
Serving Diablo, CA and surrounding areas
Approved
In business since 2005
Free estimates
Emergency services offered
"We like them, they are very good. They are going to do our air conditioning."





Serving Diablo, CA and surrounding areas
Approved
In business since 2005
Free estimates
Emergency services offered
"We like them, they are very good. They are going to do our air conditioning."




Serving Diablo, CA and surrounding areas
Approved
Super Service Award Winner
In business since 2021
Free estimates
Emergency services offered
"Fast and available when i needed them in a pinch. Sam did and amazing job! He listed out my options and walked me through each solution to get my air conditioning in working order ago. Would use this company again"





+27

Serving Diablo, CA and surrounding areas
Approved
In business since 2009
Free estimates
Emergency services offered
"To start, I put in for an emergency call to Freschi and was told they would call me 30 minutes before. They never called me back. Freschi sucks!!!I I also put in a request on HomeAdvisor on Thursday night and was given Global Warming Heating and Air as one of their verified contractors. I got a call at 7am from Rudy. I called back around 830am and we made an appointment for 1130am. He showed up at 1105am and quickly diagnosed the problem. He recommended replacing the furnace(which houses the blower assembly) due to the cost of repairs and its 17 year old condition. He didn t try to up sell me for an entire new system. He said my AC is working well so there s no need to replace it. I decided to replace the furnace and he said he d be back around 130pm. Rudy and his crew were back by 1pm. From the start of demo to it running again was less than 2 hours. Rudy s customer service is top notch!! From now on, I will only be calling Global Warming Heating and Air. I can t say enough good things about Rudy s business ethics and timeliness. A+++++"





+9

Serving Diablo, CA and surrounding areas
Approved
Super Service Award Winner
In business since 1991
Free estimates
Emergency services offered
"Great team. While the job is messy as they have to work under your house. Aire Serv was great to work with. We needed new ducts and boots and my house is now moving air better than it has in twenty years. Highly recommend Aire Serv."





+58

Serving Diablo, CA and surrounding areas
Approved
Super Service Award Winner
In business since 2016
Free estimates
Emergency services offered
"I bought my heating and air conditioning systems through Perfect Star, and use them for a heating, and an air conditioning tune up each year. They work is exceptional, as are the employees. I have recommended perfect star to friends, who all were more than satisfied."





+8

Serving Diablo, CA and surrounding areas
Approved
Super Service Award Winner
In business since 2008
Free estimates
Emergency services offered
"Exceptional company, exceptional work done for us. We had an emergency need with a failing furnace. 411 was able to come out on Sunday, the same day. Our HVAC system was 35 years old and I knew it needed to be replaced, and they were able to do so within two days. In addition, they were able to identify why our upstairs remained hot in the summer despite air conditioning. They were able to install a withdrawal vent that will greatly increase the removal of hot air in the summer, and therefore the effectiveness of our air conditioning. All this was done at a very competitive price. I feel very lucky that they answered our call that day. I can?t recommend the more highly."





+3

Serving Diablo, CA and surrounding areas
Approved (Corporate)
In business since 1981
Free estimates
Warranties offered
"The crew from Albert Nahman did a great job from start to finish. The project was to replace the original ductwork in our 60 year old house. Tom provided excellent advice for the estimate then Bryan’s crew did the job, 2 days, within a week of my acceptance of the proposal. Great work."





+73
Serving Diablo, CA and surrounding areas
Approved
In business since 1978
Free estimates
Warranties offered
"I found Jim's Air Systems through HomeAdvisor, and Josh was the first contractor to reach out to me personally, not through an automated service. From the start, communication with him was excellent. I provided him with a detailed description of the job, along with model numbers and photos of my existing system. He reviewed everything carefully rather than giving me a quick, generic quote. I received another bid for comparison, but the other contractor was significantly more expensive and wanted to upsell me. It was refreshing that Josh understood I had done my research, knew what I wanted, and didn't pressure me into unnecessary upgrades. Josh's team arrived on time, completed the work as scheduled, obtained the required permit, and left my home as clean as they found it. Overall, a great experience and a solid value. I wouldn't hesitate to recommend them."

Serving Diablo, CA and surrounding areas
Approved
In business since 2019
Free estimates
Emergency services offered
"The contractor was friendly, found the issue to my HVAC heating system, repaired and provided alternative solutions should I need to replace the system due to its age."





+4

Serving Diablo, CA and surrounding areas
Approved
In business since 2003
Free estimates
Credit card accepted
"My AC stopped working last November, and since then i had 4 contractors i called to fix it, i was turned down by everyone. i called Tyndall and peter came out and talked about it with me, actually troubleshot it, and 2 days later had parts and fixed it. i would give them 6 stars if i could. im so glad to have my ac running again. my recommendation, if you want something done, call Tyndall, because the rest of the contractors seem to just say its not fixable and leave without even looking at it. these guys were the first people that listened, then looked at the unit before declining service, and then actually fixed it. 10/10 great job and thank you."
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.
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