4.9/5 — 2,000+ Five-Star Reviews
Emergency AC Repair in Cupertino
24/7, Based In Your City
AC down in a heatwave? Our main office is on Pineville Avenue in Cupertino, so we are already in your city rather than driving over from another one. We answer the phone 24/7, quote a flat price before starting, and carry the common failure parts on the truck.
- 25+ Years
- Licensed & Insured
- 24/7 Emergency
- No hidden costs
- Same-day service
- Fully licensed and insured
- 6000+ completed jobs
4.9/5 Rating
2,000+ Reviews
Licensed & Insured
CA Licensed
Same-Day Service
24/7 Emergency
25+ Years
Bay Area Experts
6,000+
Jobs Completed
Simple Process
How It Works
Call Us 24/7
Reach us anytime at
(408)539-6936.
Same-Day Dispatch
A licensed technician arrives at your home, often same day.
Diagnose & Fix
Upfront pricing before work begins. No hidden fees, ever.
100% Satisfaction
We stand behind every job with our satisfaction guarantee.
24/7 Air Conditioning Repair in Cupertino
Emergency Air Conditioning Repair in Cupertino
For emergency AC repair in Cupertino, our main office and warehouse are at 10531 Pineville Avenue — inside the city. That is the whole reason we can promise realistic response times here rather than a two-day window — the truck is already in town.
We cover every part of the city: Monta Vista, Rancho Rinconada, Garden Gate, Oak Valley, Seven Springs, Inspiration Heights, Fairgrove and the neighbourhoods around De Anza and Homestead. Every job carries California contractor license #1061226 and $2 million in liability insurance, and every technician is background-checked.
Why Air Conditioning Fails in the First Real Heatwave
Almost every emergency call we take in Cupertino arrives in the same forty-eight hours — the first genuinely hot spell of the year. The system sat unused for eight months, then ran flat out, and whatever was marginal finally gave up. The usual culprits:
- Failed capacitor. The single most common summer failure. The fan hums but the compressor will not start, or the unit trips the breaker. It is an inexpensive part and a same-visit fix — if the technician is carrying one.
- Refrigerant loss. The system blows air but not cold air, and ice forms on the line. Refrigerant does not get consumed, so low charge always means a leak; topping it up without finding the leak just books you a repeat call next summer.
- Seized condenser fan motor. Common on units that have sat through a decade of Cupertino summers. The compressor overheats and shuts down on its safety.
- Frozen evaporator coil from a blocked filter. Airflow drops, the coil ices over, and the system stops cooling entirely. Genuinely the cheapest problem on this list and the most preventable.
- Undersized or ageing systems in the 1950s and 60s tracts. Much of Cupertino was built between 1955 and 1975, and plenty of that housing stock is running equipment that was marginal when it was new.
What to Do Before We Arrive
Switch the system off at the thermostat rather than letting it keep trying — running a unit with a frozen coil or a failing compressor causes real damage. Check the filter, and check the breaker. If the coil is iced, turning the system off and the fan on will thaw it, which usually takes a couple of hours and often gets you cooling back before we arrive.
What We Handle
- 24/7 emergency AC repair — nights, weekends and through heatwaves.
- Capacitors, contactors, fan motors and control boards.
- Refrigerant leak detection and recharge — finding the leak, not just refilling.
- Compressor diagnosis and honest repair-or-replace advice.
- Complete AC and heat-pump replacement when the unit is past saving.
- Ductless mini-splits for the Fairgrove Eichlers and other homes without ductwork.
- Pre-summer maintenance — the reason some houses on your street never make this call.
Repair, or Replace?
A unit under about ten years old with a failed capacitor, contactor or fan motor is worth repairing without hesitation. Once a compressor has failed on a system in its mid-teens, the repair often approaches the cost of a new unit that will run at far lower cost — and heat-pump replacements in Cupertino are supported by Silicon Valley Clean Energy programmes worth checking before you commit. We will give you both numbers rather than just the one that suits us.
Upfront Pricing, No Trip Charge
You get a flat written price before anything is touched, including on an emergency call-out — we do not price by how desperate the weather has made you. Estimates are free and there is no trip charge in Cupertino.
No cooling right now?
Call (408) 539-6936. We are based in Cupertino and we answer 24/7.
100% Satisfaction Guarantee
If you're not completely satisfied with our work, we'll come back and make it right — free of charge. That's our promise to every customer.
Signs You Need Emergency AC Repair in Cupertino
- System not functioning properly
- Increased energy bills
- Planned upgrades or renovations
- Unusual noises or odors
- Age-related wear and tear
- Water leaks or damage signs
Reviews
What Our Customers Say

Pasha (technician) was very helpful. We had a clogged drain and were unable to clear it ourselves. He arrived and fixed the drain and was very clean and polite. Left everything as it was before he arrived. Highly recommend.
Pasha was very professional, he gave us a couple of options and finished the plumbing job very quickly.
As a busy homeowner I truly appreciate their ability to work around my schedule and needs. My garbage disposal recently died, and Neo was professional and offered me different options. He had the parts I needed and was able to complete the job quickly and cleanly.
Why Choose United HVAC
- 25 years of experience
- Same-day service
- 1+ year warranty
- 6000+ completed jobs
- 0% interest financing and discounts
- Fully licensed and insured
- Well reviewed and highly trusted
- No hidden costs
- We work 365 days a year
Got Questions?
Frequently Asked Questions
Our main office and parts warehouse are at 10531 Pineville Avenue, inside Cupertino, so we are not dispatching from another city. We answer the phone 24/7 and prioritise complete cooling failures during heatwaves. Common failure parts — capacitors, contactors, fan motors — are on the truck, so most emergency calls are fixed on the first visit.
Usually one of three things: a failed capacitor stopping the compressor from starting, low refrigerant from a leak, or a frozen evaporator coil caused by a blocked filter. Switch the system off at the thermostat so it stops trying — running it in this state can turn a cheap repair into an expensive one.
No, and it means stop. Ice forms when airflow drops or refrigerant is low. Turn the cooling off and the fan on; the coil will thaw in a couple of hours. Then check the filter. If it ices again after a clean filter, it is a refrigerant leak and needs a technician.
You get a flat written price before we start, and we do not raise it because it is a Sunday in a heatwave. Estimates are free and there is no trip charge in Cupertino.
No. Refrigerant is not consumed — it circulates in a sealed loop. If it is low, there is a leak. Topping up annually means paying repeatedly to leak refrigerant into the atmosphere while the underlying fault gets worse. We find and fix the leak instead.
All of them — Monta Vista, Rancho Rinconada, Garden Gate, Oak Valley, Seven Springs, Inspiration Heights, Fairgrove and the streets around De Anza and Homestead. No trip charge anywhere inside the city.
Yes. Eichlers have flat roofs and no attic, so ducted systems are not an option. A ductless mini-split, single or multi-zone, is the standard solution, with heads placed to preserve the clean lines the houses are known for.
It depends on age. Under about ten years, repair usually makes sense. Mid-teens or older, a compressor replacement often approaches the cost of a new system that runs far cheaper — and heat-pump replacements here are supported by Silicon Valley Clean Energy programmes worth checking first. We will give you both figures.
Pre-summer maintenance, honestly. Nearly every emergency call we take arrives in the first hot forty-eight hours of the year, on systems that sat idle for eight months. A spring check catches the weak capacitor and the low charge before the heat does.
Yes. California contractor license #1061226, $2 million in liability coverage, and every technician is background-checked. The license number appears on your quote.
Related Services
Other HVAC Services
Air Conditioner Installation
Expert air conditioner installation for maximum comfort and energy efficiency.
Air Conditioning Repair
Fast, reliable AC repair to restore your cooling system and keep your home comfortable.
Air Conditioning Maintenance
Preventive AC maintenance to extend system life and prevent costly breakdowns.
Heating System Installation
Professional heating system installation for year-round warmth and reliability.
Heating Repair
Fast heating repair services to restore warmth to your home when you need it most.
Heating Maintenance
Scheduled heating maintenance to keep your system running safely and efficiently.
Heat Pump Installation
Energy-efficient heat pump installation for year-round heating and cooling.
Heat Pump Replacement
Professional heat pump replacement with modern, high-efficiency units.
Mini Split Installation & Repair
Ductless mini split installation and repair for flexible zone-based climate control.
Air Filter Installation & Replacement
Air filter installation and replacement to improve air quality and keep your HVAC system running efficiently.
Air Scrubber Installation & Maintenance
Air scrubber installation and maintenance to remove airborne contaminants and enhance indoor air quality throughout your home.
Explore Our Other Services
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10 services available
Drain & Sewer
4 services available
Water Heating & Filtration
4 services available
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4 services available
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Electrical Services
6 services available
Posted on Google Omied LeleTrustindex verifies that the original source of the review is Google. Pasha (technician) was very helpful. We had a clogged drain and were unable to clear it ourselves. He arrived and fixed the drain and was very clean and polite. Left everything as it was before he arrived. Highly recommend.Posted on Google Liang KatherineTrustindex verifies that the original source of the review is Google. Fantastic service! We really enjoyed working with United plumbingPosted on Google Natalia ShreveTrustindex verifies that the original source of the review is Google. Pasha was very professional he gave us a couple of options and finished the plumbing job very quicklyPosted on Google Just JaniceTrustindex verifies that the original source of the review is Google. As a busy homeowner I truly appreciate their ability to work around my schedule and needs. My garbage disposal recently died, and Neo was professional and offered my different options. He had the parts I needed and was able to complete the job quickly and cleanly.Posted on Google Chaozhong LianTrustindex verifies that the original source of the review is Google. I wholeheartedly recommend United HVAC, Plumbing & Electrical. I recently hired them to replace the original 1961 HVAC ductwork in my house, and they did a wonderful, extremely professional job. I am beyond satisfied with the results. You don't just have to take my word for it--I actually took pictures of their completed work, uploaded them to Google Gemini, and asked the AI to evaluate the installation. Even the AI praised their work, calling it a "top-tier, textbook installation"! (See the screenshots below). During the bidding process, I compared United with another company. United's quote was slightly higher, but choosing them was absolutely the best decision. Their program manager, Tim, was incredibly easy to work with. He quickly identified asbestos tape on my 1961 ducts and insisted we use a C-22 licensed abatement company to remove it safely and provide all the legal documentation for future reference. The other company offered a cheaper route by doing the removal themselves, but for something as dangerous as asbestos, doing it by the book is well worth the minor price difference. I also want to give a massive shoutout to Bair (Bayar) for his exceptional craftsmanship. He is easy-going, friendly, and really listened to all of my concerns. He provided great recommendations on how the new ductwork should be organized, and actually used a machine to fine-tune and balance the air pressure throughout the house. To top it all off, he even carefully reorganized the insulation in my attic after the work was done! It's this kind of attention to detail that makes them stand out. The pictures speak for themselves. If you want true professionals who care about safety, honesty, and quality craftsmanship, go with United HVAC.Posted on Google Chaozhong LianTrustindex verifies that the original source of the review is Google. I highly recommend United HVAC, Plumbing & Electrical! From start to finish, the entire process was incredibly smooth. They handled all the permits and inspections throughout the project, which gave us complete peace of mind. Every single technician we interacted with was friendly, approachable, and truly easy to work with. I specifically want to give a massive shoutout to Max (Aiusha) and Rinat for their wonderful work. Max is super professional and highly skilled. He installed my water heater and water softener with absolute "military precision." I'm the kind of guy who has a lot of weird, specific ideas about how pipes should be routed and extra gadgets I want installed to monitor the system, and Max handled all my requests with total ease. I am also super paranoid about plumbers plowing through studs or structural beams in my 1961 house, but Max was extremely careful and treated my home's structure with the utmost respect. Rinat is also a fantastic plumber. He installed a PRV, a Moen Flo auto-shutoff valve, an RO system, and even replaced some of the old sewage pipes in my house. He really listened to all of my requests and finished the job quickly and professionally. I highly recommend him! Because of their wonderful service, I’ve officially signed up for their company's membership. I am currently working with them to redo my HVAC ductwork, and I will definitely leave another review for that project once it's done. I'm sure they will do a wonderful job there, too!Posted on Google Ritesh BediaTrustindex verifies that the original source of the review is Google. Great service. Loved the professionalism and the way fixed my plumbing problem. I would call them again.Posted on Google Ginger PerngTrustindex verifies that the original source of the review is Google. We had to replace the wax ring on our toilet. Scheduling was easy; pricing was fair (much cheaper than the other quote we got!) Our technician, Melvin, was polite and expedient. This is our second time using United and highly recommend for gas and plumbing services.Posted on Google Joseph MartinTrustindex verifies that the original source of the review is Google. Melvin was great. Fast and efficient.
Serving the Bay Area
Emergency AC Repair in Cupertino Available In
We proudly serve homeowners across the entire Bay Area
Don’t see your city? Call (408)539-6936 to check availability.