Repair vs Replace, and Furnace+AC vs Heat Pump

The rough rule: if the repair costs more than a third of a new system and the unit is past 12–15 years, replacement usually wins. A young furnace with a failed igniter is worth fixing; an old one with a cracked heat exchanger is a safety reason to replace now. Factor in efficiency too — an old 80% furnace replaced by a high-efficiency unit pays back part of its cost in lower gas bills. Repeated repairs on an old system are money thrown at a problem that is only getting worse.

A gas furnace with central AC is the proven Michigan setup: cheap, powerful heat in deep cold and reliable cooling in summer. A cold-climate heat pump does both jobs efficiently on electricity and qualifies for strong incentives, but very cold nights can strain it — which is why many homeowners run a heat pump paired with a gas furnace for backup, getting efficiency most of the year and brute-force heat when it plunges. Your insulation, ductwork, and energy prices tip the balance.

There is no universal answer — the right call depends on your equipment’s age and condition, your home’s envelope, and current rebates. A licensed HVAC pro who runs a load calculation and looks at your actual ducts and gas line can tell you whether a repair buys you enough time, and which replacement path fits your house and budget. The pros in our network give you that straight assessment instead of defaulting to whatever they would rather sell.