A power outage is a minor annoyance when you’re home and a real problem when you’re 1,000 miles away and can’t open the fridge, check the basement, or nudge the thermostat. The same blackout that means “light a candle” while you’re there can mean burst pipes, a flooded basement, or a freezer full of spoiled food while you’re gone. The good news: most of that risk is preventable with a short checklist before you leave and a couple of inexpensive backups.
What actually goes wrong when the power fails while you’re away
When you’re in the house, an outage is mostly an inconvenience because you’re there to react. You move food to a cooler, you notice water on the floor, you keep the place warm. Take the person out of the house and every one of those small fixes disappears. The outage runs for hours or days with nobody watching, and the damage compounds.
The four risks worth planning around are: frozen and burst pipes if the heat dies in winter, food spoilage in the fridge and freezer, basement flooding if your sump pump loses power during a storm, and a dark, unmonitored house from a security standpoint. There are also narrower concerns like medical devices left charging, refrigerated medication, and aquariums. Each one has a cheap mitigation, and most come down to either a backup power source or a person you trust with a key.
Frozen and burst pipes: the most expensive winter risk
If you’re traveling in cold weather and the furnace shuts off with the power, indoor temperatures can drop below freezing within hours. Water in the pipes expands as it freezes, and a burst pipe can flood a home for days before anyone notices. This is the single most costly thing on this list, and it’s also the most preventable.
The American Red Cross recommends that if you’re going away during cold weather, you leave the heat on, set no lower than 55°F. That keeps the building envelope warm enough to protect the plumbing if power returns or never fully drops. But heat only helps if the power stays on. For a longer trip, or anytime an extended outage is realistic, the more reliable move is to shut off the main water supply and drain the system: close the main shut-off valve, turn off the water heater, and open indoor and outdoor faucets to drain the pipes. With no water in the lines, there’s nothing to freeze and burst.
If you can’t fully winterize, the practical compromise is to keep the heat at a safe minimum, open cabinet doors under sinks so warm air reaches the pipes, and have a neighbor check the house. Make sure you and at least one other person know where the main shut-off valve is, so a burst pipe can be stopped fast. For the full cold-weather routine, see our guide on how to winterize your home for power outages.
Food in the fridge and freezer: what survives and what doesn’t
You won’t be there to move food to a cooler, so the question becomes: how long will the appliances hold, and how will you know if they failed? The USDA’s numbers are the ones to trust. A closed refrigerator keeps food safe for about 4 hours. A full freezer holds a safe temperature for about 48 hours, or about 24 hours if it’s only half full, as long as the door stays shut. A full freezer is your friend here: it holds cold far longer, so filling empty space with water jugs before a long trip genuinely helps.
The hard part when you’re away is knowing whether the freezer thawed and refroze while you were gone. The widely shared trick: freeze a cup of water solid, set a coin on top of the ice, and leave it in the freezer. If you come home and the coin is still on the surface, the freezer stayed frozen. If the coin has sunk to the bottom, the contents thawed and refroze, and you should treat the food as suspect. It’s a rough indicator, not a guarantee, but it’s better than guessing. A simple appliance thermometer left in the freezer is more precise: if it reads 40°F or below when you return, the food is safe and can be refrozen.
When you do get home, the USDA rule is simple and conservative: discard any perishable food (meat, poultry, fish, eggs, leftovers) that’s been above 40°F for two hours or more, and never taste food to check it. When in doubt, throw it out. We cover the details in is food safe after a power outage and how long a freezer lasts without power.
Sump pump failure and basement flooding
If your home relies on a sump pump, an outage during a storm is the worst-case timing. Heavy rain raises the water table at exactly the moment the pump loses power, and the pit overflows into the basement. Nobody’s home to bail it out, so a few inches becomes a flooded finished basement.
The standard fix is a battery backup sump pump that switches on automatically when the primary pump loses power. It runs on its own battery, activates without you flipping any switches, and many models send a phone alert or sound an alarm when they kick in. It’s meant to run alongside your main pump, not replace it. If you’d rather power the existing pump from a portable battery instead, size it carefully, because pumps draw a big surge when the motor starts. Our guide on what size power station for a sump pump walks through the math. Either way, test the backup before you leave, not after the basement floods.
Security, lighting, and the smart-home trap
A dark house with no exterior lights signals that nobody’s home. The reflex is to lean on smart-home gear, but an outage exposes its weak point: smart cameras, video doorbells, and Wi-Fi alarms all need power and internet to do anything. When the grid drops, your router dies, and so does every alert you were counting on. If you only learn about the outage because your camera stopped responding, that’s not much of a warning.
Build in some independence from the grid. Battery-powered or solar motion lights keep the exterior lit without mains power. A small uninterruptible power supply (UPS) on your router and modem can keep internet alive long enough for smart-home alerts to fire and for a backup pump or sensor to phone home. A battery-backed water sensor on the basement floor, or a smart plug that texts you when it loses power, turns a silent failure into an early warning. None of this is expensive, and it’s the difference between finding out now versus finding out when you walk through the door.
Medical devices, refrigerated medication, and aquariums
If anyone in the household depends on a powered medical device, or you store refrigerated medication like insulin, an extended outage while you’re away needs its own plan. A fridge that loses power for many hours may not keep medication within its safe range, so check the manufacturer’s guidance and consider a backup cooling plan or a trusted person to move it. Aquariums and reptile tanks are easy to forget: filtration and heating stop, and fish can’t wait days. A battery air pump, a generator, or simply a neighbor with instructions can bridge a short outage.
For any of these, the most reliable backup is still a person. Give a neighbor or family member a key, your contact number, and clear instructions on what to check and who to call. A battery is only as good as its runtime; a human can adapt.
Before-you-leave checklist
- Set the heat (winter): Leave it on, no lower than 55°F. For longer trips, shut off the main water and drain the pipes instead.
- Locate the main water shut-off: Know where it is, and make sure your neighbor does too.
- Fill the freezer: Use water jugs to fill empty space so it holds cold longer. Add a freezer thermometer and the coin-on-ice indicator.
- Eat down the fridge: Use up or freeze the most perishable items before you go so there’s less to lose.
- Test the sump pump backup: Confirm the battery backup works and the alarm or app alert is on.
- Cover security and lighting: Set battery or solar exterior lights; put a UPS on the router so alerts can still fire.
- Add a notifier: A smart plug or sensor that texts you when power drops turns a silent outage into an early warning.
- Handle medical and pets: Plan for refrigerated medication, powered devices, and aquariums; arrange a backup or a person.
- Brief a neighbor: Leave a key, your number, and a short list of what to check and who to call.
- Note the utility’s outage line: Leave your account number and the power company’s number with whoever’s checking the house.
If you want a broader walkthrough that isn’t specific to travel, our guides on how to prepare your home for a power outage and the power outage emergency kit checklist cover the rest of the household.
Frequently asked questions
How do I know if the power went out while I was on vacation?
A smart plug or power monitor that sends a phone notification when it loses power is the simplest method, though it relies on your internet staying up. The low-tech version is the coin-on-a-cup-of-ice trick in the freezer: if the coin has sunk, the freezer thawed at some point. A neighbor checking the house is the most reliable signal of all.
Should I shut off the water before leaving for a winter trip?
For an extended trip in freezing weather, yes. Shutting off the main valve, turning off the water heater, and draining the faucets removes the water that could freeze and burst a pipe. For a short trip, leaving the heat set no lower than 55°F is the Red Cross-recommended minimum, but it only protects you if the power stays on.
Is food safe to eat after the power was out while I was away?
Refrigerated perishables are safe only if power was out for under about 4 hours, which is hard to confirm after a long absence, so treat fridge food as suspect. Frozen food can be refrozen if it still has ice crystals or read 40°F or below. Discard anything that was above 40°F for two hours or more, and never taste-test. When in doubt, throw it out.
Will a full freezer really keep food cold longer than a half-empty one?
Yes. The USDA says a full freezer holds a safe temperature for about 48 hours with the door closed, versus about 24 hours when half full. Frozen mass acts as its own cold reserve, so filling empty space with jugs of water before a trip meaningfully extends how long food stays safe.
Do my smart cameras and alarm work during an outage?
Only as long as they have power and internet. Most cameras, video doorbells, and Wi-Fi alarms go dark when the grid drops because the router loses power. A small UPS on your modem and router keeps them online for a while; battery or solar exterior lights and a battery-backed sensor give you coverage that doesn’t depend on the grid at all.