When the Ridge Finds the Weak Part
A house on the top road loses heat faster than one tucked lower down, so its boiler spends more of the winter running and more of that time near full output. That extra work rarely causes a fault on its own. What it does is find the component that was already on its way out — a pump with a tired bearing, a fan starting to labour, an expansion vessel that has slowly lost its charge — and push it over the edge on the coldest morning of the year.
The useful thing about being in the village is that an early symptom can be looked at before it becomes a cold house. A boiler that has started to rumble, takes several attempts to fire, or loses a little pressure each week is telling you something. We would rather see it then, while it is a planned repair, than in January when it has stopped altogether.
Sludge plays a part here too. West Yorkshire's soft water causes corrosion rather than limescale, and the magnetite it leaves behind restricts flow through the heat exchanger. On a hard-working ridge-top system that shows up as kettling and overheating lockouts, so it is checked for before any boiler part takes the blame.