber visit before vacation is far less expensive than water damage remediation after.

Running the Fixtures Down

If you're shutting off the main water supply, run each fixture briefly before you leave to drain residual water from the supply lines. This prevents any remaining water from sitting stagnant in lines for the duration of your trip. It also gives you a chance to confirm that the main is fully off — if a fixture continues to flow after the main is shut off, the valve didn't seat fully or there's a second supply path you weren't aware of.

For toilets: flush once after shutting off the main to empty the tank. The bowl will remain filled (that's the trap, which is filled from the drain side, not the supply side) — which is correct.

In Redlands Heights during a warm summer, stagnant water in pipes with minimal insulation can also develop off-flavors. Flushing the lines when you return before drinking from the tap is a good habit.

Irrigation and Outdoor Plumbing

Outdoor plumbing deserves specific attention before a long absence. If you have a landscape irrigation system, confirm the controller is set correctly for weather patterns during your absence and that the rain shutoff sensor is functional. Irrigation timers that malfunction can run continuously — and an irrigation system running full cycle daily for two weeks while you're away is a significant water bill surprise.

Check hose bibs for any drip that might indicate a failing washer. Disconnect garden hoses from hose bibs — a hose connected to a bib can maintain back-pressure in the hose and contribute to connection wear. If you have any outdoor fixtures used seasonally, shut off the supply to those lines from inside the house if possible.

Leak Detectors and Shut-Off Devices

Smart water leak detectors have become affordable and genuinely useful. Small sensors placed under sinks, near the water heater, behind the refrigerator, and at the washing machine alert your phone if they detect moisture — giving you a chance to call a neighbor or property manager to take action before damage worsens.

More sophisticated whole-house water shutoff devices monitor flow through the main line and automatically shut off the water if they detect a flow pattern consistent with a leak. These are particularly valuable in Redlands Heights and similar hillside neighborhoods where a water leak can cause structural issues in addition to interior damage. They're an investment, but for homeowners who travel regularly, they provide meaningful protection.

If you're heading out and want a quick pre-vacation inspection — checking for any developing issues before you leave — call (207) 419-2600. We can do a focused plumbing check in under an hour.