Things stopped working after the power came back.

Unplug computers, televisions, and anything with a control board while the power is out, and leave them unplugged until the supply has been back and steady for a few minutes. The damage in an outage is often done at the moment power returns, not while it is off.

If something has already failed, write down what it was and when it stopped working, because the answer to who pays depends on establishing the cause.

What actually damages things

The restoration surge. When a utility re-energises a circuit, the inrush as every device on the street draws at once can produce a voltage spike. Modern switch mode power supplies handle a lot, and not everything.

Repeated cycling. Power flicking on and off several times, which happens while a fault is being located, is harder on motors and compressors than a single clean outage. A refrigerator or an air conditioner that restarts against pressure repeatedly can fail.

Brownouts. Voltage sagging rather than failing. Motors draw more current at low voltage and overheat, which is worse for a fridge or a furnace than a clean outage.

A lost neutral, which is a different and much more destructive problem, and which typically takes several devices at once. The signs of that, and why it is urgent.

Lightning, directly or nearby, which can enter through the supply, the antenna, or a network cable.

What tends to fail, and when

Immediately: power supplies, control boards, network equipment, LED drivers.

Days or weeks later: compressors in fridges and air conditioners, motors in furnaces and pumps, and anything where the damage was heat rather than a spike. That delay is why people fail to connect the failure to the outage, and why writing the date down matters.

What to do during an outage

• Unplug computers, televisions, audio equipment, games consoles, network gear, and anything with a screen or a control board.
• Switch off the air conditioner and the heat pump at the thermostat, so they do not restart into a brownout.
• Leave one lamp on so you know when it returns.
• Wait a few minutes after it comes back before plugging things in, and bring them back one at a time.
• Do not switch everything back on at once, particularly motors.

Protecting against it properly

Point of use surge protectors are inexpensive and worth having on anything with a board. Note that a power strip is not necessarily a surge protector; look for a joule rating. They wear out absorbing surges, so replace them every few years and after any known event.

A whole house surge protector, installed at the panel by an electrician, is the better answer and is not expensive relative to what it protects. It handles what comes in on the supply; point of use devices still matter for what happens inside the house.

An uninterruptible power supply for a computer or a home office, which also rides out the flicker that causes most data loss.

Neither protects against a direct lightning strike. Nothing at this price does.

If something has failed

1. Write down what, and when. Model and serial numbers, the date it stopped, and the date and time of the outage.
2. Do not throw it out. Nobody pays for something they cannot inspect.
3. Photograph it, including any scorch mark or smell.
4. Get a repair report, if it is worth repairing. A technician’s written statement that the failure was a voltage event is what turns an assertion into evidence.
5. Check for a pattern. Several devices failing at once points at the supply rather than at coincidence, and that is a much stronger claim.

Who might pay

Your insurer. Many policies cover sudden and accidental damage from artificially generated electrical current, sometimes as an add on, and often excluding tubes and some components. Sub-limits are common. What a policy does with electrical damage.

The utility. Usually only where they were negligent, and most tariffs limit their liability for voltage variation. It is still worth filing, particularly after a lost neutral or a documented fault on their equipment, and they have their own deadline.

The manufacturer, if the device was under warranty, although surge damage is commonly excluded.

Run these in parallel rather than one after another, because each has its own clock.

The short version

Unplug the sensitive things while the power is out, and bring them back one at a time afterwards. Failures show up immediately or weeks later, so write down what died and when. Keep the dead item, get a written cause if you can, and file with both the insurer and the utility rather than choosing between them.