5 heatwave hacks that could put your home insurance at risk

As the nation continues to swelter, many people are trying every trick in the book to keep cool. But some heatwave hacks could put your home insurance at risk. 

Fans and opening windows, for example, may lower the temperature inside your home, but they could increase the chance of accidental damage or make your property more vulnerable to burglary. 

Here are five ways beating the heat could affect your buildings and contents cover.

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1. Installing air conditioning

Last month, the government’s climate advisers warned that British homes would need air conditioning to survive predicted levels of global heating. But they don't come cheap. Buying and installing units can set you back thousands of pounds. Even a simple portable unit costs a few hundred pounds, and running costs can also spiral.

If you're not put off by the price, the good news is that installing air conditioning shouldn't usually affect your home insurance.

Both Aviva and Admiral told Which? that you don't need to tell them if you install an air-conditioning unit, whether it's a portable model or a fixed system.  

However, there are a few caveats to watch out for. Tamzin Metcalfe, home insurance expert at Go.Compare, says it's sensible to speak to your insurer before carrying out work that involves structural changes, electrical alterations or could increase the rebuild value of your home.

That could include installing a fixed air conditioning system.

• Find out more: making a home insurance claim.

2. Putting water in front of fans

This is probably one of the most common and affordable steps you can take to keep your home cool. But when it's pushing 35°C outside, sometimes the breeze from a fan doesn't always cut it.

To help chill the air further, some people are placing a bowl of ice or cold water in front of the device. Or even putting a wet cloth over the fan. However, placing water close to electrical appliances or sockets could create a safety risk. 

If water damages an electrical appliance or contributes to a fire, your insurer may look at how the damage occurred when assessing a claim. 

Metcalfe says that insurers expect customers to take reasonable care of their home. If damage is caused by avoidable misuse or negligence, it could affect a claim. 

• Find out more: best and worst home insurance 2026.

3. Buying an unsafe appliance 

After several hot spells this summer, you may be tempted to buy the cheapest fan or portable air-conditioning unit you can find. 

However, it's worth being cautious when buying electrical appliances from unfamiliar online sellers. Products that don't meet UK safety standards, or are poorly made, could pose a fire risk.

If an electrical fault is linked to an unsafe appliance or misuse, your insurer may consider those circumstances when assessing a claim. Also, make sure any unit isn't left running unattended, especially overnight.

Ryan Sherdel, deputy head of household underwriting at Admiral, advises homeowners to take the following safety measures:

• Keep fans or air-con units clean. Dust and lint can build up around the motor, trapping heat and acting as fuel if a fault occurs.
• Check the cable and plug for damage. Plug it directly into a wall socket where possible. 
• Never use overloaded extension leads or sockets.
• Keep a clear space around the fan. Don’t use it close to combustible materials such as curtains, bedding or piles of clothing.
• Replace very old or damaged fans or fans that make unusual noises, emit a burning smell or become excessively hot. 
• Don’t use fans with worn motors or bearings, or frayed or damaged power cords.
• Turn it off when you are away from home for extended periods.
• If you can, use a timer only when you need cooling while falling asleep. 

4. Opening windows and doors

Leaving windows or doors open can improve airflow, but it may also increase the risk of burglary. If an intruder gains access through an open window or unlocked door, your insurer could decide that the property wasn’t properly secured and reject any theft claim. 

It goes without saying that if you're going out for the day or evening, make sure all windows and doors are closed. It's also worth checking that all locks are approved by your insurer. This will also help you to avoid any issues in case you need to make a claim. 

Aviva also warned homeowners to check the small print carefully. Some policies may not cover theft from the home, unless there's evidence of forcible and violent entry.

• Find out more: how to find cheap home insurance.

5. Covering windows with foil

One hack that has gained popularity on social media is covering windows with foil to block out the sun. While it may seem harmless, foil applied directly to windows can increase the risk of thermal stress in certain types of glazing, potentially causing the glass to crack. 

Metcalfe says this damage is often considered preventable, so your insurer may refuse to pay a claim. A safer approach is to keep curtains or blinds closed during the hottest part of the day. 

How to make a home insurance claim

If you need to make a claim following damage to your property, get in touch with your insurer as soon as possible. The time it takes for your insurer to process your claim can vary depending on the extent of the damage and the size of the affected area.

If you have to arrange emergency repairs yourself, tell your insurer and keep any receipts, as this will form part of your claim. Don’t throw away damaged items unless they pose a health risk, as they may be repairable or restorable. 

If you’re unhappy with how your insurer has handled a claim, your first step should be to raise an official complaint directly. If you still can’t resolve the issue or don’t feel you have been treated fairly, you should contact the Financial Ombudsman Service (FOS), which is free to use.

• Find out more: how to complain about your insurance company.