An older furnace, a new quote in your hand

The New York code points to a published sizing method, and NYSERDA adds that many existing furnaces were oversized themselves. An oversized furnace runs in short bursts all winter, tires its parts sooner and leaves rooms uneven. Ask each bidder for a load worksheet, and compare the quotes against that one sheet.

A real worksheet counts walls, windows, roof and floor and notes which way each faces. If a contractor cannot show one, ask how the size was chosen and who stands behind it.

Tell the contractor what has changed in the house. New windows, attic insulation, a finished basement or a closed-off room all change the heat the house loses, and the worksheet should reflect them. A figure that ignores those changes describes a house you no longer own.

A gas water heater that shared the old chimney loses its partner when a condensing furnace exhausts through the wall. Oak Ridge National Laboratory names the result an orphaned water heater and offers two fixes, a liner or a draft inducer, each at added cost.

Ask your contractor to price that line by name. If a bid is lower than the rest, ask whether it leaves the chimney alone.

Ask whether the contractor will inspect the chimney itself. A flue that has not been inspected in decades may need more than a liner, and you want that discovered before the work starts and not halfway through.

The Town of Manlius enforces the 2020 New York State Uniform Code and Energy Code, effective May 12, 2020, covering residential, fuel gas, mechanical and energy conservation work. No source here says whether the village runs an office of its own, so ask the village clerk which one covers your address.

After that, find out who files the paperwork and whether the fee is already in your price.

Keep a copy of the written scope and the model number. If a question comes up with whichever office handles your address, those two papers answer it.