What AC Replacement Really Costs in the Tri-Valley

By Andrew Kuznetsov, a licensed Bay Area contractor (CSLB #1136642, C-20, EPA 608), for the Tri-Valley homeowner’s guide.

If you’ve started pricing a new central air conditioner for a home in Pleasanton, Livermore, Dublin, San Ramon, or anywhere in the inland East Bay, you’ve probably noticed the quotes are all over the map. One contractor says one thing, the next says something very different, and neither number looks like the article you read online. That’s normal. AC replacement isn’t a fixed-price product. It’s a custom job, and the price reflects your specific house.

This guide walks through what actually moves the number, so you can read your estimates with a clear head instead of guessing who’s fair.

Why the quotes vary so much

A few real things drive the cost, and most of them have nothing to do with the brand badge on the box.

• System size (tonnage). Cooling capacity is measured in tons. A bigger or poorly insulated house needs more capacity. A good contractor sizes it with a load calculation, not by copying whatever was there before.
• Efficiency (SEER2). Higher-efficiency units cost more up front. Given how long our cooling season runs out here, a more efficient system can pay some of that back on summer electric bills, but the gap isn’t always worth it. Ask for the math.
• Ductwork condition. This is the quiet budget-buster. If your ducts are leaky, undersized, or crushed in the crawlspace, that work gets added on. Old homes with original ducting often need repairs the brochure never mentions.
• Electrical. A new high-efficiency unit, or a switch to a heat pump, sometimes needs a panel upgrade or new circuit. That’s a separate line that can swing a quote hard.
• Refrigerant rules. The industry has moved off R-410A toward newer low-GWP refrigerants. Equipment using the newer stuff can price differently, and mixing old and new components isn’t allowed. If a quote is unusually cheap, ask what refrigerant the equipment uses.
• Access and disposal. A rooftop unit, a tight side yard, or a furnace buried in a cramped attic all add labor. Hauling away and properly disposing of the old equipment is real work too.
• Permit. Replacing central AC in California requires a permit and an inspection. It’s not optional, and a legitimate contractor builds it into the quote. A bid that skips the permit isn’t saving you money, it’s skipping a step.

Because every one of these varies house to house, two honest contractors can land far apart and both be right.

Rough 2026 ballparks (and why you still need real quotes)

Take these as very loose orientation, nothing more. Actual numbers in 2026 vary a lot by home, equipment, and how much duct or electrical work comes along for the ride.

I’m deliberately not putting a single dollar figure here, because any precise number I gave you would be wrong for most homes. The only way to know your real cost is to get two or three written, itemized quotes and compare the line items, not just the bottom line. Look at whether each bid includes the permit, the duct work, disposal, and a load calculation. That’s where the honest differences show up.

Repair or replace?

If your system is under roughly ten years old and the fix is a capacitor or a contactor, repair usually wins. Replacement starts making sense when the unit is well into its teens, the repair is a major part like a compressor, or it still runs on older refrigerant that’s getting expensive to source. A string of repairs in back-to-back summers is its own signal. If your AC just isn’t keeping up, start with why an AC stops cooling before you assume the whole thing is done, and the same repair-versus-replace logic that applies to big home appliances applies here too.

Worth pricing a heat pump instead

While you’re getting quotes, it’s worth asking each contractor to price a heat pump alongside the straight AC swap. A heat pump cools in summer and heats in winter, so it can replace both your AC and your furnace. The up-front cost is often higher, but rebate and incentive programs can offset a meaningful chunk, and you end up with one system instead of two. Our long cooling season and mild winters suit them well. There’s more on the tradeoffs in the guide to heat pumps.

Permits and rebates

The permit isn’t just red tape. The inspection is what confirms the work was sized and installed correctly, which matters if you ever sell the house. Rebates can also knock down the net cost of a more efficient system or a heat pump, and the programs change, so check current offers before you sign. Start with the regional BayREN program and ENERGY STAR, and see the local notes on rebates and permits.

Before you sign anything

Verify the contractor’s license on the CSLB website (you want a C-20 HVAC classification), and confirm they handle refrigerant under EPA Section 608 rules. The how to hire a repair tech guide covers what a clean, comparable bid should include, and the local resources page points to utility and permit contacts for your city.

If you’d rather start with a name, ADRIUM Service Solutions is a San Ramon-based licensed company (CSLB #1136642, C-20, EPA 608). Get a couple of other written quotes alongside it so you have something to compare. Or, if you’d rather skip the search entirely, get matched with a vetted local tech for your town, no obligation. For more on keeping a new system healthy once it’s in, see seasonal maintenance.