The worst result of problems with a power supply is normally an hour in the dark and a frantic search for a long unused candle. But when we had a power surge recently, we were without power for 19 hours and my children ended up bathing in a paddling pool.

A fault in an electricity substation that supplied our home resulted in a huge surge in voltage pulsing through our area in north London, affecting more than 300 properties and causing a frightening aftermath. Appliances were unusable, our kitchen sockets didn’t work, the electric shower was broken and our internet was down.

The timing could not have been worse – my brother was getting married and my mother was coming to stay amid the black sooty marks left on the walls where the plugs are.

Problems such as this are unusual, but not unheard of. Manchester Airport was hit by one last month. Here is what to do if one happens to you.

Why do they happen?

They are often the result of severe weather events, equipment failures or cyber-attacks. The one that affected us was due to a fault on a cable at the substation which caused changes in the voltage, according to UK Power Networks, the distribution network operator (DNO) that serves London, the south-east and east of England.

If you have a power cut – they typically last for less than 50 minutes – check your network operator’s website for updates. You might be able to sign up for text message alerts, too. Find your operator on the Energy Networks Association website.

You can also call your network operator free on 105 for advice. Keep a torch handy in case you are without power during the night. And avoid opening the freezer – food can last between 24 and 48 hours if there’s no power and you keep the door closed.

Can you get compensation?

This depends on the length of the cut, and the cause. In normal weather, if you are without power for 12 hours or more, you can claim £95 from your DNO as a residential customer. Businesses can claim £180. You can get a further £40 for each additional 12 hours.

If the cause is severe weather, you can get £85 if you’ve been cut off for 24 hours, with an extra £40 for every six hours afterwards. This is a “storm category one”.

For more severe storms, there is “storm category two”, where households must endure 48 hours before receiving £85 compensation. They get another £40 for every six hours afterwards. The maximum you can claim for either category is £2,000.

Customers on the priority services register, a free register for vulnerable people and households with children under five, are compensated automatically. If you don’t hear from your DNO, claim on its website.

What about a power surge?

There are no separate rules. Instead, it is a similar situation to a power cut. Network operators are not liable, but often do help to fix things. For example, we received £300 from UK Power Networks for our ordeal and an additional £50 for a paddling pool to keep the kids clean in the absence of a shower, as well as two nights in a Premier Inn.

Under the rules, we would have received £95 as it was normal weather, and the power cut was for more than 12 hours, but less than 24. UK Power Networks offered us more as a goodwill gesture. It also arranged for a contractor to repair or replace broken appliances in people’s homes for free. Somehow our ancient boiler survived, but many of our neighbours were not so lucky. Others had broken freezers, washing machines and TVs. Most were fixed or replaced.

Network operators have a customer care team to assist with major incidents, so see what extra help is on offer.

Can you claim on insurance?

If anything is damaged, you may be able to claim on your home contents insurance. The one thing that UK Power Networks would not cover us for was food ruined in the freezer.

According to financial analysts Defaqto, 95% of home insurance policies do cover frozen food, paying out up to £500 or £1,000. Angela Pilley, a home insurance expert at Defaqto, says claims depend on the damage, and the ability to prove what the cause was. “For example, it may be covered under accidental damage, as the damage would be caused suddenly, by external means, and is not expected or deliberate,” she says. “If it is more extensive, such as the surge caused a fire, then fire damage is typically standard.”

How common are power cuts?

The most recent Ofgem data says that between 25% and 50% of households suffered a power cut – or “customer interruption” – of more than three minutes in 2021-22. Depending on where you live, some DNOs seem to perform better than others. Northern Powergrid, covering the north-east, Yorkshire and northern Lincolnshire, had the most, at 50 incidents for every 100 customers, while Electricity North West had 26.

UK Power Networks has seen an increase. In 2022-23, there were 37.2, a 16% rise on the previous year. It says households in its area experience one, on average, every 32 months.

What about the future?

James Holton, energy expert and founder of Business Solar UK, thinks power surges are becoming more common, although there is little by way of official figures.

Steven Hardman, chief executive of Conrad Energy, a power producer, agrees, saying: “They are often caused by lightning strikes, sudden changes in electricity usage or faults in the grid. The increasing frequency of extreme weather events, driven by climate change, is a significant contributor.”