This company does not disappoint! Great knowledgeable technicians. There are a lot of choices,…read morebut this company is the greatest!

Hello - My name is Carly W…read more I have used this company omg- SO SO MANY TIMES. No one is better. They are QUALITY. We own over 800 rentals, we also are building out a hotel and even my own home. I use them for everything. The money you spend, is well worth the quality you get. I am grateful for this company, many contractors are SKAMMY- I can assure you, STAY COOL is not one of those. This is someone you can TRUST. And I trust no one, so that is a lot coming from me. 10/10 HIGHLY RECOMMEND! -Carly Whiteaker

these guys are the best ! didn't think they would show up on…read morethe scheduled day to install our new ac unit and furnce because it was raining...8/6/26. but @ exactly 8:00 a.m. on the dot they rang my door bell and...this is what we got friendly 5 stars prfessional 5 stars quality of work 5 stars need hvac services look no further in 2026 what a pleasure to deal with a company like this

This company is fantastic. AC went out Sunday afternoon, call Stevenson HVAC, they responded…read moreimmediately. On our doorstep 930 Monday morning. Had it running in 30 minutes. We also learned it was 26 years old, so pics were taken of AC/furnace and 6 quotes sent to us. We chose the middle of the road system, they were here Wednesday morning at 8 am to install. Estimated their installation time as 8-9 hours, but fortunately done in 6, as 15 minutes later is when all the storms and tornado warnings hit. The system is crazy efficient, we are so pleased with our choice. This must be a great company to work for, every single person we have dealt with has been friendly, professional, and has explained everything in detail. I am so impressed with this company, definitely a 10 star rating!

Jeff was very helpful and respectful he went out of his way to help us with everything that we…read moreneeded he was here on time he explained everything very well and just all around a great person to have working on your furnace and air conditioner he went out of his way to help us in every way thank you Jeff I refer anybody and everybody to use illy hvac

From the owner: Whether you're dealing with the heat of summer or the chill of winter, you depend on your heating…read moreand air system to keep you comfortable. When unexpected problems strike your home, turn to Illy HVAC in St. Peters, MO. This locally owned and operated HVAC contractor carries more than 30 years of experience in the field. Their talented technicians take pride in offering custom solutions, affordable rates, and excellent customer service. As a trusted HVAC contractor, this hometown team will exceed your expectations with timely furnace and air conditioning repairs. Seasoned technicians use the latest technology and years of expertise to fix issues with blower belts, flickering pilot lights, and worn-out ball bearings. No matter the make or model of your system, they design a personalized plan that targets the source of your troubles. If your furnace or air conditioning unit is beyond repair, take advantage of Illy HVAC's reliable installation services. Residential clients will enjoy access to energy-efficient products from Coleman®, a name-brand manufacturer. You can also pair your investment with a separate 10-year warranty plan. Routine maintenance is available on an annual and seasonal basis. Knowledgeable staff members will arrive at your home to conduct in-depth inspections, remove dirty filters, and update broken thermostats. Feel free to ask them questions regarding air purification devices and humidifiers...

Had a bigger Hvac company start servicing my new homes unit- the AC stopped working- the guy came…read moreover and said "it's an electrical wiring thing, but I don't have time to figure out what's wrong. It's too complicated. You need a new system anyway- it's old" said I needed a complete replacement because they can't service my air conditioner anymore - wanted to sell me a $10k unit. Branden came over and did a long look at my unit and agreed that it was an electrical thing- apparently he WAS willing to figure out what was going wrong- got it going again and said when it stops working again to call him so he can figure out where the wiring needed replaced. Spent a long time at my house. Well, it went out a month later and he came over and did everything he could to figure out where the wiring problem was. Took a couple visits and lots of trial fixes. Said he could service my AC just fine in the future and fixed the issue- everything working again. He also has lots of options for when I do need to replace my older system- but it's not now. Very conscientious, very knowledgeable and very patient and tries very hard to fix the problem without taking shortcuts and not wanting to do the work cares more about the customer than making a big sale.

Very great service overall but following up after an AC repair to ensure the fix was done right was…read moreabove and beyond!

Jerry Kelly installed our new HVAC System in November 2017 and has been taking excellent care of us…read moreever since. Today their very personable technician, Dillion came out to check, maintain and clean our A/C unit. Dillion did a great job, very professional, friendly, engaging and thorough. We truly appreciate everything Jerry Kelly does. We highly recommend them for your heating and cooling needs.

Just completed a very pleasant experience and bid with Mark. He's professional, thorough and…read morefriendly. However, I was not told when booking the bid that there was a $98 service charge. No reflection on Mark. He did a fantastic job reviewing my options and upselling the installation, but this vendor lost a sale. I don't do business with companies that are not up front with their charges. Mark gets 5 stars, the vendor not so much.

Our kids (3.5yo twins) clogged the downstairs bathroom with both poop and wipes. Cue the emergency…read morecall because we had no idea how bad this clog was until I tried to take care of it myself. Allen Pohlman came through within about 45 minutes of calling for assistance and got us squared away quickly and cleanly. Allen also spotted another issue and explained to my wife and me how to fix it without breaking the bank. Prices are actually really good for an emergency call. Even better, Allen was incredibly nice and not just trying to slog through another call. I'll be contacting him again if I need an assist, for sure

Great experience and results. Dan was on time and professional. He was extremely knowledgeable,…read moreand went above and beyond, really nice guy and did a great job installing my faucet, even gave me some tips about it and the dishwasher. He made sure all of my questions were answered, and everything was tested before he left. Will definitely call them for future work. Recommended!

This is sort of a double-header, and includes a review for today and from a service call about 2…read moreyears ago. This company and their techs are great. Two years ago, a day before we were supposed to head out on vacation, we found our water heater leaking. We called them, they came out quickly, got the permits they needed, and we went on vacation without having to worry about it. This morning, our furnace wasn't kicking in. No vacation plans this year, but the technicians came out quickly, found it was an in-warranty part, and got it replaced quickly. They were smart, knew what they were doing, and professional (and wore masks). We'd absolutely call Faszold first for any HVAC issues down the road. Thanks!

Called this morning and they were able to fit me in today for a service call. Their technician…read morediagnosed the problem as being a bad circuit breaker and not a furnace issue at all. I appreciated the honesty! He had to leave to get a new circuit breaker and came right back to replace it. I'm happy with the service - prompt and courteous - but I am not thrilled with the high cost. The service call was $89 and a new circuit breaker should cost only $20-$30. I was charged $331.50 total, which I've been told by neighbors is very, very high for such a simple fix...Oh well. At least my furnace turns on now.

Excellent experience with Rich. Needed gas line capped, water expansion tank replaced and tub…read morefaucet replaced. Same day service. Honest and up front with pricing.

In November 2025, I called this company to inspect my AC/heating unit. The technician upsold me on…read morea heating and cooling maintenance package, explaining that it was the best thing I could do for the unit, so I purchased it. He also told me I needed new filters, which I went out and purchased, and he installed them. He was very friendly, so I felt confident that everything had been taken care of. Since it was winter, we only used the heating portion of the system, and it worked fine. We had no need to turn on the air conditioning until two days ago. When we finally turned on the cooling system, we discovered that it was not cooling at all. I contacted the company because it appeared that either the cooling maintenance had not been performed properly or it failed to identify an issue that already existed. If the cooling system had been inspected as part of the maintenance package I paid for, I would have expected any needed repairs or replacement parts to have been identified at that time, especially since the technician had no problem recommending and selling additional items during the original visit. When I called, I was told that I would need to pay an additional $99 service fee just for someone to come out and look at the unit. I explained that I had already paid over $200 for a heating and cooling maintenance package and wanted to understand why I was being charged another fee when the cooling side of the service had not resolved or identified the problem. Instead of addressing my concerns, the representative raised her voice and repeatedly told me that the only way the company would come out was if I paid the $99 dispatch fee. Based on my experience, this company's business model seems heavily focused on upselling and generating additional service charges. I would not recommend this company and believe customers should be cautious before purchasing their maintenance packages.

So, let's start with a 'complaint', the AC they installed in June stopped working. I put complaint…read morein quotes though, because a problem is less important than the service, at around 7 I sent them a service request through their site, 7:30 I got a call telling me they'd have a tech out between 9 and 12. Yes, that fast without me requesting emergency service. And they had already had looked up my account and knew that this is a warranty job. Seriously, I thought the install was well done, 2 man crew, and maybe 8 hours, a very well organized job. Seriously, you need AC or heat work, call them, you won't regret it.

I have been using Welch for approximately 5 years now. I had left my previous company due to…read moremanagement changeover and merging with another company. A neighbor recommended Welsch to me and I could not be more satisfied . I have a big home with 3 air conditioners and 3 furnaces, so I rely on them to keep working. Colin is our service person, and he is "the bomb". He is always on time, extremely good at what he does, very very thorough, and respectful to not only my husband and I, but treats my house respectfully also. I have one unit in the attic, and he never complains about crawling up that ladder in the heat to check it out. My pricing is a bit more due to the number of units I have, but the quality of service and respect is so worth it. The office staff is very organized also, and always kind /nice when scheduling or troubleshooting a problem.