I wish I could give more than 5 stars for CES and technician Patrick. I called them for a heater and thermostat problem, and Patrick quickly figured out what was wrong and explained everything clearly so I knew exactly what he was doing. He was professional, respectful of my home, and very detail‑oriented, double‑checking his work as he went. What really impressed me was his dedication: he stayed working late into the night to make sure the heat was fully restored and the thermostat was working perfectly before he left. It's rare to see that level of care and commitment these days. I highly recommend CES, and I will definitely be asking for Patrick by name next time I need service. read more

CES Tech scammed me into paying for a return vent upgrade that did absolutely nothing to fix my problem. I originally contacted CES Tech through my Choice Home Warranty because my utility bills were unusually high in both summer and winter. After inspecting my HVAC system, they told me my home's return air capacity was insufficient and strongly recommended adding an additional return vent. I repeatedly asked whether this would actually solve my problem and reduce my energy bills. Based on their assurances, I paid $1,200 for the upgrade. Now, after waiting 8-9 months, my utility bills have not gone down at all. Worse, I later found out that my AC wasn't even operating at full capacity because of a Puron (R-410A) refrigerant leak--the actual issue, which CES Tech completely failed to identify during their inspection. Instead of diagnosing the real problem, they sold me an expensive upgrade that provided no benefit. Based on my experience, I would strongly recommend getting a second opinion before agreeing to any costly HVAC upgrades from CES Tech. read more

I have different ratings on different things. overall 3.0 - context - CHW hired this company for a HVAC a/c refrigerant leak in feb 2026 - communications - 2.5* - - [[HIGHLIGHT]]they dont usually pickup office phone.[[ENDHIGHLIGHT]] - [[HIGHLIGHT]]i had to ask 3 times to share the work order copy.[[ENDHIGHLIGHT]] - it took them more than 3 weeks to fix from start to finish - professionals who fixed the issue - 3.5* - very courteous - after job done, they did not show me both cooling and heating works, but only cooling - they did not say anything about follow up if things do not work next week read more

I would highly not Recommend to go with this company. This deserves no star. [[HIGHLIGHT]]It's a fraud company and they do not answer phone calls or respond their emails.[[ENDHIGHLIGHT]] CES installed heater for us in the week of Christmas. They charged us $3645. 2 weeks after installing new device, the device stopped working. We have been trying to call them to send a technician and they are not even responding. Even after paying them they have been so irresponsible with their customers. [[HIGHLIGHT]]We have kids at home and it's 40 degrees F and we are without a heater as they are responsive to calls and emails[[ENDHIGHLIGHT]]. read more

Stay away. [[HIGHLIGHT]]They do not care to communicate about the progress of the work they have signed up for.[[ENDHIGHLIGHT]] [[HIGHLIGHT]]You cannot get to them through any of the modern channels like email, phone or SMS.[[ENDHIGHLIGHT]] read more

Our home warranty assigned CES-TECH for fixing our furnace. We were so concerned that the furnace would not be repaired before Christmas when the weather was so cold. [[HIGHLIGHT]]CES called me within 48 hours and scheduled an appointment for the next business day.[[ENDHIGHLIGHT]] The technician, Patrick came and determined the motherboard failed and needed to replace. Patrick came back a week later after a new motherboard was ordered and received. He replaced the motherboard, tested and the furnace worked like a magic. I highly recommend Patrick. He is very thorough and professional. He is also so understandable that he even asked if he should take off his shoes. Thank you so much, Patrick' read more

*** Believe the bad reviews*** -- they are 100% accurate. CES-TECH Heating and Cooling is one of the most unprofessional companies I've ever dealt with. [[HIGHLIGHT]]They were assigned to me by AHS and were supposed to call to schedule an appointment. They never did. I had to reach out to them myself, and the earliest slot they offered was two days later, within a 3-hour time window. I had no choice but to accept it.[[ENDHIGHLIGHT]] [[HIGHLIGHT]]On the day of the appointment, no one showed up during the window. No call. No text. No email. I had to call their office, and the front desk told me someone would be there "soon." Meanwhile, when I logged into AHS, I saw they had silently changed the appointment window without informing me.[[ENDHIGHLIGHT]] I had already adjusted my schedule based on their original time -- only to find they shifted it without a word. [[HIGHLIGHT]]Even after the new window passed, no one showed up. I was left waiting for hours.[[ENDHIGHLIGHT]] After this frustrating experience, I checked their Yelp reviews and found I wasn't alone. [[HIGHLIGHT]]So many people have reported the same issues -- no-shows, poor communication, rescheduling without notice.[[ENDHIGHLIGHT]] I wish I had seen those reviews earlier. Please believe the negative reviews. This company is unreliable, disorganized, and completely disrespectful of your time. Avoid them if you can. **** Update #1: Eventually, a technician did show up. After inspecting the system, he said a part needed to be replaced. He told me he would order it and come back on Wednesday to install it. On Wednesday -- after multiple follow-ups -- he finally returned. And then... dang. He admitted he brought the wrong part. According to him, there was a miscommunication or misunderstanding with the part number. He said he had now ordered the correct part and confirmed it would arrive by Friday, and he'd come back to fix it. **** Update #2: [[HIGHLIGHT]]And now it's Friday. No calls. No technician. No communication.[[ENDHIGHLIGHT]] Honestly, at this point, I wasn't even surprised -- just exhausted. So again, I had to call them. [[HIGHLIGHT]]The front desk sounded completely unaware, saying, "Oh, do we have an appointment today? Let me check."[[ENDHIGHLIGHT]] Seriously? A minute later she told me, "The technician is out sick, so we'll have to push it to Monday." I asked if they could send someone else -- the answer? No, because apparently no one else knows what the correct part number is, and the technician isn't picking up his phone. That's how poorly they run things -- one guy is out sick, and the whole operation falls apart. [[HIGHLIGHT]]I had taken the day off work -- unpaid -- just to be available for them. Now I'll have to take another day off on Monday, again unpaid.[[ENDHIGHLIGHT]] And who knows if they'll even show up then? [[HIGHLIGHT]]This experience has been beyond frustrating. I feel disrespected, ignored, and totally taken for granted as a customer.[[ENDHIGHLIGHT]] It's not just bad service -- it's a complete lack of basic professionalism. I wouldn't wish this kind of experience on anyone. read more

CES was assigned to me by AHS to look at my furnace as my heater stopped working. [[HIGHLIGHT]]I received a call on the same day I open the request, 2/12/26, through AHS to set up the appt the following Monday, 2/16 with a window from 9-12.[[ENDHIGHLIGHT]] Patrick arrived at around 9:45. He was courteous to ask me if he should remove his shoes before entering the house, which I truly appreciate. He needed to replace a part (I forgot the name :-)) that thank goodness he had in his truck. It was replaced and he waited to make sure the heater was turning on and working. He was done in about 35 mins from arrival time. Patrick was very polite. read more

AHS service call for my furnace that wouldn't stay on. Patrick came to diagnose the issue, ordered the necessary parts, and promptly came back to do the repair. The inducer was replaced and the furnace works flawlessly now. This is the best company I've worked with through AHS. read more

Company was assigned by my mom's home warranty. They took weeks to supposably fix her ac but never did was sent back took more money installed a new system. Guess what broke that my parents are still without AC. Hot as ever older people with health issues. Ceaser the owner has no sense of time just like his employees they give you a window but show up when they want if at all. Next call better business bureau. read more

[[HIGHLIGHT]]Juan came right on time.[[ENDHIGHLIGHT]] Diagnosed the problem and fixed it quickly with great advice concerning maintaining the central AC to keep it working. Great guy from a great company. Thanks. read more

Service Tech Patrick was amazing, knowledgeable and explained actually what the repairs were on the AC Unit. Would highly recommend this company for any of your service needs! read more

CES Tech was assigned by AHS home warranty service. They took more than one month with multiple visits by multiple technicians to fix the issue. They are not technically competenet especially with latest modern heat pump systems. To make matters worse, they broke my attic door, which they refused to repair. read more

The young man came today 11/4/24, for a heater tune up through AHS. He was on time, changed my filters and made the necessary checks to make sure I was ready for the winter months. read more

We were assigned them through American home shield and the tech was prompt on the first visit, diagnosed the problem and said he would come back on a weekend since my wife and I both work multiple jobs during the week, [[HIGHLIGHT]]he no called no show the first scheduled Saturday wasting our day off[[ENDHIGHLIGHT]] and rescheduled for today between 7am and 11am [[HIGHLIGHT]]it's now 10am and still no word from them , what horrible customer service![[ENDHIGHLIGHT]] read more

Amazing, professional service. They arrived at the agreed-upon time and quickly fixed my AC in a heat wave. I'd highly recommend this company for your HVAC needs. read more

Had a terrible experience getting my HVAC fixed. [[HIGHLIGHT]]Have to call them continuously for half an hour before they answer their phone - they don't have voicemail setup.[[ENDHIGHLIGHT]] The technician refused to take his shoes off or wear booties and did not even put the HVAC air filter back after. read more

[[HIGHLIGHT]]I was able to get an appointment the next day and Cesar came on time.[[ENDHIGHLIGHT]] I told him the problem of my AC/heat and he knew right away what was the problem. He replaced the broken capacitor and bam! My AC turned on. He said it's a common problem. Nice and quick! I was very happy and satisfied. read more

Pathetic service - They were assigned to me via my home warranty (AHS) and I've called the publicly listed number (925) 339-5537 like 50 times. Nobody ever picks up the call. Avoid them! read more

I'm a pissed off Customer. [[HIGHLIGHT]]We have Home Warranty and this Co was assigned to us. I got an appointment next day[[ENDHIGHLIGHT]]. Technitian came out, said it's the fuse, I'll place an order for it ( he didn't have the right one to fix on the spot ). next day another Tech came out. replaced the part and NOTHING! He spent another 30-45 minutes and figured out some other issue. He said he will come bk next day to fit it. Same Tech came back on the 3rd day and finally fixed the A/C. says we are covered for 90 days parts/labor. 30 days later without once turning on AC as it's been cold in Hayward we noticed that Thermostat is unresponsive. called Home Warranty and they say I have to pay again for the service or call the CES-Tech and see if they come look at the unit as it seems the exact problem is bk. called CES-TECH and sure enough, they refuse to back their 90 days later without warranty and I have to go through the Home Warranty and pay the copay again for someone to come out and fix the issue! [[HIGHLIGHT]]Terrible Customer Service!!!!![[ENDHIGHLIGHT]] took three trips to fix the issue and then it seems the unit was maybe not fixed???!!!!! read more

Worst customer service ever. Cant trust this company at all. Been waiting about 2 weeks for ac repair and nothing yet. Go get your money worth on another PROFESSIONAL company. ANY other company than ces-tech (garbage). Youll help yourself out of a headach and the heat. read more

My furnace was acting funny. They fixed it but it did not last and the same problem happened again. When they came back, they did the correct adjustment to a sensor. They should have made this adjustment when they installed the part the first time. read more

Techs were not well trained. Inexperienced. Did NOT COMPLETE THE JOB before leaving. I called company owner to discuss the situation. He was rude, dismissive ans could CARE LESS about my priblem.. I spoke I w with the Home Warranty company who looked into the problem. They acknowledged the VERY BAD ATTITUDE of the isner. They transferred my repair to another service company. I will NEVER DEAL WITH THESE JERKS AHSIN. I recommend that you stay far away. read more

They never answer calls! Scheduling was a nightmare. When the technician finally showed up, he stated he fixed it (left in less than 15 mins), its been 3 hours and it still has not cooled even 1 degree. Tried calling many times to get a hold of someone - no answer, no voicemail setup. read more

been waiting two weeks at the hottest days of summer for them to make a appointment with me two weeks after they "ordered my part". didn't even show up to the appointment that they made and had me sit there and wait with no call back the day of appointment, id be embarrassed as a company seems like they do it a lot read more

They installed our a/c in Sept it's now January and repairs still haven't been completed Won't pass inspection. Without repairs

Juan, the Repair Tech, was very professional and quickly diagnosed the problem with my A/C unit and quickly repaired the unit. Running now and cooling down the house, (thank goodness). Been tough sleeping the last couple of nights. Very friendly and personable young man. Great Job !! read more

This company is the worst experience. After a long month of them, sending 2 different techs out (1 including Caesar) and no changes to the AC, and trying to fix it at 9:30pm when the window slot was 2pm to 5pm, and myself taking off days of work without any solutions, no communication, and lack of overall customer service, I will be working with another company. If you have a toddler and it's summer time and your HVAC stopped working, do not use this company. They will waste your time and money. read more

Before writing my review, I thought all the bad things happening to my AC/Heating system like, (repeated breakdowns, repeated scheduling, waiting all day for Cesar then doesn't show up, or leaving messages and no answer back; and the only way to talk to him is wait a few days, and call Cesar with another phone), was just happening to me. Until I read all the negativity coming from Cesar Ramirez (Ces-Tech Heating and Cooling). My system was replaced by Ces-Tech back in June 2021. A few weeks after my system was installed, Cesar had to come back to check why it's not cooling when it's a new system. No problem there. On Dec 2021 Cesar had to come out again because now I'm not getting any heat this time. Cesar sent a couple a guys claimed they fixed the problem. It wasn't that long I called back because of the same issue. In which Cesar spoke to my husband over the phone and walked him through to check a few things. Summer of 2022 came our AC was acting up again. This is when the repeated rescheduling, waiting for a call back from Cesar, not keeping the window hours appointment, waiting all day then not even showing up started happening. When Cesar was finally ready on his own convenient, he came to see the problem. He claims there was leak and filled it. When winter 2022 came, it was happening again. Instead of going through what I just went through during summer. We decided to just layered up and cope with the cold. It is now May 2023. It's starting to warm up again. Not like winter you can bundle up to be warm. It's hard to sleep when it's too hot. We turned on the AC, it worked for a few days, after that it went back to the same problem no cold air coming out. This time I reached to a few HVAC company because I did not want to waist Ces-Tech (Cesar Ramirez) time as well as mine. Unfortunately since my AC is less than 2 years old, it would still be under warranty, so the 2 companies I called said they couldn't help me. Excepted one company who came and determine the issue but suggest to call the people who sold the system because my system still has an 8 year warranty. So fortunate enough Cesar answers the first call. I got the appointment the following week. The appointment window was between 10a to 1p but unfortunately waited all day to his convenience to show up. Cesar's finds was the same thing, claims there was a leak and filled it. Hopefully and praying this is it. Winter and Summer is just getting old for the same mishap to keep happening and I have another 8 years till the system warranty will expire; I've only used 2 "OH NO!!!". I'm sure Cesar is as tired coming to my house as I am tired to keep calling him. I hope it ends this summer with all the complication because I'm exhausted and frustrated. SooooYessss I kind of chucked when I read the other reviews that it was also happening to them. I wasn't being singled out. read more

Overall a pretty good experience considered the backlog and clients need to have their AC addressed in this scorching weather we are having this week. The technician came 3 hours late but did diagnose the real issue which was a leak at the controller furnace level and he addressed it and replenished fully the freon. The technician was friendly and courteous enough and explained what's happening. read more

Home warranty company sent us to them. Technician came to our house 5 times and each time left saying the furnace was fixed. It would then work for 15 minutes and then stop working. Finally said that it was due to a bad installation and a part needed to be replaced. Fine but couldn't you have told us that the first time instead of "fixing" it and then leaving five times!? Then he was supposed to file a recommendation with the home warranty company that we used and never did it. I'm on hold with the warranty company for the god knows how many-th time. It's been over 2 months since we first filed the work order, and I have no idea when the furnace will be fixed. read more

HORRIBLE business practices all around. Their service and communication is all off. The company makes false promises and fails to show up for appointments or even communicate that they aren't showing up . Office staff also doesn't provide proper information . If you want to deal with unprofessional people, choose them. If not, save yourself the headache read more

ETA nothing "Cesar" says below is true. He claims I had bad experiences with other contractors, but that's not true. Everyone else who has been here was wonderful, helpful, professional, and effective. There was no screaming. I have the whole interaction on video since he lies. The icing over fix-technique he told me about did not fix the machine, and the technician who did, easily, for less than $200 in less than 30 minutes that very next morning, said his fix, attitude, and demeanor were all laughable. I would give zero stars if it was possible. This company, and specifically "Cesar R." are horrendous, as others have mentioned. By the way, Cesar has refused to give me his name, so I'm not sure that's who he is... just inferring from yelp here. Like others, I only used Cesar due to a home warranty requirement. Despite my conversation with Cesar last August I *very reluctantly* allowed him to fix two aspects of my air conditioner. He knew the issue was temporary and said he would guarantee his work for one year. This is the only reason I agreed to have him replace anything at that time. That was 8/4/2021. Today, 6/2/2022, I called CES-TECH because my air conditioning is no longer working. After being placed on lengthy holds twice, I was told "your technician" (who is Cesar... the owner) would not honor the documented warranty because "it's been too long... you need to refile with the home warranty company." I told the person in the front office (who was instructed not to give me her first or last name) that I was not going to do that... that Cesar had provided a signed 1 year warranty that was 10 months old. Eventually she said the technician would be calling me immediately. When Cesar called me, immediately he said he was responsible for nothing. Every time I said it was a one year warranty signed by him he told me I didn't understand anything about his business. He repeatedly accused me of raising my voice, accused me of treating him like a child, and "acting just like a typical woman." His final punctuation mark was "You do what you want to do." I said, "I pick the option you said where you would come look at the parts and replace them if necessary". He would then go back into a tirade about how I didn't understand the system because it wasn't his parts that were faulty. It was something else. I'm not sure how he knew this, because he would absolutely not come to my house to look at the parts. Between 1:00 and 2:30 he would change his story every other sentence. We exchanged numerous phone calls since he repeatedly hung up on me and eventually blocked my calls. One minute he'd say he'd come out. Then he wouldn't come out. He would, but only if I would listen. He wouldn't. He would tomorrow. He couldn't tomorrow. He would in two weeks. He'd have his scheduler set something up. It might take a month. Eventually, and only because my ex-husband who does not own the house was present on the phone, he ultimately agreed to come tomorrow. Then he changed his mind and asked if I could have him come out today. He agreed to come to the house at 4:00. When I told him I had a work obligation and needed to leave by 5:30 he nearly canceled the whole appointment, telling me I was inflexible. Ultimately I had to tell him I could cancel my work requirement if it meant seeing him to honor the warranty. Miraculously he showed up in the first half hour of his two hour window, lying about a recording in his pocket which he never showed me and never legally authorized by informing me ahead of time. He has said that his parts, under warranty, are working fine and that my system, which I knew should have been replaced last year, is the problem. He said, "I don't work for you. I work for the home warranty company. I have to do what they want me to do." At one point during the times he refused to talk to me I began filing a small claims complaint and posted a negative Yelp review. He said he didn't need my business. He said his reviews were all stellar. When he saw the negative one he threatened me with legal action and said he wouldn't honor the warranty until it was taken down. I removed it, citing the answer of why as other "he's requiring me to in order to honor the one year warranty he signed ten months ago." He laughed at that. He threatened that if I posted a negative review after he came out, he would take me to court for defamation of character. I welcome that opportunity and so I'm posting my updated review. He has degraded me as a woman. He has refused to talk to me unless a man is present. He has been rude. He has lied on multiple occasions. He has not listened to me. And I will be happy to never see or hear from him again. There is no way I will ever recommend this company and will get my system replaced by a refutable company, posting a stellar review here on Yelp when that has been finished. Do NOT attempt any form of work with CES-TECH Heating and Cooling. read more

I had no idea service could be as horrendous as what I've experienced with CES-TECH, from sending over unqualified technician's to the failure to show up seven days in a row, there's no bottom in sight. They are also very untrustworthy, constantly lying and making commitments they cannot uphold. Please avoid at all cost for your sanity. read more

I love Cesar! I discovered CES-TECH by accident in 2020. I had an emergency heating problem at our apartment building. I was unable to reach my regular technician so I began searching for someone who could help. Cesar answered the phone and answered my prayers. He arrived with all the Covid protocols. He resolved my tenant's problem in no time. Fast forward to today...I had another tenant with a heating problem. I called Cesar and he was on the job within the hour. He had the part needed in his truck and made the repair without any disruption to my tenant or to my hectic day. As a property owner/manager, I value Cesar and his outstanding professionalism. He is now my go-to HVAC technician. Wonderful service!!! read more

I couldn't give this review fast enough! He showed up on a Sunday for me as well. Honest guy and He kept his word that he was going to come out on a Sunday. And didn't overcharge me! read more

Cesar arrived within a day of my inquiry, with all the necessary Covid precautions. He checked and cleaned the air conditioning units, repairing one as it had too much refigerant from a previous inspection! He able to measure the air flow from the vents throughout the house, and check the Blower on the furnace. The house is now much cooler as a result! Cesar was efficient, knowledgeable and professional, and his pricing was very reasonable. I won't hesitate to have him back to service the furnace in the winter! read more

After two previous air conditioning companies had said that I needed a new compressor, I called CES-TECH for a THIRD opinion. After about 10 minutes, they found loose wire and the problem was fixed. Excellent work. read more

I contacted CES-TECH for a second opinion after I was told from another company that I needed to replace the furnace and condenser. I called Cesar the owner on Saturday and he came to look at the unit the next day Sunday 4th of July. He was honest and gave me my options. I decided to replace my condenser instead of repairing the unit as for the furnace, it is still in good working condition. His price were reasonable so we decided to have our ducts cleaned. On the day of install, his team was very professional and explained the process of the work. If you are looking for honesty and good work, look no further. Cesar and his crew will take care of you. read more

They did not answer my repeated calls regarding the appointment. The tech doesn't show up on time. Do not waste your time booking appointments with them. read more