Bob is the best and most knowledgeable person I have ever seen. He truly cares about customers besides he is very nice and thoughtful. He fixed the problem that previous several persons could not fix. I highly recommend him to anyone who needs to get the job done in a professional way. read more

We're sitting inside cool and comfortable on a hot June day, thanks to the incredible team at Diamond who replaced our old broken 5-ton AC with a smaller, more energy efficient modern Mitsubishi heat pump system. A huge thanks to Anthony and Tiffany for coordinating all the logistics, Anthony in particular was so helpful from start to finish, always available, responded immediately to any question, and just made the whole process incredibly easy. An especially big thanks to our installer Bobby and his crew who did such an exceptional job carefully removing the old system and doing a beautiful install of the new one. They also completely reworked the AC closet, moving the system forward and sealing everything off cleanly, what was once a poorly converted linen closet now has potential for usable space behind it. Whereas the old system sounded like a jet engine taking off, the new Mitsubishi is astonishingly quiet, the condenser is outside our bedroom and you hear literally nothing. It works flawlessly and has been keeping the house perfectly cool through what's shaping up to be a hot summer. This was not an easy install either. The house, like many older homes, is full of quirks and Diamond did an amazing job working around all the pitfalls that come with squeezing a central HVAC system into a house not originally designed for one. Everyone at Diamond was a total pleasure to work with and have in our home. Their pricing was fair and reasonable and the quality of their workmanship is just excellent. If you need any kind of HVAC work done I highly recommend reaching out to Anthony and the Diamond team. Thanks so much guys! read more

Great experience! Mike and Hau were professional, knowledgeable, and trustworthy. They explained everything clearly, answered all of my questions, and made sure the job was done right. They were able to fix a problem where a different HVAC company told me a new AC unit was needed. The quality of their work was excellent, and the pricing was fair. I really appreciate the great service and would definitely recommend Diamond Air Services to anyone needing HVAC work. read more

Great service and pricing! Purchased a new AC/Heater package unit for my Tri-level condo. Anthony and his crew took care of everything, including the crane service to hoist it up to the roof. Installation went great, and the unit is working beautifully! Highly recommend Diamond Air! read more

I selected this company based on the reviews and it worked. The customer service in the main office was awesome, but even more important, Howie, the gentleman who came to service our HVAC system was phenomenal. He was highly communicative and competent. Our problem was solved, and we are grateful. read more

They have done our annual maintenance for a few years. We needed a repair this past week Howie did an excellent job!

Anthony was great to work with. He responded quickly to our request for a complete HVAC system replacement and got the job done within three days. My wife was pregnant at the time and really needed cool air, so we greatly appreciated how he prioritized our request. Thanks to his prompt service, our home was comfortable again in no time. The new system works great and provides excellent value for the price. Highly recommended -- 10/10! read more

7/30/26 Anthony is very professional, courteous, friendly and honest. His company installed a 3 ton Carrier AC and his crew endured 130 degree heat installing a new furnace and ducting in the attic which my wife and I appreciated. He also took care pulling all the permits and dealing with the inspectors. He gave us the best pricing compared to several other contractors. Can highly recommend for your ac and heating projects. Dave K read more

We had a 5-ton, 3-phase Carrier package unit installed on our commercial rooftop, and the entire process was fast, smooth and reliable from start to finish. Their team handled the install with real expertise, and everything was up and running couple hours later exactly as promised. We later asked if they could adjust the blower speed to push more air, and they came out quickly a day later without any hassle. That level of responsiveness is hard to find. Highly recommend Diamond Air Services for anyone looking for qualified HVAC work. read more

We are very pleased with Diamond Air Services. They were able to give us an appointment within days, which was great considering we were in the middle of a very hot couple of weeks. Sal, our technician, actually was able to arrive earlier than scheduled time, which worked out well. He was able to determine that our air conditioner needed refrigerant, but did a thorough inspection to make sure everything was in good working condition. He was efficient and knowledgeable. We have already recommended Diamond Air to a neighbor the same afternoon our work was completed. read more

Anthony was very thorough explaining all the differences of HVAC systems and he is very personable. The price is fair. The installation went smoothly. Victor and his crew came and busted it out. They answered all of our questions. read more

I had an issue with my heater at my office. I checked around for local companies and Diamond Air was located at the same business park . I drove over and was able to schedule an appointment same day. They came out and diagnosed the issue, repaired, and serviced my system. I got my heater back up and running. Thank you for the quick response! read more

Diamond Air Services - Heating & Air Conditioning/HVAC Near Me - Irwindale, California

Our family would like to thank Diamond Air Services for their excellent customer service. Howie and Baren (please excuse us if we misspelled your name) arrived on time for their scheduled consultation and clearly explained the issues and next steps. Our heater had suddenly stopped working earlier this week, and they were prompt and efficient with the repair. We especially appreciated their clear communication throughout the process and their attention to detail--before entering our home, they even wore booties while checking our thermostat. We had a very positive experience with Diamond Air Services and would highly recommend their services. read more

I had Diamond air services install a new Lennox heat pump and furnace. The installation went smoothly. The crew was on time, efficient and knowledgeable. Permits were obtained and the city of Monrovia confirmed everything was installed to code. The price on the project was better than 4 out of my 5 estimates. Howie Vu oversaw the project and was great to work with. The new system is a huge improvement. Highly recommended!!! read more

Howie and his team did an excellent job installing our new heater and removing the old one. From consultation to installation to city inspection, everything was completed so quickly and efficiently. The entire process was smooth from start to finish. The price was very reasonable, and the service and communication were clear and easy throughout. They were professional, clean, and respectful of our home, making sure everything was tidy when the job was done. We also appreciated the helpful recommendations they provided. Highly recommend Howie and his team! read more

I needed a routine checkup on my HVAC system and Diamond Services did an excellent job! Communication was clear and it was super easy to schedule an appointment. Mike was very well informed too and did a good job at inspecting and making sure everything was functioning properly. Pricing was fair and the whole thing took less than an hour. If I ever need another inspection, I know who I'm reaching out to again! read more

Yesterday I had them come to maintain my air conditioning unit. They are very upfront, honest and showed me pictures of everything in the attic, AC units, furnace, electrical wires. He was ontime and very respectful and quickly changed my air filters and washed my AC units. I loved this because I've had other places come to my other business units and upcharge me and try to get additional services into the thousands I appreciate them and will continue to use them in the future. read more

I had a problem with my AC. It wasn't working so we called diamond air. Very fast service. They arrived the same day. Very organized. They came when they said they would. Communication was great -took pictures and explained problems. No upsell. Great price. Technicians were nice. Tested my ac to make sure it worked. Overall, great customer service. read more

Their people are great! Jose and Oscar D. were very nice, patient, and informative. They explained everything they did and were doing thoroughly. Their work also looks very nice. I have to thank Anthony. He came to look at my furnace and gave me a really good price. Anthony managed the whole project very well. read more

I had a problem with my air conditioner and I needed someone soon because it's getting cold. The lady Tiffany was very professional and was able to get me on schedule and they came out and they found the issue right away. Great customer service. read more

Recently, I discovered that my 20yr old central air conditioning system needed replacing. I created a checklist of the specifications I was looking for, including the make and size of different HVAC products, city permit costs, installation timelines, and anything else that might affect the project. I then checked Yelp and chose 4 five-star rated local HVAC companies and requested a estimate from each. Diamond Air Services had the most reasonable price and was the clear winner. Anthony (owner of Diamond Air) examined my existing system and provided the estimate. He arrived exactly at the agreed time, outlined possible options, but never tried to up-sell. After the meeting, he emailed a comprehensive bid with firm prices for each option. His price included city permits and after-installation testing. I signed the agreement, and within one week, Diamond Air installers completed the installation, the unit was tested and passed inspection by the city. This experience was one of the most professional and trouble-free construction projects I've had. I heartily recommend Diamond Air to anyone in the market for an HVAC system. read more

Pretty good overall experience. The quality is solid, the service is great, and the pricing is even better. I did my research and compared at least three different companies. Some of them felt very sales-driven, but Diamond Air stood out as more professional. Whenever I asked about things like air scrubbers or humidifiers for the HVAC system, they were always able to give clear and knowledgeable advice. Unlike some companies that don't even understand what you're asking and just try to push a sale. read more

Good service and attitude.The technician explained clearly and precisely what I needed .Good job Anthony and thank you again

The guys were great. I needed a new furnace and they were professional and did a great job. The new unit works perfectly. I would highly recommend them. read more

Two years ago we were in the market for a replacement HVAC system and decided to install a heat pump instead of a gas furnace. We chose Diamond Air and a Carrier Infinity system for reasons of competence, cost, and the best product fit. The installation was a pleasant, multi-day experience and we've been delighted with the system. Now 2 plus years on Jose from Diamond Air came to do an annual service on the system. He was friendly, courteous, and went over the system top to bottom, giving it a clean bill of health. read more

Great service and excellent communication. Competitive pricing for HVAC systems. Highly recommend this company.

Contracted Diamond Air Services to do the annual service for my mom's and our home and was extremely happy with the work performed by their very professional technicians. I would gladly hire them again as they gave me a good discount for including both homes! Thanks! read more

My Tech Jose, was very knowledgeable, friendly, helpful and also very professional and right on time.

My family and I couldn't be happier with the work that Diamond Air has provided us twice now. We requested their service when we turned our garage into an office two years and needed a mini split installed. Howie was professional, worked quickly, yet thoroughly, and had wonderful customer service! We were so happy with the service that when the AC in our house went out, we called right away. Howie was courteous and solved the problem quickly, and for an amazing price. We genuinely couldn't be happier! read more

The team at Diamond Air is responsive, reliable and professional. They helped us replace an AC unit right before the summer heat came. They were always willing to hear our feedback and requests throughout the process. They made sure the work wasn't done until we were satisfied with the end result. Thanks to Tiffany, Jose, and Mike for all their help! We're loyal customers because of them! read more

I'm so glad I called Diamond Air Service for a new HVAC unit! I've been stressing for months going thru home warranty with others HVAC companies that kept going in circles with me. D.A.S gave me the full scoop of my situation that I needed a new HVAC unit. I was so fed up with the old unit kept shaking the whole house every time we turned on the AC. It would make a really loud noise and the walls would shake. Definitely a new unit was needed. It's been almost a year now with the new HVAC unit and no issue since the old one. The installation went smoothly, AC runs quietly and it saves more on our electric bill too! If you have any issue with ur HVAC just call Diamond Air Service for your need to cut all the stress out. It's so worth it at the end and even better with great service! Thanks again!! read more

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We are so impressed with Diamond Air Services! We found them on Yelp and we were impressed by the great reviews. I had called several companies to get quotes for cleaning our heat system and ducts. Their quote was reasonable and we were impressed when they told us the methods they use and that their equipment has hepa filters. Baron and Christian did a great job and they were great to work with. They kept us informed about the process and they accommodated our needs, and they did all of this professionally and with courtesy. Right after they left, I turned on the heat and realized that one of the registers was blowing shut. Fortunately, Baran and Christian hadn't driven away yet and they kindly returned and fixed it so it would stay open. We also met with Mike to discuss the prospect of adding A/C. We're impressed by his thoroughness and problem solving skills. We're grateful we found Diamond Air and look forward to working with them in the future. read more

It's time for my AC to be serviced and I was not happy with my last service man. Then I found Diamond Air. Diamond Air is very easy and pleasant to work with at the same time professional. They confirmed the appointment with a text message, and on the day the service person Mac confirmed his coming and the company confirmed that Mac is the one coming again. These all have given me peace of mind knowing exactly when and who. Mac was great doing all the maintenances and cleaning, and super friendly. Plus, the price is very reasonable. Highly recommend! read more

We had Diamond Air Services installed a new heat pump A/C for us. They are terrific. The technicians Barajas and Christian did a great job, they are awesome. read more

Our dryer hasn't been working properly for the past 3 1/2 weeks but there was nothing wrong to be found with it. As it turned out, it was the air vent of the house that needed clearing and cleaning. Enters Ashton and Anthony to save the day and a whole lot of time as well. We've been hanging clothes out to dry on a line which works fine but takes a while. I called on Tuesday to explain the issues we were having and they confirmed they could fix it. They arrived just before 9am on Wednesday and by 9:30am the problem was fixed. They came prepared, were efficient, friendly and polite. We would absolutely recommend Diamond Air based on our experience today. read more

Definitely recommend Diamond Air Services to everyone. Oscar was excellent! Came in on time, cleaning the AC unit, install the new thermostat. Everything works perfectly. Glad I use their services and will definitely call them back ifor future maintenance and other HVAC issues. read more

I've been using Diamond Air Services for about ten years. They consistently provide excellent services at competitive prices. This is the third air conditioner system they've installed for three different houses--my brother's, my old one, and the new one--and they're still working well. I highly recommend them to anyone in need of air conditioner services or a new system. I've always worked with Howie, who is professional and responsive. Thanks Howie. read more

We had Diamond Air service our air conditioner in preparation for the summer heat. Mike was on time and so easy to work with. He explained what and how he was going to do it. Gave us a thorough assessment of our HVAC readiness, cleaned the whole unit and checked out all the duct air flow adequacy. We are extremely happy with Diamond Air Services. Quality and professional service is hard to find and at very reasonable rates! Thank you Mike! read more

Complete professional, and super nice staff. Tiffany that does the booking and asks questions about your needs. Was extremely knowledgeable and answered all my questions and addressed my concerns. The 2 technicians who came to my home to service the HVAC were extremely excellent at their job and very people friendly. Will inspected everything first and informed me on every aspect of what they were going to do. Carl who cleaned the ducts took time to make sure everything was done correctly. We also had our dryer vent looked at. Ashton went over and above making sure the area behind our stackable washer/dry was cleaned. He also had wonderful people skills and was a great communicator. In my opinion this company is at the top of their game with the work. The technicians really mad me know that they listened and did their work accordingly. Will definitely have them do yearly maintenance on our HVAC system from now on! Thank you Will, Carl, Astin, and Diamond Air for your service!! read more

I needed to have my HVAC serviced and also do some long overdue cleaning. Will and Dylan came next and did everything! Both very professional and work done was excellent. Would strongly recommend Diamond Air for future needs. read more