Tankless water heaters in Triangle.

Three in four Triangle owner homes heat with gas, which makes tankless possible for most. The houses split in two. About one in six predates 1960, in plats like Carborough Heights, Mockingbird Heights and Amidon. A big share of the rest went up in the 2000s, in Kerill Woods, Cramers Ridge, Lionsfield Valley and Garrison Woods. They need very different things.

In the 1950s ranches and cape cods, the gas line was run for a small furnace and a small tank. Going tankless there usually means a larger line from the meter, and the old masonry chimney cannot be used for a condensing unit. The venting leaves through PVC in a side wall instead, and the basement or utility room often has an outside wall for it.

The 2000s subdivisions are the other end. A gas line from that era more often has room, so the work shrinks to the exhaust pipe, the intake and a place for condensate to drain. Garrison Woods and Lionsfield Valley were both recorded in 2004, so their original tanks are now about twenty years old.

Port O’Dumfries is the odd one: townhouses on Masthead Trail and Tavern Way with Triangle mail, but inside the Town of Dumfries, built between 1972 and 1987. An end unit there has a side wall for the vent. A middle unit has very little outside wall, which can settle the question before the gas line does.