Furnace Installation & Replacement in Milpitas, CA

When should I replace my furnace?

Replace it when keeping it running costs more than it gives back. Many furnaces last 15 years or more, so age alone is not a reason. These signs point toward replacement:

• The furnace is about 15 years or older and needs a major part, like a heat exchanger or blower motor.
• Repairs are getting more frequent, or gas bills keep climbing.
• Some rooms stay cold, even when the furnace runs for a long time.
• A technician has found a cracked heat exchanger (the part that heats the air).

If the problem is a single worn part on a furnace that is otherwise sound, a heating repair is usually the better value. We will tell you honestly which way makes sense.

Should I choose an 80% or a 95% furnace?

Choose an 80% furnace for a simple swap in the same spot, and a 95% condensing furnace if you want to burn less gas and the furnace can be vented through a wall or roof. The number is the furnace’s AFUE: the share of the gas it burns that becomes heat in your home.

A 95% furnace sends cool exhaust out through PVC plastic pipes and needs a condensate drain for the water it makes. An 80% furnace uses a metal flue. In our mild climate, a furnace runs fewer hours than in colder places, so the savings from a 95% furnace are real but smaller. We install both. Our heating page has a full side-by-side comparison.

What size furnace does my home need?

Your home needs a furnace sized to how much heat it loses, not just one that matches the old unit’s label. The old furnace may have been oversized from the start, or your home may have changed since, with new windows, insulation or an added room.

A furnace that is too big turns on and off often, which wears it out and leaves hot and cold spots. One that is too small runs and runs on cold nights. We look at your home’s size, insulation, windows and ducts, and size the new furnace to fit.

What happens during a furnace installation?

1. Free estimate. We visit, check your furnace, venting, ducts, gas line and electrical, and give you a clear written quote.
2. Permit. We pull the city permit for you.
3. Removal. We disconnect the old furnace and haul it away.
4. Venting and drain. We install the right venting for the new furnace: a metal flue for an 80% furnace, or PVC pipes and a condensate drain for a 95% furnace.
5. Gas and electrical. We connect the gas line and the electrical, and check for gas leaks.
6. HERS testing where required. When the job calls for it, a HERS rater (an independent energy tester) checks the system for the permit. We schedule it for you.
7. Test and walkthrough. We run the furnace, check that it heats properly and safely, and show you how it and the thermostat work.

Should I get a heat pump instead of a furnace?

A heat pump is worth a look if your air conditioner is also getting old. A heat pump heats your home in winter and cools it in summer, using electricity instead of gas, and it usually connects to your existing ducts.

Some local utilities and programs offer heat pump rebates. You may qualify; call us and we’ll check what applies to your home. Our rebates page lists programs by city.

Do the new Bay Area rules mean I have to replace my furnace?

No. As of November 2026, the Air District’s zero-NOx rules apply to new gas furnaces made from January 1, 2029, and only when a furnace is replaced. A working furnace does not have to be replaced.

They were honest, very pleasant to work with and they did not try to upsell us anything we don’t actually need.

Ellen I., Yelp review

Which furnace brands do you install?

We install any brand you want, including Amana, Carrier, Payne, Goodman and Daikin. You can see recent work in our furnace replacement in Fremont and our furnace replacement and Carrier heat pump installation in Hayward. Upgrade Home Services is a family-owned company based at 743 Ames Ave in Milpitas, licensed by the California Contractors State License Board (CSLB #1066776) and serving homeowners since 2002. We work across 22 cities in Santa Clara, San Mateo and southern Alameda counties, including Milpitas, San Jose, Fremont, Sunnyvale and Cupertino.