Pressure issues are one of the most common causes. As the system works harder, small losses become more noticeable. Repeated pressure drops can trigger safety shutdowns that require manual resets.
Restricted circulation also plays a role. Sludge, air pockets, or poorly balanced radiators can all cause uneven heating, forcing the boiler to shut down prematurely. If radiators also stop heating mid-cycle, that pattern is explained here: Radiators Stop Heating Mid-Cycle.
Cold weather can also affect external components like condensate pipes. Partial freezing may not cause a full lockout but can contribute to intermittent resets.
If resets are becoming routine, it’s usually a sign the underlying issue hasn’t been addressed. This broader explanation may help identify it: Why Your Boiler Keeps Needing Reset.
Understanding how boilers behave under load is part of managing heating costs and comfort, which is covered in the full guide here: How to Keep a UK Home Warm for Cheap.
For a structured way to narrow down the cause, use the diagnostic page here: House Cold Diagnostic Tool.