How to Prepare Your House Before You Leave for a Long Trip
Why this matters
An empty house cannot notice anything. A washing machine hose that splits while you are home is a wet floor and a towel. The same hose splitting the day after you leave runs until somebody walks in. Say a failed supply line flows 5 gallons a minute, an illustrative figure: that is 300 gallons an hour and 7,200 gallons a day, and over a long weekend that is enough to put a few feet of water across a typical basement floor. Most of what goes wrong in an empty house comes from two things, water that is still pressurized and heat that stops. The preparation below takes about an hour, and nearly all of it is about those two.
Winter trips need the most care, because the two problems combine. A furnace that quits on a cold night lets pipes freeze, a frozen pipe splits, and the split only leaks once it thaws, often days later. If you will be gone in freezing weather, every step here matters, and the person checking on the house becomes part of the plan.
Step 1: Decide what kind of trip this is
Write down three things before you start: how long you will be away, the lowest outdoor temperature likely while you are gone, and whether anyone will be inside the house during that time. A four-day trip in May and a three-week trip in January get different answers on the thermostat, the water heater and how often someone needs to look in. Everything below says where the answer changes.
Step 2: Test the sump pump and the alarms, while you still have water
Do this before you close any water valves, because the sump test needs a bucket of water.
- Sump pump: slowly pour water into the pit until the float lifts and the pump starts, empties the pit and shuts off. If it does not start, hums without pumping, or runs and does not stop, call a plumber before you leave. Do not reach into the pit or handle the pump with it plugged in. See related: How to Test Your Sump Pump Before Storm Season.
- Smoke and carbon monoxide alarms: press the test button on each one and replace weak batteries. See related: How to Test Your Smoke and Carbon Monoxide Alarms.
- A freeze or leak alarm, if you have one, that sends a phone alert: confirm it still reports and that the internet connection it relies on will stay powered.
If you skip it: you find out the sump pump had failed when you come home to the rainstorm that happened while you were gone.
Step 3: Set the thermostat to a safe holding temperature
In cold weather, keep the heat on. A common recommendation is not to set it below 55 F. Pipes in exterior walls, under sinks on outside walls and in unheated corners run colder than the thermostat reads, which is why the holding temperature sits well above freezing rather than just over it. Many people choose a few degrees higher for an older or drafty house.
Open the cabinet doors under sinks on exterior walls so room air can reach those pipes. Make sure the thermostat has fresh batteries if it uses them.
In hot weather, raise the cooling setting rather than turning it off, commonly to around 80 to 85 F. In a humid climate, an air conditioner that never runs lets indoor humidity climb, and a closed-up house can grow mold in a few weeks.
If you have a heat pump, leave it in its normal heating mode at the holding temperature. Do not switch it to emergency heat. See related: What Your Thermostat Settings Actually Do.
Step 4: Put the water heater in vacation mode, where it has one
Many gas tank heaters have a "vacation" setting on the gas control, which keeps the pilot or the control on but holds the water at a low temperature. Many electric, heat pump and tankless heaters have a vacation or away mode on their display. Your heater's manual says which yours has.
If yours has no vacation mode, leave it as it is. Do not turn a gas control to off unless you know how to relight it safely and the manual says you may, and do not switch an electric heater's breaker off and on without a reason. Never let anyone run an electric water heater with its tank empty. See related: Living with Your New Water Heater.
Step 5: Close the main water valve
This is the single most protective step. With the main closed, a split hose or a failed fitting can only release the water already sitting in the pipes, a few gallons, rather than everything the city or the well can supply.
- Turn off the refrigerator's ice maker, so it does not keep calling for water that is not there.
- Close the main water valve. See related: How to Close Your Main Water Valve and Fixture Stops, and Your Home's Shutoffs: Water, Gas and Electric.
- Open the kitchen faucet. The flow should slow to a trickle and stop within a few seconds. Close the faucet. If water keeps running steadily, the valve is not fully closed or is not holding; call a plumber rather than forcing it.
If you cannot close the main, because the valve is stuck, broken or out of reach, at least close the fixture stops: the two valves behind the washing machine, the valve behind each toilet, and the stop under the refrigerator if it has a water line. Those cover the most common failures, but they leave the pipes themselves under pressure.
Before you close the main, check two exceptions.
- A home fire sprinkler system may be fed from the same supply as the house. If yours is, closing the main also shuts off the sprinklers. Close the fixture stops instead, and ask the sprinkler contractor or a plumber whether the system has its own valve.
- A boiler heating system often refills itself from the house water. Ask your heating contractor before you close the main for a winter trip, since some setups need that supply and others have their own valve.
Step 6: Unplug what does not need power
Unplug televisions, computers, chargers, the coffee maker, the toaster, space heaters and anything with a power brick. That protects them from a lightning surge and removes any small chance of a fault while nobody is home.
Leave these plugged in: the refrigerator and freezer, the sump pump, the furnace or heat pump, the water heater, any medical equipment that has to stay charged, the security system, and the internet router if your thermostat, cameras or leak alarms depend on it.
Step 7: Ask someone to check inside
A person who walks through the house is the only thing that catches what alarms do not. Give them a key, the alarm code, your contact information, and the number of the shops you use.
Show them, before you leave:
- Where the main water valve is and how it closes, in case they find water anyway.
- What the thermostat should read.
- Where the sump pit is, and what a running pump sounds like.
For a winter trip, ask them to come every two or three days, look at the thermostat, walk the basement and look up at ceilings under bathrooms, and listen for the furnace. For a summer trip, once a week is usually enough.
Check your homeowner's policy. Many policies limit coverage for freeze damage in a house left without heat, or one left unoccupied past a stated number of days, unless heat was kept on or the water was shut off and drained. Ask your agent what yours says before you go.
A worked example: three weeks away in January
The house: two stories, a basement with a sump pump, a gas furnace, a gas tank water heater, city water. The trip: 22 days in January, with forecast lows near 10 F. A neighbor agreed to check in.
LEAVING 01/08 - BACK 01/30 (22 days)
lows near 10 F, neighbor checks
01/07 evening
[x] Sump: 2 buckets in, pump ran 20 s,
shut off. Pit dry.
[x] Smoke + CO: all 6 tested, 2
batteries replaced
[x] Thermostat: heat, hold 58 F
(new batteries)
[x] Sink cabinets open: kitchen, both
baths (exterior walls)
[x] Unplugged: TVs, PCs, chargers,
coffee maker
[x] Left on: fridge, freezer, sump,
router, furnace, water heater
01/08 morning
[x] Ice maker off
[x] Water heater: gas control to VAC
[x] Main closed (basement, front wall)
[x] Kitchen tap: stopped in ~5 s, closed
NEIGHBOR: every 2 to 3 days. Shown
main valve, thermostat, sump.
Why this order. The sump test came first, the evening before, because it needed two buckets of water and the main was not closed until the morning of departure. The ice maker went off before the main was closed, not after. The water heater went to its vacation setting because the house would use no hot water for three weeks.
Why 58 F and not 55 F. The house has a bathroom over an unheated garage, and its pipes run in that floor. With lows near 10 F, the owners added 3 degrees over the common 55 F floor for that cold corner, and opened that bathroom's cabinet as well.
What happened. On day 9 the neighbor found the house at 51 F, below the 58 F setting, and the furnace not running. Because the thermostat was the first thing on the list, it was noticed on that visit, not a week later. The neighbor called the heating contractor, who found a failed ignitor and had heat back that afternoon. No pipes froze. With the main closed, even a split pipe would have released only the water left in the lines.
What would have changed it. The same trip in July: thermostat raised to cooling at 82 F rather than set for heat, no cabinet doors opened, the neighbor once a week instead of every two to three days, and the main still closed, because a washer hose splits in any season.
Coming home
Open the main slowly, about a quarter turn at first, and listen for running water anywhere in the house before opening it fully. Run each faucet until the air sputter clears. Turn the ice maker back on, return the water heater to its normal setting, and set the thermostat back. Walk the basement and look at the ceilings once more.
References
- See related: Your Home's Shutoffs: Water, Gas and Electric
- See related: How to Close Your Main Water Valve and Fixture Stops
- See related: How to Test Your Sump Pump Before Storm Season
- See related: Frozen Pipe Prevention + Thaw Reference
- See related: Teaching Seasonal Habits That Prevent Emergencies