Frequently Asked Questions

We run a full documented diagnostic — refrigerant charge, electrical readings, airflow, and combustion where applicable — before we recommend anything. Many companies quote a repair based on a quick visual check. If our findings differ from another estimate, ask to see their measured readings; we're happy to show you ours in writing.

Every diagnostic visit produces a written report covering the readings we took (refrigerant pressures, electrical draw, temperature split, combustion analysis where applicable), what those readings indicate, and a plain-language explanation of the failure — before we quote any fix.

Your HVAC Health Report scores key system indicators — airflow, refrigerant charge, electrical health, and efficiency trend — against manufacturer specs and your system's service history, with a plain-language summary of what needs attention now versus what to monitor.

Most single-component AC repairs (capacitor, contactor, refrigerant leak repair, blower motor) fall between $150 and $900 depending on the part and labor involved. We give you the exact number in writing after diagnosis, never before.

Diagnostic visits for existing equipment problems carry a standard diagnostic fee, which is credited toward the repair if you move forward. Installation estimates for new systems are free.

Whole-home duct cleaning typically ranges depending on the number of vents and system accessibility. We inspect first and only recommend cleaning when it's actually warranted — some systems don't need it.

As a rule of thumb, if the repair cost exceeds 30-40% of a new system's cost and your unit is past 12-15 years old, replacement usually wins on long-term value. We calculate this specifically for your system on our Repair vs. Replace page and every applicable service call.

Most central AC systems last 12-18 years with regular maintenance, though Central Valley heat can shorten that range if a system is undersized or poorly maintained. Refrigerant type also matters — older R-22 systems are increasingly costly to service.

Yes. We offer financing options for qualified homeowners covering new system installations, with terms that vary based on credit approval and the lender you select. See our Financing page for current program details.

California offers rebates through programs like TECH Clean California for qualifying heat pump installations, and utility providers periodically offer their own incentives. Availability and amounts change — see our Rebates page for currently verified programs, or ask us directly during your estimate.

Standard 1-inch filters should be changed every 30-60 days, more often during wildfire smoke season or if you have pets. Thicker media filters (4-5 inch) typically last 6-12 months.

We recommend two visits per year: one for the AC system in spring and one for the heating system in fall. This catches most failures before they become emergencies during extreme weather.

A maintenance plan typically pays for itself by catching small issues (a failing capacitor, a refrigerant leak) before they cause a full breakdown, plus most plans include priority scheduling during peak season when appointments are hardest to get.

This is almost always a duct design or airflow balancing issue, not an equipment problem. Common causes include undersized ducts to that room, closed or damaged dampers, or the room being far from the air handler. We diagnose airflow room-by-room rather than guessing.

Frozen evaporator coils are usually caused by restricted airflow (dirty filter, closed vents, dirty coil) or low refrigerant charge. Running a frozen system continues to cause damage — turn it off and call us rather than waiting it out.

A straightforward single-system replacement typically takes 4-8 hours in one day. Jobs requiring ductwork modifications, electrical panel upgrades, or zoning additions can take 1-3 days.

Correct sizing comes from a Manual J load calculation, not square footage alone — insulation, window count and orientation, ceiling height, and local climate all factor in. An oversized unit cycles too often and cools poorly; an undersized one runs constantly and still can't keep up.

A brief burning-dust smell the first time you run your furnace each season is normal — it's dust burning off the heat exchanger. If the smell persists beyond 15-20 minutes or you smell gas, turn the system off and call us immediately.

A furnace generates heat by burning gas or using electric resistance. A heat pump moves existing heat from outside air into your home (and reverses to cool in summer). Heat pumps are typically more efficient in our climate but the right choice depends on your electrical setup and usage patterns.

A dirty flame sensor or failed ignitor are the most common culprits, followed by a clogged filter that trips the high-limit safety switch. Both are easy to catch with fall maintenance before winter demand starts.

Signs include rooms that never reach set temperature, unusually high utility bills, dust accumulation near vents, and visible gaps at duct joints in the attic. A pressure test gives a definitive answer — we offer this as part of our duct inspection service.

Most systems are compatible, but heat pumps, dual-fuel systems, and multi-zone setups need specific wiring and thermostat logic. We verify compatibility before recommending a specific model.

Yes — setting your thermostat fan to 'On' instead of 'Auto' will circulate air continuously without heating or cooling, which can help even out temperatures room to room, though it does use more electricity.

Yes — a thermostat with failed wiring, a dead battery, or incorrect system-type settings can prevent your equipment from receiving any call for heat or cool, even though the equipment itself is fine.

Common causes include an aging or oversized/undersized system, leaky ductwork, poor attic insulation, a dirty filter restricting airflow, or a refrigerant charge that's drifted from spec. We can run a documented efficiency diagnostic to pin down the specific cause.

SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency — higher numbers mean lower operating cost per ton of cooling. California's current minimum is SEER2 14.3 for most systems; higher-efficiency units cost more upfront but can pay back the difference in Central Valley's long cooling season.

Yes, we offer priority emergency dispatch for true no-cool or no-heat situations during extreme weather. Call our main line and identify it as an emergency.

Yes — gas furnaces, heat pumps, electric resistance heat, and dual-fuel hybrid systems are all within our service scope.

Yes. United Heating & Air operates under California Contractor License #1130646, and our technicians are trained and vetted before they're dispatched to a customer's home.

New installations carry manufacturer parts warranties (typically 10 years with registration) plus our workmanship warranty on the installation itself. Specific terms vary by equipment brand and model — we review exact coverage during your quote.