How To Reset Your Boiler After A Power Cut

If your home’s lights have gone off, and you’re using your cellphone’s data to search why your boiler’s screen is blank, you’re in the middle of a power cut.

There’s no getting around it: power cuts are incredibly frustrating.

But if your heating and hot water don’t come back on, it can feel like the universe is playing a cruel joke on you.

Firstly, don’t panic. Resetting your boiler after a power cut is usually a straightforward task.

There are a few steps to follow to ensure you reset your boiler properly after a power cut, which include the following:

Step 1: Make Sure The Power Is Back On

It’s obvious when reading on your screen, but before you do anything, make sure that the electricity has actually come back on.

There are several signs that the power has returned, such as lights flickering to life or your internet connection reestablishing with your phone.

Once you’re sure the power is back, but the boiler has no power after the power cut, look for your boiler’s little white switch (the fused spur) or plug socket nearby.

Check to see if the switch is on.

If it’s already on, flick it off and on again to refresh the supply.

However, if there’s still no lights on the display, take a peek at your fuse box.

A tripped breaker might be the culprit.

Step 2: It’s On, But Nothing Is Working?

If you have no hot water and your boiler is on, remember that most boilers run a short self-check.

If the screen is still blank, don’t stress; it just means your boiler needs a reset.

Be aware that reset processes can vary widely depending on the boiler’s brand, model, and age.

Additionally, numerous resources are available online to guide you through resetting your specific boiler.

Step 3: Hit The Reset Button

Every boiler has a slightly different method for resetting it.

Many boilers have a dedicated reset button that must be held down for a set period, typically between three and ten seconds.

The amount of time will usually be in the manual.

If your boiler has a dial interface, you will usually need to set it to reset mode and then push in the knob.

Some modern models may require activating the reset function via the digital display.

Again, make sure to refer to the manual for the steps involved.

If everything has gone correctly, the boiler should whirr, click, and attempt to restart.

Step 4: Check Boiler Pressure

Power cuts can sometimes nudge the pressure out of range.

Boilers like to sit at 1.0–1.5 bar when cold.

If the water pressure is too low, you will need to top it up using the filling loop (usually a small silver hose with taps).

Depending on your boiler’s brand, model, and age, these repressurisation steps will vary widely.

If your pressure gauge is creeping into the red, grab a radiator key and bleed a radiator to bring it back down.

However, if everything is working correctly, it’s time to test your heating and hot water.

Step 5: Test Your Heating And Hot Water

To test if your home’s boiler is working, turn on a hot tap, and then turn on your heating.

If both fire up, you’re back in business!

However, if you’re still having issues, it’s time to do some troubleshooting.

Step 6: If It Still Won’t Reset, Time To Troubleshoot

So, you’ve pressed the reset button, checked the pressure, and your boiler is still sulking?

Don’t worry, here are a few more things you can try before reaching for the phone to call in a professional.

Check Your Gas Supply

Sounds obvious, but sometimes the issue isn’t the boiler at all.

The quickest way to check is to light your hob or gas stove.

If the flame flickers to life, your gas is fine.

If not, the supply might be off or interrupted, and you’ll need to contact your provider.

Reset Your Thermostat And Timer

Power cuts often mess with settings. Your thermostat might have reverted to factory mode or your timer could be flashing at random.

Double-check both and reprogram them if needed. It’s amazing how often this simple fix gets the heating back on.

Look For An Error Code

Modern boilers like to leave clues.

If your display is showing a flashing number or letter, that’s the boiler’s way of telling you what’s wrong.

Grab your manual (or Google the model number + error code) to see what it means.

However, if you’ve gone through this quick self-check list, it’s time to call in the professional.

Time To Call In A Professional

If you’ve tried all of the above and your boiler is still giving you the cold shoulder, it’s time to hand it over to the experts.

Luckily, WarmZilla has an extensive network of Gas Safe registered engineers across the UK who can be at your property within 48 hours.

Often these professionals can quickly diagnose and fix the issue, which will save you the stress of trial and error.

If you are looking for verbal assistance over a phone, feel free to contact our call centre to chat to one of our many professionals standing by to take your calls.