AC installation and replacement in Stockton

What a new system costs

System	Published range, installed	Source
Central air conditioner	$5,800 to $14,400, $8,750 average	Fixr, August 2025
Heat pump	$5,000 to $15,000, $8,350 average	Fixr, January 2026
Ductless mini split	$4,577 to $8,328, $6,357 average	Fixr, January 2025

National published figures, not a Stockton quote. New ductwork, an electrical panel upgrade or a second system all add to the price.

Size it from the house, not the old unit

The Department of Energy's building science program says an oversized system cycles on and off too often, which wastes energy and leaves the house clammy, while an undersized one can't keep up. The fix is a load calculation (often called a Manual J) based on the house itself: square footage and insulation, plus the windows and which way it faces. In Stockton the west-facing rooms and second floors are where a bad sizing shows up first, on a 96.8 degree July afternoon.

A quote that just matches the tonnage of the old unit is a guess. Ask for the calculation.

The permit and the field test

California requires a permit when a central system is replaced, and an independent rater has to test the installed system. CHEERS, one of the state's registered providers for those raters, says the contractor pulls the permit, registers the job and schedules the test. The test checks things like duct leakage, which matters in older Stockton houses where the original ducts run through a hot attic. In the city of Stockton, permits go through the Permit Center at 501 W. Weber Ave, Building 2, First Floor. Other cities and the county have their own building departments. Permits and testing, step by step.

A company that offers a lower price for skipping the permit is offering to skip the test too. If you sell the house later, unpermitted work can come up.

Efficiency and refrigerant

• Split-system air conditioners under 45,000 Btu/h installed in California since 2023 must meet at least 14.3 SEER2, the Department of Energy's southwest regional standard.
• New systems built with components made in 2025 or later use one of the newer, lower-GWP refrigerants. What the refrigerant change means.
• If you heat with gas and the furnace is also old, price a heat pump too. It replaces both. Heat pumps in Stockton.

Before you sign

• Get the equipment model numbers, the SEER2 rating and the refrigerant type in writing.
• Ask whether the price includes the permit, the field test and any duct sealing the test may require.
• California caps the down payment at $1,000 or 10 percent of the contract price, whichever is less, according to the CSLB.
• Check the contractor's C-20 license on the CSLB site.
• Lodi Electric Utility customers: check its rebate application for central AC and heat pumps before you sign.