When I bought my current house it had a Potterton boiler, a vast heavy cast-iron thing housed in its own boiler shed against the real wall of the house. It must have been a couple of decades old then, but as it was always reliable I saw no point in changing it.
When I retired we decided to have the house completely renovated to provide more space as we were going to be there much more. We moved out while the work was done, so although knew it would involve new heating system, plumbing, wiring etc, didn’t think about specifying the make of boiler. That was a mistake. In the event we got a combi (because we had built into the loft space and had no water tanks any more) and a brand I had never heard of and since forgotten. It was nothing but trouble from the off and lasted about 10 years before replacement, but with lots of maintenance visits in between. “You did well out of this” was the judgement of our heating engineer. I suspect the old Potterton would still having been chugging along.
Current boiler is a Viessman with which we are very happy. Wasn’t so sure in its first winter as it is our first condensing boiler and the Beast from the East froze the outlet pipe. I have since heavily lagged that to hopefully prevent a recurrence. As it has a 10 year warranty I’m hoping it will fare slightly better than its processor, but nothing these days seems built to last.
PW