Repair or replace: the decision table
| Situation | Lean | Why, with the source |
|---|---|---|
| A part fails (igniter, capacitor, blower motor) and the system otherwise runs | Repair | Waco, for one, exempts "minor mechanical (heating/cooling/ventilation) repairs, including the routine replacement of filters" from permits (City of Waco); a replacement means a permit, an inspection and a filed value like those in the table below |
| The repair quote is a large share of a replacement | Get a replacement quote too | Compare it with your area's usual filed value and the middle half of firms in the table; a quote far outside that band is a question to ask |
| Bay Area gas furnace still works | Repair is allowed | BAAQMD: the rules "apply only upon burn out of one's current equipment"; the furnace compliance date is 2029 |
| Bay Area gas furnace has died, 2029 or later | Replacement will have to meet the zero-NOx standard | Same page; in practice that points to a heat pump or electric heat. Check the date again before you buy, since the District is amending the water-heater rule now |
| You also want cooling | Replace with a heat pump | In Marin, permits naming a heat pump or mini-split were filed at about $19,500, furnace-only permits at about $10,000 (descriptions, counted by us) |
| Your city requires a permit even to repair | Repair with a permit | Elk Grove's policy B-20-35 covers anyone who would "repair, remove, convert or replace any electrical, gas, mechanical or plumbing system" |
We found no official source for how many years a furnace or AC unit lasts, so this page gives no age rule.
What a replacement is filed at, city by city
"Usual filed value" is the middle job value contractors wrote on HVAC permits; "middle half of firms" is the range of usual job values for the middle half of firms with three or more permits; "finished" is the share of permits a year or more old that reached final; "days to final" counts open permits as unfinished. A dash means the place does not record that field.
| Place | Permits | Usual filed value | Middle half of firms | Finished | Days to final |
|---|---|---|---|---|---|
| Marin County, CA (unincorporated) | 1,640 | $13,261 | $14,000–$19,250 | 74.8% | 96 |
| Sacramento County, CA (unincorporated) | 7,937 | $15,268 | $10,000–$15,950 | 84.1% | 56 |
| Elk Grove, CA | 4,434 | $16,000 | $11,775–$16,906 | 84.7% | 50 |
| Citrus Heights, CA | 2,212 | $14,853 | $10,400–$16,360 | 81.7% | 62 |
| Palo Alto, CA (HVAC and heat pumps) | 938 | $13,018 | $11,273–$19,785 | — | 69 |
| Seattle, WA (furnace and heating) | 18,668 | $7,550 | $6,500–$14,000 | 86.2% | 66 |
| Seattle, WA (heat pump and AC) | 15,441 | $8,000 | $6,000–$15,000 | 85.6% | 105 |
| Boulder, CO | 4,460 | $10,572 | $7,750–$15,000 | 70.2% | 76 |
| Cary, NC | 9,909 | $9,891 | $7,900–$11,693 | 77.9% | 29 |
| Miami, FL | 5,161 | $6,792 | $5,250–$10,000 | 95.6% | 73 |
| Arlington, VA | 2,807 | $8,600 | $4,000–$12,320 | 86.9% | 148 |
| Cincinnati, OH | 5,741 | $8,365 | $5,400–$11,891 | 66.8% | 278 |
| Wheaton, IL (heating and cooling) | 1,060 | $9,578 | $8,424–$11,297 | 47.3% | 398 |
The five California places file higher than the rest. Our reading, which the file cannot confirm: more of their permits are heat pumps or furnace-plus-AC systems, as Marin's descriptions suggest below. Compare a quote with firms in its own place, not across places. Wheaton's file is the outlier on timing: 47.3% finished and a usual 398 days, so an open HVAC permit there is normal for months.
What Marin's permit descriptions say
Of the 1,640 HVAC permits on homes in unincorporated Marin, 530 name a heat pump or mini-split and were usually filed at about $19,500; 577 name a furnace and no heat pump, usually filed at $10,000; 934 use the words "replace", "change out" or "like for like" (our count from the County's permit descriptions, snapshot 19 October 2026). So more than half of Marin's HVAC permits describe a replacement, and the heat-pump jobs file at about twice the furnace-only ones. Furnace-only permits closed at about the same rate as heat-pump ones (74% against 73% of those a year or more old), so the choice does not change how likely the permit is to reach final.
88.5% of Marin's HVAC firms matched an active CSLB license by name; the busiest over the last twelve months was Ernest Ongaro & Sons Inc with 93 permits.
See every Marin County HVAC firm by filed value and finished share →
Which jobs need a permit (replacements do, most repairs don't)
- Waco, Texas: "Heater or air conditioning unit installations or changeouts, including ductwork, exhaust fans" need a residential mechanical permit; "minor mechanical (heating/cooling/ventilation) repairs, including the routine replacement of filters" do not (City of Waco, read 21 October 2026).
- Elk Grove, California: policy B-20-35 requires a permit to "erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system", with an emergency replacement application due "within the next working business day" (City of Elk Grove, read 20 October 2026). That wording reaches repairs too.
Two cities, two rules. Before a big repair, ask the building counter whether it needs a permit, and get the answer by email.
Rules that decide it in the Bay Area
The Bay Area Air Quality Management District's Rules 9-4 (furnaces) and 9-6 (water heaters and boilers) set zero-NOx standards for new equipment, with dates "beginning in 2027, 2029, and 2031, depending on size and equipment type": 2027 for water heaters, 2029 for furnaces. The District describes them as "point of sale emission standards" that "apply only upon burn out of one's current equipment". In October 2026 its staff proposed flexibility amendments to Rule 9-6 for small water heaters (under 75,000 BTU an hour), including some exemptions and a later compliance date; the Board takes them up on 4 November 2026 (BAAQMD, page updated 9 October 2026, read 21 October 2026). Those are proposals, not rules yet. Marin County is inside the District; outside the Bay Area, ask your own air district.
Incentives in 2026
No federal credit: the IRS says the energy efficient home improvement credit (25C) cannot be claimed for property placed in service after 31 December 2025 (Form 5695 instructions). In Sacramento County, SMUD pays "up to $3,000 for gas-to-electric heat pump HVAC system conversions" and $1,000 for electric-to-electric heat-pump HVAC upgrades, from February 2026 (SMUD, 18 February 2026). A repair earns neither.
What this does not tell you
The permit file records replacements and some repairs, not service calls, so we cannot say what a repair costs or how often repairs come before a replacement. Filed value is the contractor's figure on the application, not your bill, and it excludes a separate electrical permit for a panel upgrade. Marin's heat-pump and furnace split comes from free-text descriptions and misses permits that name neither. License status is matched by business name; an unmatched firm is not necessarily unlicensed.
How we know this
Source: each place's open building-permit data, HVAC permits on homes classified by us from the permit type and description, window October 2023 to September 2026, snapshots 14 to 19 October 2026. Fields: permit count, filed job value (usual = middle value), middle half of firms' usual values (firms with 3+ permits), finished share of permits 365+ days old, issue-to-final days with open permits counted as unfinished. Marin's heat-pump, furnace and replacement counts were computed by us from the County's permit descriptions (words "heat pump", "mini-split", "furnace", "replace", "change out", "like for like"). Rules are quoted from BAAQMD, the City of Waco and the City of Elk Grove; incentives from the IRS and SMUD; pages read 20 and 21 October 2026.
Numbers come from Marin County Community Development Agency building permits on homes in unincorporated Marin (the County's open-data permit and inspection files); Sacramento County building permits on single-family, duplex and townhouse homes in the unincorporated county (the County's Accela permit layer); City of Citrus Heights building permits on homes (the city's issued-permits layer); City of Elk Grove TRAKiT building permits on single-family, duplex, mobile-home and ADU homes; City of Palo Alto Development Center building permits on single-family, duplex and ADU homes; City of Seattle (SDCI) building, trade and electrical permits on single-family and duplex homes (the city's open-data exports); City of Wheaton permits on homes (the city's permit application and inspection exports), data through October 19, 2026. Nobody paid to be on this page and nobody can.
See every Sacramento County HVAC firm →
Questions
- Do I have to replace my working gas furnace in the Bay Area?
No. The Bay Area Air Quality Management District says its zero-NOx appliance rules "apply only upon burn out of one's current equipment". The furnace standard has a 2029 compliance date and the water-heater standard 2027; a change to the small water-heater rule goes to the District's Board on 4 November 2026.
- What does an HVAC replacement cost in Marin County?
The usual HVAC permit in unincorporated Marin was filed at $13,261 (1,640 permits, October 2023 to September 2026). Permits that mention a heat pump or mini-split were usually filed at about $19,500; furnace-only permits at about $10,000 (our count from the permit descriptions). Filed value is what the contractor wrote, not the invoice.
- Does an HVAC repair need a permit?
It depends on the city. Waco says routine filter changes and minor repairs need none but any heater or AC changeout does. Elk Grove's policy requires a permit to "repair" or "replace" any mechanical system. Ask your building counter before a large repair, because a repair done without a needed permit leaves nothing on the record.
- When should you replace your HVAC system vs. repairing it?
ENERGY STAR's guide: consider replacing a heat pump or air conditioner once it is more than 10 years old and a furnace or boiler at more than 15, or sooner if it needs frequent repairs while bills rise or some rooms stay too hot or cold. Younger equipment with one failed part is a repair. A replacement was usually filed at $15,268 in Sacramento County.
- Is there a federal tax credit for a new heat pump or furnace in 2026?
No. The IRS instructions for Form 5695 say the energy efficient home improvement credit cannot be claimed for property placed in service after 31 December 2025.
- How do I check the HVAC contractor?
In California, look the license number up on CSLB's Check a License page and confirm the C-20 classification. Then open the firm on our HVAC list for your city and compare its usual filed value and finished share with the city's.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- How long does an HVAC system last? Furnace, AC and heat pump lifespans, and when to replace
- Heat pump vs furnace: what Seattle homeowners filed
- How to check a contractor's license in California
- Hiring an HVAC contractor: 5 red flags and 10 questions, checked against HVAC permits in 43 cities
For one city
- Rules 9-4 and 9-6 Building Appliances — Bay Area Air Quality Management District (last updated 9 October 2026) (2026-10-21)
- Do I Need a Permit? — City of Waco Inspection Services (2026-10-21)
- Do I need a building permit? Policy B-20-35 (City of Elk Grove, CA) (2026-10-20)
- Instructions for Form 5695 (2025) (IRS, last updated 30 April 2026) (2026-10-20)
- SMUD boosts rebates for heat pumps (SMUD news release, 18 February 2026) (2026-10-21)
- Check a License — CSLB (2026-10-20)
- When is it time to replace? — ENERGY STAR (U.S. EPA) (2026-10-22)