Heat Pump Installation and Repair in Sunnyvale, CA

A Homeowner’s Guide to Heat Pump Installation and Repair in Sunnyvale

Sunnyvale’s AC-to-heat-pump reach code

In August 2025 the City Council approved reach codes for alterations to existing single-family homes, and the City says enforcement will begin at the end of 2026. For heating and cooling, the draft ordinance in the Council report reads like this: when an air conditioner is installed or replaced, the altered system must do one of two things.

• Heat pump path: a heat pump becomes the primary heating source, sized to the Energy Code’s system selection rules. A gas furnace or electric resistance heat may remain as supplemental heat.
• Efficiency path: the new AC comes with sealed ducts (10% leakage, or a smoke test where that can’t be met), 300 CFM per ton of airflow and fan efficacy of 0.45 W/CFM or better, refrigerant charge verification, R-49 attic insulation and air sealing of the ceiling, each with its own exceptions.

The City’s summary of compliance requirements lists no local requirements beyond the state’s for a heat pump on existing ducts; the AC route adds fan efficacy, attic insulation and air sealing. Two exceptions send a home back to the efficiency path: a panel that can carry an AC but not a heat pump, or a heat pump that would need to be 12,000 Btu/h or more larger than the AC.

Permits and the condenser handout

Sunnyvale’s handout for residential air conditioning condenser units applies to permits submitted on or after January 1, 2026. It says a permit is required to install or replace an outdoor unit, and most can be issued online. Expect these items:

• Site plan showing property lines, buildings and the unit’s setbacks to each line.
• HOA approval letter, if the home has an association.
• Roof units: structural calculations, attachment details and roof screening.
• Final inspection once work is done, with the rater’s duct test report.

The handout also asks for a disconnect within sight of the unit, a GFCI-protected service receptacle within 25 feet, condensate drained to landscaping or a sewer tail piece, a 3-inch slab or approved platform, a locking refrigerant cap and 5 feet of clearance from a dryer vent. Questions go to the One-Stop Permit Center at 408-730-7444.

Where the outdoor unit can go

A heat pump’s compressor runs on winter nights as well as summer afternoons, so Sunnyvale’s night limit matters most. Section 19.42.030 caps noise at 50 dBA from 10 p.m. to 7 a.m. and 60 dBA from 7 a.m. to 10 p.m., measured anywhere on adjacent residentially zoned property. Setbacks follow the zoning district:

• Rear: 10 feet minimum on residential lots.
• Side: 4 feet in R-0, R-1.5 and R-2; 6 feet in other residential zones.
• Corner lots: 9 feet along the longer street frontage.

Units are screened on all four sides. A variable-speed unit, placed away from a neighbor’s bedroom window, makes the 50 dBA limit easier to meet.

What the state checks on a changeout

The California Energy Commission’s 2025 Energy Code guidance sets these checks:

• Ducts: altering a system, even swapping only the indoor or outdoor half, triggers duct sealing: 10% total leakage or 7% to outside, or a smoke test of accessible leaks.
• Refrigerant charge: verified on new heat pumps in every climate zone.
• Load calculations: required for new systems.
• Old refrigerant: recovered by a technician with an EPA 608 Type II or Universal certificate.

Since January 1, 2026, the state’s Energy Code Compliance (ECC) Program has replaced the HERS program for this testing, and HERS raters are recognized as ECC-Raters; Sunnyvale’s handout still says “HERS rater.” Results go into an ECC-Provider registry, and the paperwork stays with the home. If testing finds leaks, see duct repair.

Rebates and the furnace rule

Silicon Valley Clean Energy supplies Sunnyvale’s electricity and runs its Home Rebates. Its heat pump HVAC rebate covers ducted and ductless systems that replace a gas furnace or electric resistance heat; income-qualified customers receive more. The City of Sunnyvale adds its own rebate when a heat pump replaces a gas furnace, while City funds last. SVCE also has add-ons for a space heating circuit and for panel work up to 100 amps (200 amps by exception, with the contractor’s load calculation). TECH Clean California’s single-family heat pump incentives have been fully reserved since November 14, 2025. See SVCE heat pump rebates.

The Bay Area Air District’s Rule 9-4 applies a zero-NOx standard to residential and commercial furnaces manufactured after January 1, 2029. Rooms the ducts don’t reach can take a ductless mini-split. For Sunnyvale’s water and sewer facts, see plumbing in Sunnyvale.

Sources

City of Sunnyvale: Permits · Residential Air Conditioning Condenser Units · Electrify Your Home · Rebates · Report to Council 25-0762 (Aug. 12, 2025) with its draft ordinance and summary of compliance requirements. Silicon Valley Clean Energy: Home Rebates · Appliance Specifications (April 2026). California Energy Commission: 2025 Single-Family HVAC · Energy Code Compliance Program. Bay Area Air District: Building Appliances Rule Implementation. TECH Clean California incentives. Checked October 2026.