This post overlaps with a fuller one: Furnace Replacement Cost: Why Two Quotes Differ by Half.
A furnace replacement price is set by the job, not the box. Two homes in Pasadena, CA can get quotes that differ by half and both be correct. Here are the things that move the number, in the order they usually matter.
What moves the price
- Fuel and system type. A gas-for-gas swap is the simplest job. Electric furnaces cost less as equipment but more to run here. A heat pump replaces furnace and AC together and is a different, larger job.
- Size. Chosen by a load calculation on the house, not square footage. Oversized furnaces short-cycle and wear out early.
- Efficiency (AFUE). Standard furnaces sit roughly in the low 80s, condensing furnaces in the 90s. Higher costs more up front, and with our short heating season the payback is slower than in a cold climate.
- Venting. Condensing furnaces vent through PVC and need a condensate drain. In a closet furnace with no path to an outside wall, that pipe run is a real share of the quote. This is the biggest reason two quotes for the same efficiency differ.
- Ductwork. When the air handler is replaced, California's Title 24 requires third-party duct leakage testing (HERS, now ECC), and failing ducts get sealed. New attic ducts go in at R-8. A quote that skips this is leaving something out.
- Permit and inspection. Required for a change-out in every city we work in. Ask whether the quote includes it.
- The extras. Thermostat, gas line modification, haul-away, and warranty terms. Anything at the electrical panel is a separate licensed trade.
How to compare quotes
Get them itemized: model number, AFUE, how the size was chosen, venting and duct scope, permit, disposal, and the parts and labor warranty. Then compare like with like.
The full guide: Furnace Replacement Cost: Why Two Quotes Differ by Half.
For a written quote, or a $69 diagnostic on the furnace you have, call the Boost Services team at 818-277-5056 or send us a message.
Written with AI assistance by Boost Services, Heating and Cooling team, and reviewed by our licensed technicians before publishing. Boost Services Heating and Cooling, C-20 #1119892.