HVAC Replacement Cost in San Mateo, CA (2026)
Updated October 2026 · San Mateo, CA · index 1.23
How much does a new HVAC system cost in San Mateo? For a 3-ton system with central AC + gas furnace, homeowners in San Mateo, CA pay about $12,900 on average, and most quotes land between $8,800 and $16,900 — $2,926 to $5,641 per ton. The price covers removing the old system, the new outdoor and indoor equipment, a new line set, electrical and condensate connections, the thermostat, the permit, start-up and commissioning.
The HVAC replacement price in San Mateo runs 23% above the U.S. average: construction labor in the San Mateo area runs 36% above the national mean, materials 4% above. The same job averages $10,500 nationally and about $11,800 at the California statewide index.
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HVAC replacement price in San Mateo by system type
What a 3-ton system costs in San Mateo with each system type, installed:
| Option | Average · range |
|---|---|
| Central AC + gas furnacesplit AC, matched coil and an 80,000 BTU furnace$4,284 per ton | $12,900$8,800 – $16,900 |
| Heat pump + air handlerall-electric split heat pump, no furnace$3,972 per ton | $11,900$8,000 – $15,800 |
| Cold-climate heat pump + air handlervariable-speed heat pump rated for deep winter$4,541 per ton | $13,600$9,200 – $18,000 |
The least expensive option in San Mateo is heat pump + air handler, at about $11,900; cold-climate heat pump + air handler averages $13,600, 1.1 times as much.
Cost to replace an HVAC system in San Mateo by size
With central AC + gas furnace, priced for San Mateo, CA:
| Size | Average · range |
|---|---|
| A 2-ton system$5,572 per ton | $11,100$7,600 – $14,700 |
| A 3-ton system$4,284 per ton | $12,900$8,800 – $16,900 |
| A 4-ton system$3,640 per ton | $14,600$9,950 – $19,200 |
Some costs stay the same whatever the size — load calculation and equipment sizing, mechanical permit and inspection, old system removed, refrigerant recovered — so a bigger job costs less per unit: $3,640 per ton for a 4-ton system against $5,572 for a 2-ton system.
What an HVAC replacement in San Mateo includes
Line by line, the $12,900 average for a 3-ton system breaks down like this: 32% labor, 65% materials and equipment, and $280 in permit fees passed through at cost.
| Line | Low – high |
|---|---|
| Load calculation and equipment sizing | $90 – $280 |
| Mechanical permit and inspection | $150 – $400 |
| Old system removed, refrigerant recovered | $420 – $750 |
| Gas furnace (about 80,000 BTU) | $1,850 – $3,350 |
| Outdoor unit, set on a new pad | $2,800 – $5,250 |
| Matched indoor coil | $1,200 – $2,600 |
| New refrigerant line set (25 ft) | $470 – $750 |
| Disconnect, whip and thermostat wire | $260 – $420 |
| Condensate drain and safety switch | $140 – $330 |
| Gas connection and furnace venting | $390 – $730 |
| Plenums and transitions to the ducts | $330 – $750 |
| Programmable or smart thermostat | $280 – $510 |
| Evacuation and refrigerant charge | $140 – $280 |
| Start-up and commissioning | $140 – $330 |
| Warranty registration and walk-through | $70 – $160 |
Each line is the price book's U.S. rate for that step, scaled by 0.76 to the installed price published sources give for the whole job (see how these prices are built), times San Mateo's index of 1.23; permit fees are not scaled.
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What affects HVAC replacement prices in San Mateo
Labor and materials in San Mateo
Construction wages in the San Mateo metro run 39% above the U.S. mean (BLS, May 2025), and specialty-contractor pay in the city's county moves that down by 2%, to 36% above the national mean. Materials in the area's ZIP codes price 4% above the national average. Together they give San Mateo a construction cost index of 1.23.
Where San Mateo sits in California
San Mateo is the 5th most expensive of the 22 California cities in our index, against a statewide index of 1.13. San Francisco is the dearest at 1.30; Riverside is the least expensive at 1.05.
Against the rest of the country
Of the 306 U.S. cities in JobFlex's index, San Mateo ranks 24th from the most expensive. The job that averages $12,900 here averages $10,500 at the national rate.
Climate a system is sized for in California
Contractors size equipment for the local design temperatures. Across California's counties the median is about 100°F on a hot summer day and 24°F on a cold winter night (ENERGY STAR county table), and your county can differ. A standard heat pump handles most winters here; a furnace or a cold-climate model covers the coldest nights.
Sales tax in California
California's base state sales tax is 7.25%, and cities and counties can add their own. How it applies to a home-improvement contract varies, so ask whether a quote includes it. Prices on this page are before tax.
What a San Mateo contractor will ask before quoting
- Job type — new construction, replacement or upgrade — and the evidence for it
- Heating and cooling load for this house (not the old nameplate), tonnage, fuel and refrigerant
- Ducts, line set, circuit, gas line and flue: keep, fix or replace, each with its reason
- Water heater in scope, and whether it shared the old flue
- Panel main amps, free slots and the new equipment's MCA
- Permits, tests and incentives that apply in this state
HVAC replacement cost in other California cities
A 3-ton system with central AC + gas furnace averages $12,900 in San Mateo; $12,500 in Walnut Creek, $13,500 in Palo Alto, $13,200 in Oakland.
| City | Average · range |
|---|---|
| Walnut Creek, CA2% less | $12,500$8,550 – $16,500 |
| Palo Alto, CA5% more | $13,500$9,200 – $17,700 |
| Oakland, CA2% more | $13,200$9,000 – $17,300 |
| San Jose, CA4% more | $13,400$9,150 – $17,600 |
| San Francisco, CA6% more | $13,600$9,250 – $17,900 |
| Santa Rosa, CA6% less | $12,100$8,300 – $16,000 |
| San Diego, CA10% less | $11,600$7,950 – $15,300 |
| Sacramento, CA10% less | $11,600$7,950 – $15,300 |
HVAC replacement price in San Mateo: questions
How much does a new HVAC system cost in San Mateo, CA?
About $12,900 for a 3-ton system with central AC + gas furnace, and most San Mateo quotes fall between $8,800 and $16,900. That is 23% above the U.S. average, where the same job averages $10,500.
What is the HVAC price per ton in San Mateo?
$2,926 to $5,641 per ton, about $4,284 on average with central AC + gas furnace. Smaller jobs cost more per unit, because the fixed costs are spread over less.
How much is a 4-ton system in San Mateo?
$9,950 to $19,200, about $14,600 on average, with central AC + gas furnace — $3,640 per ton.
Do you need a permit for HVAC replacement in San Mateo?
Yes — installing HVAC or fuel-burning equipment needs a permit nearly everywhere, San Mateo included. The prices on this page carry $150–$400 for the permit and inspection.
Does the price include sales tax in California?
No. The prices here are before tax; California's base state rate is 7.25%, plus any local rate.
What size HVAC system does a house in San Mateo need?
It is worked out with a Manual J load calculation for the house — included in the prices above — not from square footage alone. Here it is run against design temperatures of about 100°F in summer and 24°F in winter (the California median).
Other home projects in San Mateo
HVAC replacement cost in California
- HVAC replacement cost in Walnut Creek, CA
- HVAC replacement cost in Palo Alto, CA
- HVAC replacement cost in Oakland, CA
- HVAC replacement cost in San Jose, CA
- HVAC replacement cost in San Francisco, CA
- HVAC replacement cost in Santa Rosa, CA
- HVAC replacement cost in San Diego, CA
- HVAC replacement cost in Sacramento, CA
How these prices are built
Every price on this page comes from JobFlex's contractor price book: what a homeowner pays a licensed contractor for each step of the job, as a U.S. national average per unit, with the contractor's overhead and profit included and sales tax left out. The HVAC replacement is priced step by step, then multiplied by San Mateo's construction cost index of 1.23.
Where the price book's steps for an option add up to more than 20% over the installed price a published source gives for the whole job, every step but a permit fee is scaled down to the middle of that range: central AC + gas furnace × 0.76 (HomeCostCalcs 2026: $7,000–$14,000); heat pump + air handler × 0.76, following central AC + gas furnace; cold-climate heat pump + air handler × 0.76, following central AC + gas furnace.
The index weighs local construction wages (BLS Occupational Employment and Wage Statistics, May 2025) at 60% and the area's material prices (Craftsman ZIP-area factors) at 40%. Published indices for San Mateo, each on its own base: HUD 1.28, Craftsman 1.19. Treat any city figure as about ±5%; a contractor's quote for your house is the number to plan with.
Contractors in San Mateo build quotes like these with JobFlex's HVAC estimator.
- HomeCostCalcs 2026: furnace + AC replacement $7,000-$14,000 standard, $10,000-$20,000 high efficiency
- Today's Homeowner 2025: complete HVAC system install $5,000-$12,500