Boiler Reset Button: When to Press It (and When Not To)

If your boiler suddenly stops and a reset light appears, it can be tempting to press the reset button straight away. Used correctly, it can get your heating back on, but used at the wrong time it can hide serious faults and put your system at risk.

What the boiler reset button actually does

Modern boilers have built-in safety controls that shut the boiler down if something is not right. This is known as a lockout and it is designed to protect you and the boiler from damage.

The reset button clears the lockout and tells the boiler to try again. If the issue was only temporary, your boiler may run normally after a single reset. If the fault is still there, the boiler will usually lock out again and may show an error code or flashing light.

Checks to make before you press reset

Before touching the reset button, spend a couple of minutes checking a few basics. These simple checks can avoid repeated lockouts and help you spot problems early.

• System pressure: Look at the pressure gauge on the front of the boiler or nearby pipework. When the system is cold, most boilers should sit around 1.0 to 1.5 bar. If it is below 1 bar, your boiler may lock out. If you know how to safely top up using the filling loop, do that first. If not, call an engineer.

• Gas supply: Make sure the gas isolation valve near the boiler is in the open position and check other gas appliances, such as a hob, are working. If they are not, contact your gas supplier and do not keep resetting the boiler.

• Controls calling for heat: Check that the programmer or timer is set to “on”, the room thermostat is turned up, and any individual radiator controls are open. A reset will not fix incorrect settings.

Once these simple points are confirmed, you can decide if a one-off reset is reasonable or if you should call a professional straight away.

Safe situations for a one-off boiler reset

There are a few common, low-risk scenarios where a single reset is usually fine, as long as you have done the basic checks.

Temporary ignition or flame fault

Sometimes the boiler may fail to light properly due to a brief disruption to the gas supply or a gust of wind affecting the flue. The boiler locks out to be safe and asks to be reset.

If this happens once, and everything else seems normal, a single reset often clears the issue. If it becomes a pattern or you see the same error code repeatedly, you need an engineer.

Minor pressure dip after bleeding radiators

Bleeding radiators releases trapped air but can also lower the water pressure in the system. If the pressure drops too low, the boiler will shut down.

If you have recently bled radiators and now see low pressure, carefully re-pressurise the system to the recommended cold range, then try one reset. If the pressure keeps falling, stop and arrange a call-out.

Short power interruption

A brief power cut or tripped fuse can confuse the boiler’s electronics and lead to a lockout. Once the power is stable again, a single reset is usually all that is needed.

If you regularly lose power, consider having an electrician check the supply rather than constantly resetting the boiler.

How to reset your boiler safely

Each model is slightly different, so always check your user manual for exact instructions. However, most modern boilers follow a similar pattern.

First, locate the reset control. It may be a dedicated “reset” button, a dial position marked with a symbol (often a circular arrow), or a soft-touch control on a digital panel.

On many boilers you will need to press and hold the reset button for a few seconds rather than just tapping it. Check the manual for how long to hold, as some need 2 to 5 seconds, while others need a simple press.

After pressing reset, wait and listen. The boiler should go through a start-up sequence: fans running, clicking of ignition, then the sound of the burner lighting. This can take a minute or two. If it fails to ignite and locks out again, stop resetting and call an engineer.

Red flags: when not to press reset

There are clear situations where pressing the reset button is not safe and you should contact a Gas Safe registered engineer promptly.

Gas smells or signs of combustion issues

If you can smell gas in your home, do not reset the boiler. Turn off the gas at the meter if safe to do so, open windows, avoid switches and flames, and call the National Gas Emergency number immediately.

Similarly, if you see sooting around the boiler, yellow or unstable flames (where visible), or feel unwell with headaches or nausea near the boiler, turn it off and seek urgent professional help.

Visible leaks, drips or corrosion

Water leaking from the boiler or pipework, or signs of rust and staining, mean something more serious is happening. Resetting will not fix leaks and can make problems worse.

Turn the boiler off at the controls and the main power switch, place a container or towel under any drips, and contact an engineer.

Repeated lockouts or returning error codes

Using the reset button more than occasionally is a warning sign. If the boiler keeps locking out, or the same error code appears after every reset, something inside the boiler needs attention.

Do not keep pressing reset day after day. This can stress parts, hide faults, and in some cases lead to more expensive repairs later on.

Flue and condensate issues

If the flue outside looks loose, damaged, blocked by debris, or has been affected by strong winds, do not restart the boiler until it has been checked. A blocked flue can affect combustion and safety.

In winter, the plastic condensate pipe that runs outside can freeze. This often causes a lockout with a specific error code and gurgling noises. You can sometimes safely thaw it with warm (not boiling) water, but if the problem repeats, ask an engineer to look at the pipework.

FAQ on boiler reset buttons

How many times can I reset my boiler?

As a general rule, one reset after you have checked pressure, controls and gas supply is reasonable. If the boiler locks out again, do not keep trying. Most manufacturers expect you to stop after one or two failed resets and call an engineer.

Will resetting clear a fault permanently?

Resetting only clears the lockout message and lets the boiler try again. If the fault was a one-off glitch, it may not return. If there is an underlying issue, it will usually come back.

Think of reset as restarting a computer. It is useful, but it does not repair broken components or fix persistent problems.

Can resetting damage a boiler?

Using the reset button as intended, very occasionally, is perfectly safe. Constantly resetting a boiler that is trying to protect itself is not.

Repeated lockouts and resets can put strain on ignition parts and pumps and might allow a minor issue to grow into a major failure. If in doubt, stop resetting and get professional advice.

When to call Westhill Boiler Services

If your boiler needs resetting more than once in a while, or the same fault keeps coming back, it is time for expert help. Book a boiler repair visit with Westhill Boiler Services and an engineer can find and fix the root cause instead of just clearing the symptoms.

Regular maintenance also reduces the chances of lockouts in the first place. If your boiler service is overdue, arrange an annual service with Westhill Boiler Services to keep your heating running safely and efficiently. To book an appointment or ask for advice, call 01224548803.