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Find Air conditioning pros in Diamond Bar

Avatar for Air-Tech Air Conditioning & Heating Inc
Air-Tech Air Conditioning & Heating Inc
4.5(
202
)

Serving Diamond Bar, CA and surrounding areas

Approved

In business since 1988

Free estimates

Warranties offered

"We needed our 16-year-old HVAC unit replaced, so I narrowed my Angie's List search down to seven Heating & Air Conditioning companies. The ones I chose all had an "A" rating with good reviews. Of those companies, two of them never returned my call, and one didn't work in Los Angeles (it's in Burbank but doesn't work in LA--go figure!). When I called Air-Tech, Heather, the Administrative Assistant, answered the phone--very friendly--and scheduled an appointment. Alex Fish was the Comfort Specialist that came to our home. He was on time, and called me on the road to let me know exactly when he'd arrive. Alex is very knowledgeable; studied every room, looked in the attic where our furnace is located, and examined our condenser and its power supply. Then we sat down and he showed us an illustrated booklet of a house that describes just how an HVAC unit works in a typical home. He walked us through the different systems and gave my wife and me options. He called the office to see if we qualified for an LADWP rebate and a Lennox rebate. We did. None of the other companies we'd seen were this thorough. Before he left, he had written out a detailed proposal including model numbers, what they do, the all-new gas piping, and drain and refrigeration line specifics, etc. Alex was the only person we had seen that wrote a complete proposal before he left the premises. A few days later, I called Alex with additional questions, and he talked to me for 20 minutes answering every question and concern I had. The job took a week to complete, and Carlos and his team covered the work area each day, were very professional and cleaned up at the end of the day, like they had never been there. Many of the technicians have been with Air-Tech for years. To me, that really says something about the company. My wife and I decided to go the permit route. Air-Tech pulled the permits, scheduled the duct testing (we passed), and Heather informed me of what was required with respect to smoke detectors, carbon monoxide detectors and their proximity to any ceiling fans in our house. Because of her heads-up and the outstanding workmanship of the Air-Tech team, final inspection was a breeze. Two techs even came out to double-check everything before the inspector arrived. I can't say enough about Air-Tech. A company that is honest, professional, and does excellent work. For any heating or air conditioning needs, Air-Tech cannot be beat."
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+8

Response time2 hrs
48 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for Trabuco Air
Trabuco Air
4.6(
130
)

Serving Diamond Bar, CA and surrounding areas

Approved

In business since 1996

Free estimates

Emergency services offered

"Short notice call and he made arrangements to come see us with our air condition issue. Very cordial. Mask on as soon as he entered the door and explained everything in detail what he was going to do. Thank you so much! Nice and cold in the house again."
Response time5 hrs
Recommended by94%of homeowners
Avatar for Trinity Heating and AC
Trinity Heating and AC
5.0(
10
)

Serving Diamond Bar, CA and surrounding areas

Approved

Super Service Award Winner

In business since 2021

Free estimates

Emergency services offered

"Chris analyzed my entire AC and heating system and explained in detail the pros and cons of performing additional maintenance. I greatly appreciated his description of future potential issues and his recommendations on how to mitigate them. Thank you Chris."
After: brand new furnace with industrial grade filtration system. Re-wrapped ductwork with fiberglass free wrapping and acoustic soundproof closet/return cavity.
After: 2 Stage Variable Speed Furnace installed perfectly!
After: Properly sized, energy efficient, and installed to code.
Before: Homeowner had tried multiple times to get the pilot light ignited.
Before: Old furnace not installed to code.

+31

3 neighbors recently requested a quote
Recommended by90%of homeowners
Avatar for RS Air Conditioning & Heating
RS Air Conditioning & Heating
4.9(
23
)

Serving Diamond Bar, CA and surrounding areas

Approved

In business since 1990

Free estimates

Emergency services offered

"Ray is very professional, and provided options for my air conditioning unit replacement. Ray went out of his way to replace a small gas line leak that he found. He also drove to Anaheim early on Saturday morning to pick up a part that was needed for the AC unit, and came over to install it so that I would have the air conditioner available for the upcoming heat wave this week. He and his team were on time, and considerate during the installation process. I highly recommend RS Air Conditioning & Heating."
New Outdoor Install
Furnace Install
Satisfied Client
Energy saver!
Carrier Water Soure

+2

Response time3 hrs
Response rate100%
Recommended by100%of homeowners
Avatar for Temp Air System, Inc.
Temp Air System, Inc.
4.8(
54
)

Serving Diamond Bar, CA and surrounding areas

Approved

In business since 2002

Free estimates

Credit card accepted

"We had Temp Air install our AC unit. The best decision we ever made. They were fast, reliable and dependable. Excellent customer service, did a phenomenal job. After a couple of years something was going on with our unit, I called them and immediately they send out a technician Juan, who was phenomenal. He explained what the issue was and resolved it asap! Highly recommend this company!"
Mini Split Installation
Mini Split Installation
Mini Split Installation
Mini Split Installation
Mini Split Installation

+14

Response time10 hrs
Response rate99%
4 neighbors recently requested a quote
Avatar for Easy Air LLC
Easy Air LLC
4.9(
26
)

Serving Diamond Bar, CA and surrounding areas

Approved

In business since 2022

Free estimates

Emergency services offered

"It was my lucky day. Brian was available within 30 min and completed the job at a very reasonable price. The work was performed in a timely and thorough manner. I have spent the 30 days investigating service providers. Brian was one of the few with a CA contractors license with evidence of insured (liability and workers comp) and bonded. And he had no issue with me having a dryer exhaust booster fan. I highly recommend Easy Air."
Cleaned and serviced ac unit.
Cleaned Air return
Cleaned air return
Inspected Furnace
Cleaned out condensation pan.

+4

Response time6 hrs
2 neighbors recently requested a quote
Recommended by65%of homeowners
Avatar for Top Energy Solutions, Inc.
Top Energy Solutions, Inc.
4.9(
62
)

Serving Diamond Bar, CA and surrounding areas

Approved

In business since 2019

Free estimates

Warranties offered

"I highly recommend Top Energy Solutions. During the heat wave my air conditioning system blew out hot air. I expected to wait days for a technician to come out. Leor sent one the next morning. The technician quickly located the problem and fixed it within minutes. Their employees are professional, courteous and very knowledgeable."
Roof Replacement  - Owens Corning Shingle Roof
New Windows Installation in Hollywood
5 Ton Furnace Replacement
Attic insulation
New Mini Split - Daikin Emura

+87

Response time1 day
Response rate98%
7 neighbors recently requested a quote
Avatar for Penguin Heating and Air Inc
Penguin Heating and Air Inc
5.0(
14
)

Serving Diamond Bar, CA and surrounding areas

Approved

Super Service Award Winner

In business since 2025

Free estimates

Emergency services offered

"I highly recommend this company. Penguin heating & Air was very quick to respond to my request, fast text reply, sent them pics, they replied with a quote, which was way lower than anyone else on this site, or even our regular guy that we normally use, we scheduled an appointment for the very next day, which was today, he also finished the job the same day! David did a very good job, very professional. Despite a terrible rainy day, he got the job done. When he was done he walked me through with exactly what he did. He also quoted me for a service on an existing unit and his quote was almost $200 less than what our regular guy charges us... We will absolutely be using this company again."
Diamond Bar
Diamond Bar
Diamond Bar
Furnace Install
AC Condenser

+6

Response time2 hrs
Response rate100%
25 neighbors recently requested a quote
Avatar for SO CAL BOYS HEATING & AIR INC
SO CAL BOYS HEATING & AIR INC
5.0(
54
)

Serving Diamond Bar, CA and surrounding areas

Approved

Super Service Award Winner

In business since 2022

Free estimates

Emergency services offered

"The guys came to the house and proceeded to disconnect the compressor unit. the crane came the whole replacement didn't take more than 30 minutes. We had some problems with the air handler, only because of the space available. But the guys did it and got the replacement in. It took a long time about 10 hours. Over all we were very happy with the service and follow up service. Would recommend them without hesitation."
2 ton condenser
2 ton furnace
Response time2 hrs
Response rate99%
27 neighbors recently requested a quote
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FAQs for air conditioning projects in Diamond Bar, CA

Most professional HVAC technicians require two to three hours to complete an expansion valve replacement. The timeframe depends on your unit's accessibility and whether additional repairs are needed. The process involves recovering refrigerant, removing the old valve, installing the new component, and recharging the system. Scheduling during less busy seasons may result in more convenient appointment times.

Operating your air conditioner with a malfunctioning expansion valve isn't advisable. Continuing to run the system could potentially damage other components, particularly your compressor, which is significantly more expensive to replace. If you notice performance issues like inconsistent cooling or unusual noises, it's best to have your system inspected before continuing regular use.

Expansion valves don't have a standard replacement schedule, as their longevity depends on system usage, maintenance frequency, and environmental factors. Regular professional maintenance helps identify potential valve issues before they cause system failure. Having your HVAC system serviced annually allows technicians to monitor component condition and recommend preventative replacements when necessary.

Refrigerant leaks require prompt professional attention. If your expansion valve is leaking, you'll likely notice reduced cooling performance and possibly hear hissing sounds near the unit. Addressing leaks quickly prevents further system inefficiency and avoids the environmental impact of released refrigerant. Your HVAC technician will need to repair the leak and recharge the system with the proper refrigerant type and amount.

Because many AC issues present similar symptoms, professional diagnosis is recommended. Problems like inadequate cooling, inconsistent temperatures, or strange noises could indicate expansion valve issues, but might also stem from refrigerant leaks, electrical problems, or airflow restrictions. A qualified HVAC technician has the tools and expertise to accurately identify the root cause and recommend appropriate repairs.

The Diamond Bar, CA homeowners’ guide to air conditioning services

From average costs to expert advice, get all the answers you need to get your job done.