Boiler repair and replacement in Dunn Loring.

ZIP 22027 holds 627 owner homes, more than nine in ten of them detached, and the typical one went up in 1991. About half were built between 1980 and 1999, mostly with furnaces and ducts, so a house here with radiators or baseboard is usually one of the older quarter, built before 1980.

Gas heats about two in three owner homes, so the boilers we meet in Dunn Loring are mostly gas-fired, with a few on propane. Almost none of the homes here are rented, so the person reading this is usually the one who decides whether to repair or replace. Electricity heats a little over a quarter of owner homes, mostly with heat pumps.

A cast iron boiler in one of those older houses vents up the chimney in metal pipe, and replacing it like for like keeps that path. A condensing boiler at $12,782 to $16,500 installed moves the vent to a plastic pipe through an outside wall and takes the chimney out of the job. In a mostly detached ZIP like this one, the boiler room is usually a basement corner with space to work, so a like-for-like cast iron swap is a straightforward job, and the written price says whether the chimney needs a liner once the boiler is no longer sharing it.

January 2016 buried the area under 23 to 31 inches of snow, the kind of week a tired boiler picks to quit. The fall tune-up, $69 a system, checks the pressure, the relief valve and the pump before a storm makes any of them urgent. Snow that deep also buries the plastic vent of a condensing boiler, so clear it after a storm or the boiler shuts itself off.