Hao Wu is dedicated to providing our customers with the best quality and craftsmanship. We are here to build relationships with our customers and communities and to provide our employees with a great place to work. We look forward to working with you!
Hao Wu is dedicated to providing our customers with the best quality and craftsmanship. We are here to build relationships with our customers and communities and to provide our employees with a great place to work. We look forward to working with you!
We provide our clients with the very best in installation, service, and repair for you heating and cooling needs. Our company is built on honesty and integrity. We specialize in heating and furnace systems in addition to a variety of HVAC-related projects. We take pride in the quality of our work and our commitment to outstanding results and look forward to building long-term relationships with our clients and guarantee your satisfaction.
"Had another company come out and try to sell me a new A/C that I knew I didn't need. Hassler came out next day and fixed the problem in a matter of minutes. Thanks!"
Kevin G on May 2020
We provide our clients with the very best in installation, service, and repair for you heating and cooling needs. Our company is built on honesty and integrity. We specialize in heating and furnace systems in addition to a variety of HVAC-related projects. We take pride in the quality of our work and our commitment to outstanding results and look forward to building long-term relationships with our clients and guarantee your satisfaction.
"Had another company come out and try to sell me a new A/C that I knew I didn't need. Hassler came out next day and fixed the problem in a matter of minutes. Thanks!"
Kevin G on May 2020
Thank you for choosing 411 Heating & AC, LLC, Contra Costa Countys premiere HVAC service professional. For nearly a decade, we've specialized in all your heating and air conditioning needs. We proudly serve Concord and the surrounding areas. We look forward to earning your business.
"Our heater broke and my husband is medically fragile and It was 58 degrees INSIDE. I needed help ASAP. He's 88 and I'm 77 and calling people was frustrating until I checked top Angie reviews for my area. Even then, two out of three failed on ability to respond in less than 7-10 days. Another said we can come assess in three days and then schedule your repairs. 411 came within hours and had us heating up with a brand new, quieter, and quicker system the next day! Can't thank them enough. And the pricing was very fair based on checking with others in our neighborhood and relatives who have had to replace their systems."
Linda M on February 2025
Thank you for choosing 411 Heating & AC, LLC, Contra Costa Countys premiere HVAC service professional. For nearly a decade, we've specialized in all your heating and air conditioning needs. We proudly serve Concord and the surrounding areas. We look forward to earning your business.
"Our heater broke and my husband is medically fragile and It was 58 degrees INSIDE. I needed help ASAP. He's 88 and I'm 77 and calling people was frustrating until I checked top Angie reviews for my area. Even then, two out of three failed on ability to respond in less than 7-10 days. Another said we can come assess in three days and then schedule your repairs. 411 came within hours and had us heating up with a brand new, quieter, and quicker system the next day! Can't thank them enough. And the pricing was very fair based on checking with others in our neighborhood and relatives who have had to replace their systems."
Linda M on February 2025
With over 30 years of experience, Perfect Star Heating, Cooling, & Electrical is a locally owned and operated family business serving Alameda & Contra Costa County. We service all makes and models, offering top-quality comfort and energy efficiency solutions. Specializing in Furnace/Heating, Air Conditioning, and Ductless Mini-Split installation, we also provide repair and maintenance for Central HVAC systems, Ductwork, Indoor Air Quality, Electrical Repair & Installation, and Solar Installation. Free estimates are available for HVAC system replacement, new installations, and solar solutions. As a Lennox Premier Dealer, Daikin Comfort Pro, and WellAir Elite dealer, we are Diamond Certified, hold an A+ BBB Rating, and have been voted “The Best Heating & Air Company” and “The Most Community-Minded Company” by The Press in Brentwood, CA for two years. We are also SFGATE’s Best of the Bay Area Heating & A/C Service provider.
"Quick and well priced work. Friendly electrician who did everything in a professional manner. "
Kevin E on July 2025
With over 30 years of experience, Perfect Star Heating, Cooling, & Electrical is a locally owned and operated family business serving Alameda & Contra Costa County. We service all makes and models, offering top-quality comfort and energy efficiency solutions. Specializing in Furnace/Heating, Air Conditioning, and Ductless Mini-Split installation, we also provide repair and maintenance for Central HVAC systems, Ductwork, Indoor Air Quality, Electrical Repair & Installation, and Solar Installation. Free estimates are available for HVAC system replacement, new installations, and solar solutions. As a Lennox Premier Dealer, Daikin Comfort Pro, and WellAir Elite dealer, we are Diamond Certified, hold an A+ BBB Rating, and have been voted “The Best Heating & Air Company” and “The Most Community-Minded Company” by The Press in Brentwood, CA for two years. We are also SFGATE’s Best of the Bay Area Heating & A/C Service provider.
"Quick and well priced work. Friendly electrician who did everything in a professional manner. "
Kevin E on July 2025
At MDP, we pride ourselves on our commitment to transparency, affordability, and exceptional customer service. Our certified technicians ensure every project is completed with the utmost professionalism and care, keeping your comfort and satisfaction as our top priorities. 📞 Contact us at (669) 400-6792 📧 Email: accounting@mdphvac.com 💻 Website: https://mdpheatingcooling.com/ 📜 California License #1103720. Our services include: ✅ Furnace and heat pump diagnostics and repairs ✅ Duct cleaning ✅ Expert HVAC system installation and maintenance ✅ Thermostat installation and optimization ✅ Free second opinions on previous HVAC estimates
"Project done."
Perry C on May 2025
At MDP, we pride ourselves on our commitment to transparency, affordability, and exceptional customer service. Our certified technicians ensure every project is completed with the utmost professionalism and care, keeping your comfort and satisfaction as our top priorities. 📞 Contact us at (669) 400-6792 📧 Email: accounting@mdphvac.com 💻 Website: https://mdpheatingcooling.com/ 📜 California License #1103720. Our services include: ✅ Furnace and heat pump diagnostics and repairs ✅ Duct cleaning ✅ Expert HVAC system installation and maintenance ✅ Thermostat installation and optimization ✅ Free second opinions on previous HVAC estimates
"Project done."
Perry C on May 2025
Eagle Air has been in business since 1993 and is a recognized authority in HVAC design, installation, repair, maintenance, and replacement of residential and commercial heating and air conditioning systems. Eagle Air offers equipment and certified professional service.
"Good"
Ani B on August 2024
Eagle Air has been in business since 1993 and is a recognized authority in HVAC design, installation, repair, maintenance, and replacement of residential and commercial heating and air conditioning systems. Eagle Air offers equipment and certified professional service.
"Good"
Ani B on August 2024
DENNIS'S HEATING & COOLING is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.
"Expert, flexible, and costs are reasonable. Highly recommended!!!"
Allan G on June 2025
DENNIS'S HEATING & COOLING is committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business.
"Expert, flexible, and costs are reasonable. Highly recommended!!!"
Allan G on June 2025
AireServ of Pleasanton is a locally/owner run and operated company. We service all of East Bay Area. We are committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests and make their concerns the basis of our business. AireServ has been around for over 20-years with over 250 locations.
AireServ of Pleasanton is a locally/owner run and operated company. We service all of East Bay Area. We are committed to excellence in every aspect of our business. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests and make their concerns the basis of our business. AireServ has been around for over 20-years with over 250 locations.
With 25 years of experience C.A Heating and Air Conditioning is a leader in providing our customers with the highest quality service in an honest, efficient, and professional way. Our pledge is to create successful relationships with our customers, employees and community by building trust, treating every project with the utmost integrity and exceeding expectations. We look forward to working with you!
"“Chad was awesome! He showed up on time, was professional, and walked through different scenarios to make sure the job got done right. Really appreciated his problem-solving approach and thoroughness.” Thank you again Chad!"
shawn s on April 2025
With 25 years of experience C.A Heating and Air Conditioning is a leader in providing our customers with the highest quality service in an honest, efficient, and professional way. Our pledge is to create successful relationships with our customers, employees and community by building trust, treating every project with the utmost integrity and exceeding expectations. We look forward to working with you!
"“Chad was awesome! He showed up on time, was professional, and walked through different scenarios to make sure the job got done right. Really appreciated his problem-solving approach and thoroughness.” Thank you again Chad!"
shawn s on April 2025
Livermore Mechanical, Inc. is a Union Shop specializing in Residential and Commercial HVAC Service and Installs. We can handle any project or problem, large or small. Over the years, we have built our reputation on communication, honesty, integrity & quality of craftsmanship. We always strive for perfection & we get the job done right the first time. Call today to schedule a consultation!
"Great response time. They were able to replace parts the very next day. Oz was the tech, he was very professional and thorough. Megan was a delight to talk to and assure our needs were met.We highly recommend Livermore Mechanical"
Diane M on January 2021
Livermore Mechanical, Inc. is a Union Shop specializing in Residential and Commercial HVAC Service and Installs. We can handle any project or problem, large or small. Over the years, we have built our reputation on communication, honesty, integrity & quality of craftsmanship. We always strive for perfection & we get the job done right the first time. Call today to schedule a consultation!
"Great response time. They were able to replace parts the very next day. Oz was the tech, he was very professional and thorough. Megan was a delight to talk to and assure our needs were met.We highly recommend Livermore Mechanical"
Diane M on January 2021
Yes, a once-a-year tune-up keeps the system efficient and helps it last longer. During the visit, a technician cleans coils, checks electrical connections, and swaps or cleans the filter. Catching small issues now stops bigger, pricier failures later, so that a quick appointment saves money and stress over the life of the unit.
Changing your AC filter every 30 days is necessary to maintain optimal performance and high indoor air quality. Regular filter replacement prevents dust buildup, ensures efficient airflow, and protects the system from stress that could lead to costly repairs. This disciplined maintenance routine not only boosts energy efficiency but also prolongs the lifespan of your unit by safeguarding its critical components.
An HVAC service plan is worth the cost, especially if you forget to schedule maintenance on your own. A service plan locks in yearly (or twice-yearly) visits, allowing a professional to identify small problems early, clean key components, and maintain energy efficiency. Many plans also include minor repairs or priority scheduling, which can pay for themselves if an unexpected issue pops up.
In a pre-season service visit, your technician gives your system a top-to-bottom check before peak season hits. Expect a filter change, thermostat test, condenser-line flush, electrical-connection check, and coil cleaning. They also tighten loose parts and make minor adjustments so the unit fires up without surprises when temperatures swing. That quick tune-up cuts the risk of mid-season breakdowns and keeps energy use in line.