The problem: Replacing an existing gas furnace with a new, more efficient furnace. The apprentice: Allen Charles Edwards (ACE) — First-year mechanic. The technician: N. Arthur Thomas Egan (NATE) — ...

There's no problem with a one-pipe system, but the rules for venting are different. I've read dozens, maybe hundreds of high-efficiency furnace installation manuals. Every single one of them had ...

Skipping the manufacturer's instructions during installation may result in a furnace that fails within six months or less. For example, heat exchangers can crack from improper venting, and gas valves ...