I just really appreciated what seems like an honest assessment. I was looking for a second opinion,…read morebecause two other companies had recommended major, costly repairs or replacement for my gas furnace. The Grenz folks came, carefully looked at the unit, and said, "If it were my furnace, I wouldn't do anything. It is running the way it's supposed to." This second opinion cost me something, naturally, but it also saved me between $5,500 and $19,500 (two quotes from the other two companies). Jim seems like a straight shooter. I'd recommend you give these folks a try.

He called me back and talked me through the fix. He did not wait to come out and wouldn't take any…read morepayment for his assistance. He clearly knew what he was doing. He was able to talk me through several troubleshooting exercises without seeing the gas fireplace itself. If I have any HVAC or fireplace needs in the future, I will definitely use Grenz

We have done business with Kleckers on 2 occasions. First they installed a brand new furnace with…read morean Aprilaire air filtration system (about 2 years ago) and a new thermostat and that has worked flawlessly and is easy as it gets to operate. Then late this Spring we had them replace our old central air conditioner, and that works like champ also. They are very professional and take care of their customers - if anything is wrong they will fix it. Both installations went flawlessly for us and the units work perfectly. A++

AS A DISABLE Vietnam Military Veteran I was robbed, scammed, by Klecker's Heating and Air…read moreConditioning demanded $700.00 for one of their Technician who worked on my Air Conditioner for a little over two hours and never fixed it. I had to call someone else who only charged me $176.00 and fixed it. Klecker's Technician must of hated his job. He was very RUDE, DISRESPECTFUL, and kept wanting to use my bathroom while smoking a pipe. If he hates his job so much, why is he still working their.

I have dealt with a lot of furnace and water heating guys over the years and I THANK GOD I found…read moreMARK. He is one of the most honest and hard working guys I met. I had a furnace go last year and gave him a call because friend said he did good work. He was out the next day and walked us through what would fit the house and what would fit my pocket book. Last week my HOT water went and he gave me a call back and said he was in the area next day. He was on time and fixed it in a flash. He is also clean and handles himself as a true gentleman. I am over in Beaverdam and I recommend Mark anytime ! Great experience both times

Fiedler heating has been repairing my furnace for almost 9 years. He's always been quick to respond…read moreeven though I don't have children he makes an extra effort to get to homes with failed heating for families that have children. Even when my furnace wasn't installed by him originally he managed to keep it running until I ended up replacing my my furnace with a new one that of course he installed. I could not be happier with his service and I'd recommend it to you. Mark gave me a great deal on a high-efficiency furnace that replaced my 24-year old one and reduce my heating bill.

Had a frozen pipe and couldn't figure out where. Called and had service in about an hour! Tech…read moreBalen was SUPER helpful and gave me tips to help prevent it happening again. 100% will call again for any plumbing needs.

Their quote was 2.5 times higher than two other local businesses!! Absurdly high! No way was the…read moreamount of work I was estimating worth the same às a slightly used car! $9k for what is probably 2-3h work is laughable!!! This makes me wonder what they are charging other people who haven't researched the things they want to the same degree I have. It's almost criminal. Their estimator was very pleasant, though. And their communication is quite good. Maybe that's where the extra $5k is required!!!.... Complete BS

We called Pat's to diagnose and repair our boiler, which decided to crap out on us on a Sunday. The…read moretech, Michael quickly gave us a call back, and within an hour he arrived at our place. Michael not only diagnosed and repaired the boiler in record time, but he was also kind enough to take the time to thoroughly explain how a hydronic heater works, and all of the necessary maintenance involved. Michael was extremely knowledgeable with all things HVAC. We were charged a very fair price for the labor, especially considering the weekend callout. Fast forward a few weeks, and we called out Michael to update some of the heater controls. Again, Michael provided outstanding service and corrected a few other issues with our hydronic system. Still highly recommended!

Update 4-14-2026 To finalize this exchange and summarize…read morePat's treatment of my family and I. I have been extorted by Robert, accused of fluffing the bill, and essentially told that due to Pat's mistakes I am no longer welcome to use the service. This last part is verifiable in the response given to me. To whomever is above Robert I want to clarify how this situation was 100% caused by your company and now I am being painted to be the villain. If you pull the phone record you will hear that my family and I never once asked for a discount. In fact Robert was adamant he make it right and reactively (as this was after the first screw up) offered to take this job on the chin. I encourage you to ask Michael, as he is a super honest employee of the conversations we had with him as he made a mistake and misquoted. I assure you he will be nothing but truthful regardless if he made the blunder. With all this being said I am now not welcome to use your service according to the Google commentator. For that I am bummed as the workmanship, when Pat's does show up has been historically a class act. I have contacted the BBB, and Angie's list due to the extortion and treatment by Robert and Pat's heating as a whole. I do not care what the outcome is but to sit back and be bullied due to Pat's mistakes, and Robert's incompetence is absolutely ludacris. To the owner, if you want to make right terminate Robert's employment and I would be more then willing to continue business as my family has done so for the last 20 years. Robert has done nothing, and I mean nothing to make any of this experience pleasurable. Even eating the job, which your team did as Robert promised, came at the expense of extortion, and painting my family and I as the villain. I must say that the treatment of my wife and dying father (the one sitting home waiting for Pats delaying treatments to be available) lead me to get involved. The owner is welcome to call my dad and he will give you my number. I will not discuss anything with Robert as 99% of these issues came from his failed management. To any users reading this know I do this to show you the caliber of people Pat's employees. In the unfortunate event an issue does arise that is out of your control it is evident Robert will say whatever it takes to try fixing the solution but do minimal to help. A liar is a liar, beware before making any Deals with him and I will encourage anyone to get anything he says in writing to expedite the back and forth I had to do to get him to honor his commitment.

WOW!! RUN!! Don't walk!! These guys are AMAZING!! So.... I live in a condo complex that…read morewas built in 1988. The owners were instructed that we needed to have our dryer vents brought "up to code" as most of the vents had become disconnected... and were venting somewhere inside the building.. but not venting out side the the building. Argh... a challenging task for sure. I called several companies to come out and give me an estimate. Every single company I called said "I will find your disconnect, but you are responsible for replacing your drywall, painting, etc" Not good news. Then... Ducts On Call came out... and they spent 4 hours researching... trying to figure out which vent was mine that exited out of the back of the building. But since every single dryer vent was disconnected in the interior of the building... there was NO way they could figure it out without tearing up the ceiling in mine, and my neighbors units. I was SO frustrated. But then Nick suggested we put in a new vent duct from my unit straight out the front of the building. It was my only option. He said we would need to schedule a time in the future... but I told him I needed it done in the next 3 weeks. He said... "I will make this happen for you" Well for starters... he DID NOT CHARGE ME for the 4 hours he spent trying to figure out which vent was mine. HE SAID... "I didn't solve the problem.. so I will not charge you" What?? 4 hours of your time for free?? Moving forward..... Nick and his crew came back 2 weeks later to install my NEW, up to code dryer duct on a new path out the front of my condo. I was SO not looking forward to having my ceiling ripped open to have the duct installed. So the day had come. Nick arrived before his scheduled time and he went to to work. I asked him... "How much of my ceiling do you need to open up?" He said... "I'm not opening your ceiling... I'm going to drill a hole in the exterior of your building, and slide the new duct straight back to your dryer connection" I was beside myself! I could go on and on... but let me tell you, this guy is the real deal!! He is incredibly gifted at what he does... super friendly... hard worker, and gets the shit done!! For what I thought was going to be a day of HELL... turned out to be a day of BLISS. I CAN NOT recommend this company any more than I do!! They were AMAZING... and the job was smooth, and quick, and so much easier than I dreamed it would be. Let me state again... that I called several companies to get the job done.... and these guys were one of the newer companies I called.... but I hit the jackpot!! Trust me!! If your need Duct work done... these guys were stellar from start to finish. And no... I'm not related to them... I'm not his high school friend... and I knew nothing about them, but I took a chance... and boy... am I glad I did. Amazing! THESE GUYS KICK ASS!! Give them a try!! Thank You Ducts On Call!!

OMG, these guys are great! Nick and Kim are awesome! My son in law blew out our dyer vents and…read moredidn't get the pipes put back together. Took Nick & Kim like 5 minutes to reattach everything at no charge!

AC was out. They said we had a leak and either $3000 to repair or $8000 to replace. Plus they…read morechanged out our thermostat for No Reason and it sucks: no directions given. We got a Second opinion and for $700 they fixed it!

We had a new furnace installed in 2023 and a new air conditioner in 2024. We signed up for the…read moreannual "Maintenance Agreement". Well, we are 100% satisfied with the quality of workmanship, professionalism, prompt service, friendly attitude and excellent products sold. We have never needed a service call on either machines to date. The annual maintenance is such an outstanding offer. It gives you peace of mind that your investment is being taken care of. I would love to recognize Ray Seeber, our technician for his outstanding quality of work. He was so informative, patient and respectful. Thank you Ray, we look forward to seeing you again. Kettle Moraine, you are certainly the BEST!!!! Mr.& Mrs. O'Brien