Furnace replacement in Los Angeles is as much about compliance as it is about comfort. Day to day, we design to code, pull permits, commission new systems, and assemble closeout packets that include model and serial numbers, startup readings, a documented carbon monoxide baseline with measured monoxide levels, warranty registration, and rebate paperwork when it applies. We also track SCAQMD Rule 1111 updates and utility incentives so homeowners are not caught off guard during inspections or rebate reviews. That practical experience is the lens for this article.

What follows is a straightforward walkthrough of Ultra Low NOx requirements in Los Angeles, how to confirm a furnace is compliant, what to expect with costs and current rebates, and the commissioning checks that protect performance and safety. Let’s get started.

What is Ultra-Low NOx?

NOx basics. Nitrogen oxides (NOx) are pollutants produced during natural-gas combustion. In densely populated basins like Los Angeles, NOx contributes to smog and respiratory irritation, which is why emissions from residential furnaces are regulated.

The rule. Within the South Coast Air Quality Management District (SCAQMD), new residential gas furnaces must meet an Ultra-Low NOx limit of 14 nanograms per joule (ng/J). Older “low-NOx” models typically exceed that threshold, so they are not approved for new installations in Los Angeles County. For most homeowners, this means your replacement furnace must be explicitly labeled as Ultra-Low NOx and documented as compliant with Rule 1111.

Why it matters locally. LA’s topography and weather patterns can trap pollutants. Replacing legacy equipment with Ultra-Low NOx models meaningfully reduces regional emissions while keeping homes comfortable.

How Ultra-Low NOx affects your furnace replacement

What you can buy. When you shop for a new furnace in Los Angeles, plan on selecting a model that is certified Ultra-Low NOx under Rule 1111. Your heating and cooling contractor should provide the specification sheet and compliance documentation as part of the submittal and final closeout packet.

What it costs. Ultra-Low NOx equipment often carries a modest premium compared with legacy units. Many homeowners see that offset by higher efficiency (commonly 90%+ AFUE), better comfort from modern blower technology, and potential incentives. The net cost depends on capacity, staging (single, two-stage, or modulating), installation conditions, and ductwork.

Recommended Ultra-Low NOx furnace lines (Rule 1111 compliant)

Carrier Infinity ULN (59CU5): Variable-speed gas furnace line designed for California’s Ultra-Low NOx requirement (14 ng/J). Carrier also offers the Comfort 95 ULN (59SU5) as a value option. Verify the spec sheet for Rule 1111 language when selecting size.

Goodman GM9S96-U: Single-stage, ECM-blower, 96% AFUE models that explicitly carry the “-U” Ultra-Low NOx designation. Confirm the “U” suffix on the data plate or literature to ensure 14 ng/J compliance.

Trane L8X1 / L8V1 (California ULN): Trane’s California-specific Ultra-Low NOx furnaces (L8X1 single-stage; L8V1 variable-speed) certified to 14 ng/J under Rule 1111, with published ULN documentation. Match AFUE and airflow to your ductwork during design.

Features that matter in Los Angeles installations

For most homes, look for an Ultra-Low NOx certification label, an efficiency rating at or above 90% AFUE, and a variable-speed blower for quieter operation and steadier temperatures. Be sure your installer includes SCAQMD compliance documentation, confirms vent materials appropriate to the AFUE class, and records commissioning data such as gas pressure, temperature rise, and initial carbon monoxide readings with measured monoxide levels at supply registers.

Must-have features for Los Angeles installations:

Ultra Low NOx certification label
90% AFUE minimum efficiency
Variable speed blower technology
SCAQMD compliance documentation

Rebates and incentives

Utility and tax incentives change over time. SoCalGas and federal programs have historically offered benefits for qualifying high-efficiency equipment, and municipal utilities may run limited-time offerings. Because funding windows and amounts vary, verify eligibility, paperwork requirements (including permit closure), and deadlines before you purchase. Your contractor should help assemble model/serial confirmations, commissioning data, and any required forms.

Available incentives for LA homeowners: