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TRUSTED BY DIAMOND BAR, CA HOMEOWNERS

  • Average homeowner rating star icon4.7
    Average homeowner rating
  • Verified reviews icon330
    Verified heating and air conditioning services reviews

Find Heating and 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

"In preparation for replacing my HVAC system, I went through a few different estimates. The reason I chose Air-Tech was not because of price, but because I was impressed by the details provided to me. Rod was great. We went into the attic, reviewed all the components inside and out. And we discussed the scope of the work. Once I agreed, he gave me a start date\time. The crew showed up on time and worked hard for two days. Not only was I comfortable with Rod, but the crew was great. My new system is in place and I couldn’t be happier that I chose Air-Tech. If you’re in the market for a new HVAC system, do yourself a favor and call them. You won’t be disappointed."
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+8

44 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for HD MECHANICAL INC
HD MECHANICAL INC
5.0(
26
)

Serving Diamond Bar, CA and surrounding areas

Approved

Super Service Award Winner

In business since 2022

Free estimates

Emergency services offered

"THE OWNER; CHRIS ROBINSON WAS AMAZING, EXCEPTIONAL CUSTOMER SERVICE, GREAT PEOPLE SKILLS. UNBEATABLE PRICING ON UNITS & LABOR I HAD BEEN QUOTED VERY HIGH BY 4 OTHER COMPANIES, HD MECHANICALs PRICING WAS HONESTLY EXTREMELY AFFORDABLE. HIGHLY RECOMMENDED FOR ALL YOUR HVAC NEEDS!!"
Heating & A/C Project
Heating & A/C Project
Heating & A/C Project
Heating & A/C Project
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+14

56 neighbors recently requested a quote
Recommended by76%of homeowners
Avatar for All City Plumbing, Air & Electrical
All City Plumbing, Air & Electrical
4.9(
270
)

Serving Diamond Bar, CA and surrounding areas

Approved

Super Service Award Winner

In business since 2009

Emergency services offered

Warranties offered

The industry's best technicians make the happiest customers. Turn to the pros at All City Plumbing, Air, & Electrical for all of your plumbing, HVAC, and electrical needs. Proudly serving San Bernardino, Riverside, Los Angeles, and Orange Counties. We have over 5000s 5 star reviews across the web from our thrilled customers. Our company goal is to make sure that we have 100% customer satisfaction. We have options and payment plans that can fit in everyones budget. We provide free estimates and you only pay when you're happy. It's no surprise we've received the Angie's List Super Service Award six years in a row! Established in 2009. ACP was created to deliver exceptional service with the highest quality of craftsmanship. We guarantee you will be happy with our services in that we offer a money back guarantee. Our technicians are regarded by their peers to be some of the best in the industry. Our service experts are continuously trained. There isn't a plumbing or hvac problem we can't solve. We have the experience, knowledge and focus to solve any problem you may have. Give us a call today and let us earn your confidence.

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+42

14 neighbors recently requested a quote
Recommended by97%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

"Sam, who came out to give me an estimate for a new system, found out that the old fan motor was the culprit and recommended that we just repair the motor. He explained things in detail, helped us to save money in a genuinely sincere attitude, I was impressed how good his service was, and I recommend him for any HVAC issues. I will be using him in the future."
Response time5 hrs
Recommended by94%of homeowners
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

"George & Earvin came out to diagnose my wall heater and were very helpful from start to finish. Highly recommend you give them a call for any HVAC related needs"
2 ton condenser
2 ton furnace
Response time30 mins
27 neighbors recently requested a quote
Recommended by31%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%
7 neighbors recently requested a quote
Avatar for Penguin Heating and Air Inc
Penguin Heating and Air Inc
5.0(
15
)

Serving Diamond Bar, CA and surrounding areas

Approved

Super Service Award Winner

In business since 2025

Free estimates

Emergency services offered

Penguin Heating and Air Inc is here to help! We offer a variety of HVAC services from service to installations. We are based out of the Placentia, CA area. Give our team a call today. We're looking forward to working with you!\n

Diamond Bar
Diamond Bar
Diamond Bar
Furnace Install
AC Condenser

+6

27 neighbors recently requested a quote
Recommended by6%of homeowners
Avatar for Service Champions, LLC
Service Champions, LLC
4.4(
50
)

Serving Diamond Bar, CA and surrounding areas

Approved

In business since 2000

Free estimates

Warranties offered

"Kayvan was a wonderful service tech! He was on time and professionally checked out the water heater and the HVAC system. He was so polite and friendly. He explained the need for a new filter in the heating unit and showed me photos of the unit located in the attic. He also offered to do a friendly deed for free, which I greatly appreciated, He’s a great asset to Service Champions!"
Area Drain Cleaning
Plumbing
Plumbing
Garbage Disposal
Drain Cleaning

+13

Response time4 hrs
Recommended by79%of homeowners
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Heating and Air Conditioning questions, answered by experts

If your HVAC system's capacity doesn't match the required CFM (Cubic Feet per Minute), imbalances can occur. An undersized system struggles to maintain desired temperatures, leading to discomfort. An oversized system might short-cycle, wasting energy and causing temperature fluctuations. Properly matching capacity to CFM ensures efficient and consistent heating, cooling, and home ventilation system performance.

You should clean your air conditioner at least once per year, but you may need to clean your whole HVAC system (including the air ducts) more often. According to the National Air Duct Cleaners Association, you may need to clean them more frequently depending on factors like whether you smoke, have pets, or have allergies.

Not if you have a standard unit. Because portable AC units actually work to dehumidify the room, you’ll likely need to drain the unit from time to time—but you won’t have to put water into it. There is, however, another type of air conditioner called a swamp cooler that requires water to operate. If you have a swamp cooler, you may need to fill a reservoir with water and potentially ice. But a swamp cooler is different from a standard portable AC unit.

This depends on the extent of the freezing. Some ACs only need an hour or two to thaw out, but others may need a full day to completely unfreeze. Once you turn off the system to let it unfreeze, check it periodically to make sure the drain pan doesn’t overflow. When you turn the system back on, keep an eye on it to ensure it doesn’t start freezing again.

You can buy a new AC capacitor through most big-box home improvement stores, from an HVAC contractor, or from the manufacturer. Use the model number of your air conditioning unit to make sure you purchase the right part for your unit. Also, keep in mind that the cost of this type of part can vary significantly depending on who you purchase it from, so shop around to get the best price.

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

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