Should I turn my fridge or freezer off when I go away?

The saving is real but small: a fridge freezer costs roughly a pound a week to run, so a fortnight away is a couple of pounds. Against that sits a genuine risk of a mouldy cabinet, a ruined seal or a freezer full of spoiled food. The decision comes down to how long you are away, whether the appliance can be emptied, and whether anyone can check on it.

Safety

Step by step

1. Decide by duration first.Up to two weeks, leave it on. Two to four weeks, it is marginal and the effort usually outweighs the saving. Over a month, switching off and emptying is worth doing properly.
2. Use holiday mode if the fridge has one.It holds the fridge compartment at around 12-15°C — cold enough to prevent mould and smell, warm enough to use much less energy — while keeping the freezer at -18°C. It only works with the fridge empty of perishables.
3. Empty the fridge of anything perishable before a trip of any length.Milk, meat, fish, opened jars, salad, leftovers. Even with the appliance running, two weeks is longer than most of it keeps, and you will come home to a smell rather than a meal.
4. Never switch off a freezer with food in it.It is not a saving, it is a write-off. A full freezer holds safe temperatures for roughly 24 hours unopened and a half-full one about 12; after that everything in it must be dealt with, and most of it must be thrown away.
5. If you are switching off, empty it completely and clean it.Every shelf and drawer out and washed, the interior wiped with a bicarbonate solution and dried, the drain hole cleared and the door seal cleaned and dried. Anything left inside a warm, closed cabinet for a month will not be pleasant.
6. Prop the door open.This is the step that matters. A rolled towel, a wedge, or the door's own holiday catch if it has one. A sealed, switched-off cabinet grows mould in the seal channel and the smell soaks into the plastic liner permanently.
7. Leave the appliance switched off at the socket rather than just on its dial.And leave a note on the door or the consumer unit so nobody switches it back on to an open door and a warm cabinet.
8. If you leave the freezer running, protect it against a power cut.Fill empty space with bottles of water to add thermal mass. Put a plastic tub with a frozen cup of water and a coin resting on the surface of the ice inside — if you come home to the coin at the bottom of the cup, the contents thawed while you were away and refroze, and everything must be treated as unsafe.
9. Restart it properly on your return.Wipe it out, close the door, switch on and give it two to four hours to reach temperature before loading it, checked with a thermometer rather than by feel.

Tips

• A fridge freezer on holiday mode still keeps the freezer at -18°C, so it does not solve the power-cut question — it just stops you wasting energy chilling an empty fridge.
• Ask a neighbour to check the appliance rather than to check the house. Someone who opens the door once a week will notice a failure while it is still fixable.
• The coin-on-ice trick is the single most useful thing you can leave in a freezer you are going away from. It costs nothing and answers a question you otherwise cannot answer.

Common mistakes

• Switching a fridge off and closing the door — A warm, sealed, slightly damp cabinet is an ideal mould incubator. Within a month it grows through the seal channel and into the plastic, and the smell frequently outlasts every attempt to clean it.
• Switching off a freezer to save money over a two-week holiday — The saving is a couple of pounds. The cost is everything in the freezer, and refilling a freezer costs far more than running it does.

Questions people ask