How to reset a Baxi boiler
Most Baxi boilers have a red reset button on the control box, usually located on the front or side of the unit. Press and hold it for about three seconds, then release. The boiler will attempt to restart and relight the pilot light. If the boiler fires up and the display shows normal operation, the reset worked. If it shuts down again within a few minutes, the reset button alone won't fix the underlying problem—you'll need to call a Gas Safe registered engineer.
The reset button exists because boilers shut themselves down as a safety measure when they detect a fault: a failed ignition, a flame loss, a pressure drop, or a sensor malfunction. Pressing reset tells the boiler to try the ignition sequence one more time. Sometimes a temporary glitch—a power dip, a stuck valve, condensation in the ignition system on a cold morning—causes a shutdown that a reset clears. Most of the time, if the boiler needed reset, it will need reset again soon, which means something is actually broken.
Key Takeaways
- The reset button is a red or black button on the boiler's control box; press it for three seconds and release to attempt a restart.
- A boiler that resets successfully but shuts down again within hours or days has an underlying fault that requires a Gas Safe engineer to diagnose.
- Never force the reset button or press it repeatedly in quick succession—one press every 15 minutes is the safe limit.
- If the boiler will not fire after a reset, or if you smell gas, do not attempt further resets; call your engineer or your gas supplier's emergency line.
- Baxi boilers display fault codes on their digital screen; write down the code before calling an engineer so they can prepare the right parts.
Where the reset button is located on Baxi models
The reset button location varies slightly between Baxi models, but it is almost always on the front-facing control box or PCB (printed circuit board). On condensing boilers like the Baxi 824, the button is typically a small red or black mushroom-shaped button near the bottom left of the front panel. On older fan-assisted models, it may be recessed slightly so you need to press firmly. Check your boiler's manual for the exact position—the manual should be in a pocket on the side of the boiler or available from Baxi's website if you search by your model number.
If you cannot find the button, do not poke around inside the boiler casing. Turn off the power at the wall switch, wait 30 seconds, and turn it back on. This soft reset sometimes works for electronic faults and is safer than hunting for a button you cannot see. If the boiler still will not start after a power cycle, call an engineer rather than opening the casing yourself.
What happens when you press the reset button
When you press the reset button, the boiler's control board clears any fault code stored in its memory and signals the ignition system to try lighting the pilot light again. You will usually hear a clicking sound as the ignition electrode sparks. If the pilot lights, the main burner should follow a few seconds later, and the boiler will resume heating. The display will show a normal operating screen—usually a temperature reading or a flame symbol—rather than a fault code.
The whole sequence takes about 10 to 15 seconds. If nothing happens after 30 seconds, the boiler has failed to ignite and will shut down again. Do not press the button again when ready; wait at least 15 minutes before trying a second reset. Repeated resets in quick succession can flood the combustion chamber with gas and create a safety hazard.
When a reset works and when it does not
A reset works when the shutdown was caused by a one-off event: a brief power cut, a temporary air lock in the gas line, or condensation that cleared as the boiler warmed up. After a successful reset, the boiler runs normally and does not shut down again. This is common in winter or after the boiler has been idle for a few days.
A reset does not work—or works only temporarily—when the fault is persistent: a faulty flame sensor, a blocked burner, a failing ignition electrode, low water pressure, or a broken pump. In these cases, the boiler may restart after a reset but will shut down again within minutes, hours, or a day or two. Each time it shuts down, it stores a new fault code. If you find yourself resetting the boiler more than once a week, or if it shuts down while running, the boiler needs professional diagnosis and repair.
Reading the fault code on your Baxi boiler
After a failed reset, your Baxi boiler will display a fault code on its digital screen. Common codes include E133 (flame loss), E119 (ignition failure), E181 (low water pressure), and E118 (sensor fault). Write down the exact code and any letters or numbers shown. This code tells an engineer what system failed without them having to run diagnostics first, which saves time and money.
Do not attempt to clear a fault code by unplugging the boiler or turning off the power for an extended period. The code is there for a reason, and clearing it without fixing the underlying problem just hides the fault until it happens again. If you see a code, take a photo of the display with your phone and send it to your engineer or your boiler's support line before booking a visit.
Safety checks before and after a reset
Before you press the reset button, check that the boiler's power switch is on and that the gas supply to the boiler is open. If the boiler has been without power or gas, turning these back on and waiting 30 seconds often restarts the boiler without needing the reset button at all. If you smell gas near the boiler, do not press reset; turn off the gas supply at the meter and call your gas supplier's emergency line when ready.
After a successful reset, listen for normal operation: the pump should hum quietly, the burner should roar gently, and the fan (if the boiler has one) should run. If you hear loud banging, whistling, or grinding, turn off the boiler and call an engineer. These sounds suggest a blockage, air in the system, or a failing pump—all things that need professional attention.
When to call a Gas Safe engineer instead of resetting
Call an engineer when ready if the boiler will not fire after a reset, if it shuts down repeatedly, if you smell gas, or if the display shows a fault code you cannot clear. You should also call an engineer if the boiler is under warranty and has just started shutting down—attempting resets yourself may void the warranty, and the engineer's visit is covered by the warranty anyway.
If the boiler is older than 15 years and resets are becoming frequent, it may be approaching the end of its life. An engineer can tell you whether repair is worth the cost or whether replacement is the better option. Baxi boilers typically last 10 to 15 years with regular servicing, so age combined with repeated faults is a sign that the boiler is wearing out.
Frequently Asked Questions
How many times can I safely press the reset button?
Press it once, wait 15 minutes, and try again if needed. Do not press it more than twice in an hour. Repeated resets in quick succession can flood the combustion chamber and create a safety hazard. If two resets do not work, stop and call an engineer.
Will resetting the boiler erase my heating schedule or settings?
No. A reset clears only the fault code and restarts the ignition sequence. Your programmed times, temperature settings, and any other stored preferences remain unchanged. The boiler will resume heating on its normal schedule once it restarts.
What if the reset button is stuck or will not press?
Do not force it. A stuck button usually means the control box has a fault or the button mechanism is broken. Turn off the boiler at the wall switch and call an engineer. Forcing the button can damage the control board further.
Can I reset the boiler by turning off the power at the wall?
Yes, this is a soft reset. Turn off the power switch for 30 seconds, then turn it back on. This clears the fault code and restarts the boiler without using the reset button. It works for some electronic faults but not for mechanical problems like a blocked burner.
Should I reset the boiler if it is making strange noises?
No. Strange noises—banging, whistling, or grinding—suggest a mechanical problem like air in the system, a blocked pipe, or a failing pump. Resetting will not fix these. Turn off the boiler and call an engineer to diagnose the noise.