About

Home 5 About

About Grenz Service Company LLC

Excellence Since 1987

At Grenz Service Company, LLC, excellence has been our hallmark since 1987. As a family-owned and operated business, we’ve proudly served the Waukesha and Jefferson County areas, delivering friendly, dependable heating and cooling solutions to both homes and businesses.

Our Mission

Our mission is to provide top-quality HVAC services with integrity and a personal touch. Led by founder Jim Grenz, Sr., and his son Jim Grenz, Jr., we specialize in:

Commercial and residential service on all makes and models
Air conditioner and furnace repair
Maintenance on all brands of air conditioners, heat pumps, and furnaces
Installation and service on commercial refrigeration equipment, including walk-in and reach-in freezers and coolers, back bars, and ice machines
Gas fireplace service and maintenance

Our continuously trained staff is always ready to answer your questions, ensuring you receive the most performance, value, and peace of mind possible.

What Sets Us Apart

Reliability: You can count on us to be there when it matters most.
Transparency: Clear communication and honest pricing come standard.
Expertise: Our team undergoes rigorous training to stay updated with the latest HVAC technologies.
Customer-Centric Approach: We treat our customers the way we’d like to be treated—showing up on time, being prepared, doing quality work, and treating your home as if it were our own.

Our Commitment

We are proud to be an independent dealer of Trane products, excelling in their installation and service. Our helpful staff is always on standby to answer any questions, and we offer the proven quality of top brand names to ensure that you get the most performance, value, and peace of mind possible.

Beautiful living room interior with tall vaulted ceiling, loft area, hardwood floors and fireplace in new luxury home. Has large bank of windows

Testimonials

SEE WHAT YOUR NEIGHBORS ARE SAYING ABOUT Grenz Service Company LLC

Google Rating

5.0

Based on 222 reviews

Grenz Service Company LLC

5.0

Jason Kofroth

12:58 23 Jun 25

Grenz provides great service at a great price.

Matt Hannon

18:25 22 Jun 25

Jim Grenz recently serviced our gas fireplace and I cannot say enough good things about the experience. He did a great job explaining what he was doing and the work he completed. I didn’t realize how much better the fireplace would look and function after the tuneup. His attention to detail and overall pride in his work was very evident and refreshing. Please continue to support great small businesses such as Grenz. Thank you Jim.

Scott

13:32 22 Jun 25

Hit all the marks. Sterling, Would highly recommend!

Kirk Farber

22:59 21 Jun 25

Very professional, knowledgeable, fast, and friendly. Highly recommended!

Eric Chapman

22:21 19 Jun 25

Pat Hawley

01:51 19 Jun 25

Grenz was responsive from my initial inquiry - they texted and called back immediately (it was after hours), they scheduled a 2-hour time window for the next day, showed up on time, and efficiently diagnosed and fixed our ac. They also did a nice job explaining the issues and what they suggested for repairs. Great job - I highly recommend them.

Renee Browning

23:46 18 Jun 25

Everything was great! He was on time, worked quickly and was very professional! Would definitely recommend!

Jessica Lange

20:14 15 Jun 25

Always prompt & kind. Service and quality of work are excellent.

Richard Dykowski

14:54 13 Jun 25

We had five contractors provide quotes for a complete furnace / AC / thermostat replacement. Pricewise, Grenz was squarely in the middle, even though they quoted a premium product. Jim walked us through the entire removal and instation process, including how and where they would relocate equipment, how to program the thermostat, and maintenance requirements. He made us extremely comfortable with both the equipment and their process. They arrived on time and cleaned-up thoroughly. Highly recommended.

Bonnie Blair Cruikshank

00:17 12 Jun 25

Grenz has been reliable for years and why we still use them!!

Laura Steininger

14:20 10 Jun 25

Bradley Locke

17:59 08 Jun 25

Grenz technicians did an excellent job of quickly diagnosing the problem, installing the replacement capacitor and getting the AC back online in a jiffy. Have used Grenz for years and will continue to do so. I recommend Grenz to everyone I know.

Jan Pearce

20:19 04 Jun 25

Mike Kujawa

14:38 02 Jun 25

Linda Douglas

19:58 28 May 25

Gave us options instead of completely replacing entire system

Matt Dawson

13:54 23 May 25

Great service and great guys. When a piece of equipment breaks down they are usually there pretty quickly and get the pizzas flowing again.

Robert Crabb

17:52 22 May 25

Michael Remitz

21:06 20 May 25

Best service in town and very good people

John Leidel

18:37 19 May 25

Fast, professional work. Very knowledgeable and experienced we have become a regular customer for our refrigeration needs.

Chad Wuestenberg

18:35 18 May 25

mary cunningham

00:16 17 May 25

This team is fantastic! Always a quick response and a fair remedy to every problems! Highly recommend them!!

James Lewandowski

23:53 16 May 25

Excellent service, great people and price.

Deana Nolde

11:09 16 May 25

Had some gas fireplace issues this past winter and Grenz came out to fix. They were very knowledgeable and friendly, fair price as well. Was very pleased with their service that this spring I chose Grenz to replace my furnace and A/C unit. Again, very knowledgeable, good customer service, prompt, fair price, install went smoothly and they sell quality products! Owners are very hands on with their business, I'm impressed!

Duke Cami

22:46 15 May 25

Got us back up and running in a flash.GRENZ will be my first call next time I need a cooler ect fixed.

Lynn Zwaska

14:19 12 May 25

Linda Miller

18:24 25 Apr 25

I highly recommend Grenz Service Company. Grenz has serviced my air conditioner and furnace for a number of years.I have found the entire staff to be honest, reliable and customer focused. Fantastic company.

CarriUSA

19:49 08 Apr 25

Professional, clean, honest, quality, and reasonable. We have Trane for heating and central air. I researched brands and hands down Trane/AmericanStandard is by far the best and reliable. Our central air unit ran out of Freon/ leak and had a few contractors come out trying to sell us on units that did not fit our needs, but was way more costly. We just wanted a reliable well made central Air unit that worked with our home. Grenz did not over sell on something we did not need, was professional, friendly, honest, and explained everything throughly and no jagging us around , put a new pad in, new drain, quality installation, and cleaned up after themselves<<<

Chris Tarnowski

17:06 04 Apr 25

All new HVAC equipment installed. Very professional and personal experience. Very cleanly. I was able to order and have it installed in about 1 week. So far extremely satisfied with the equipment. Highly recommend Grenz Service Company LLC.

Genevieve Swanson

22:27 05 Mar 25

Very hard to find people out there with the knowledge, experience and integrity like Jim Jr has. He come out to give us a quote on an ERV, instead he noticed that our fresh air intake was closed. It’s been a couple of weeks with fan running and air inside home is so much better!! We are forever grateful for his service! Highly recommend Grenz! (Wish our builder had given us info on fresh air intake.)

M K

18:57 04 Feb 25

Jim Jr. and his associate came by promptly (excellent!!!) and looked at our ice maker. I was so pleased to have our options and a lot of details laid out in a clear way. No repair needed, but I know where I’ll be going when the day comes to replace our current unit. Excellent, honest, reliable service. Highly recommend and highly appreciated. Many thanks for a great experience.

B W

17:40 22 Jan 25

Cannot say enough good things about this company and Jim Junior. Amazing customer service, great at helping walk you through your house and issues and would strongly recommend them to anyone asking.

Cal Williams

21:33 13 Jan 25

Jim and Bo did a great job! Very professional and worked diligently to get our fireplace up and running. Fair price for the work performed. Would highly recommend!

Jennifer Lanser

18:30 06 Jan 25

We leveraged Grenz Services for a gas fireplace tune-up. Service was quick, easy, and efficient with a fair price.

Anthony Stanley

18:14 02 Jan 25

We live in Elm Grove and needed our gas fireplace inspected/serviced/tuned up. The Grenz team showed up on-time, gave us tips/tricks for maintaining our fireplace, and completed the work quickly. We would HIGHLY recommend their services.

Ryan Kuhn

15:47 20 Sep 24

Update, Sep 2024:I went with Grenz for a new American Standard furnace and air conditioner. They were very professional, had quality workmanship and the pricing was fair. They strived to ensure the install was clean and neat. I also appreciated their technical expertise and how they keep up on continuing education in the industry. Finally, Jim was very transparent throughout the entire process. Highly recommend!Original Review, 2020:Great serviceI appreciated how engaging James was during the service call. He showed me in detail how a pressure switch failed which prevented the furnace from going into stage 2 heating. He also showed me what was causing a humidifier leak and how to replace the humidifier filter. Overall, Grenz seemed pretty honest and fair. I'll probably continue using them for future service.

Jason Dahlgren

20:39 17 Aug 24

We’ve been working with jim and the Grenz family for a number of years now. We recently had them install a new furnace and ac unit at our new residence. They were very professional, clean, and considerate while accommodating our family needs through out the install. They were transparent, honest and eager to answer questions while we were evaluating options. Overall great to work with, I would (and have) highly recommend.

Zach Jarecki

13:36 17 Aug 24

Steven De Sota

21:40 20 Jun 24

Jim Jr and the entire Grenz crew were awesome. Jim was very informative and knowledgeable about the American Standard furnace and air conditioning system. He was able to explain in simple terms and at a higher level as well. The install when perfect and we are now sitting comfortably in our air conditioned home.

David Hanscom

11:23 18 Jun 24

Grenz Service company is very professional and honest! We had a great experience working with them and they absolutely rocked out the job! They had our furnace, AC and smart thermostat swapped out running in less then 8 hours. We are very happy we chose them to work with and will continue to use for anything HVAC related in the future!!!

John Kaczmarek

14:50 17 Jun 24

We recently had our furnace and a/c replaced by Grenz Service Company. They came highly recommended and we are very happy with their installation. The entire crew was efficient and professional. Before leaving the new equipment was thoroughly explained to be sure that we knew how to operate it. They are definitely the company to choose for your heating and cooling needs.

Ryan Larson

00:56 14 Jun 24

Would highly recommend, very knowledgeable!

Robert Graser

00:23 26 Mar 24

Needed to replace a worn out furnace and A/C after it died one cool morning. I took 5 different bids that were all within a couple hundred dollars of each other. I contact Jim Grenz because he does all the HVAC service at the Fire Dept that I work at. Jim Grenz was able to take time out of his vacation too give me a bid. I was so impressed by the work force that showed up the next day and the quality of the work that was done was very impressive. Thanks to the Whole Grenz family. I would recommend them for your heating and cooling needs

Steve Kinsey

18:19 15 Feb 24

I've been using Grenz Service for my business going on 8 years now. They have always been there for me.

Darrell Clayton

18:55 20 Dec 23

Came in and fixed my gas fire place in about two hours, this was after I had a different company out and they said it was unfixable. Great service would highly recommend. We will definitely be using Grenz to service all of our HVAC systems.

David Medici

14:01 15 Oct 23

Grenz Service Company recently did two jobs at my home.The first was installing a new HVAC system. Jim Grenz walked me through all the options and provided me with three quotes, each depending on the low, medium, or high grade HVAC that were recommended. They answered all my questions, did the install in one afternoon, and even entertained my questions and requests for system configuration tutorial. Awesome!The second was a repair to my gas fireplace. The pilot light had just aged, and my penchant for turning off the pilot after winter was not a good idea. Again, the service was excellent.I would highly recommend Grenz Service Company. Great products, great service, great prices.

P V

20:21 10 Aug 23

Right on time, outstanding work. Could not be happier.Thanks Jim!

Kate

18:43 04 Aug 23

I feel like I would trust Jim Jr. with my life, such is the level of care and exceptional service he and his team provide. When it comes to potential fire risk or refrigerant leak, I feel confident to sleep soundly again after Jim has reviewed and repaired any issues.In purchasing my condo, I took ownership of my first "Magic Pack" heat/AC combo unit, which is a bit intimidating for a new home owner. I have had Jim Jr over for 2 separate issues and each visit he took the time and utmost care to resolve those problems with the AC, and didn't leave until he was satisfied that everything was tested and running properly.Jim Jr. offers a caliper of service we rarely see these days; he willingly shares his vast knowledge to help educate us on what is "normal" and what to look out for with this unique HVAC system. He is patient, kind, optimistic, and so hard-working!Thank you so much for everything, Jim Jr! GRENZ is #1 in the lake country area and I would highly refer this business.

Lainie Andringa

00:18 01 Aug 23

Justin Reedy

17:37 31 Jul 23

Great to have a knowledgeable HVAC technician work on our system. Same day service, promptly figured out the problem and explained everything to me in terms I could understand. Working with Jim from Grenz Service was painless and professional. Highly recommend this company!

Julie Klinger

14:29 09 Jun 23

They called back very quickly to schedule appt. Technician was very friendly and knowledgeable. Very reasonable cost also. 100% recommend them.

John George

14:18 31 May 23

Nicholas

18:15 30 May 23

Very professional, very thoughtful of my time and was able to diagnose/solve the problem within a half an hour of arriving. Fully recommend.

Jonathan Doyle

14:31 24 May 23

Andrew Riese

16:43 19 May 23

Our air conditioner and furnace were 30 years old and both went out around the same time. Luckily my father in law gave me a good recommendation to call Grenz. He had hired them in the past and had great things to say. I can see why he said those things.They installed a brand new furnace and A/C all in one day. We got a quote from another company before hiring Grenz and they made no mention of needing to change and upgrade some of the duct work so that way our huge purchase isn’t hampered by the ducts. We then asked Grenz to give us a quote and I was so impressed with the attention to detail, use of actual math and measurements to determine what is needed for us, and the clarity it was communicated with so we could clearly understand what we need to do. I have 100% confidence they installed everything as well as you’d want a company to do.They were extremely courteous, smart, and professional. They also respond to any questions as quick as I’ve ever seen a company respond. The time in between the quote and actual install was super quick so that we weren’t left being sweaty and uncomfortable until they had time to do our job. Overall I have only great things to say about them and their work. It’s a father and son operation and you can clearly see that this is their life’s work based on the care and attention to detail. I’m glad we gave our business to them and will be giving it to them in the future for anything HVAC related.

Patti Walsh

21:47 08 May 23

Grenz svs has maintained my older HVAC systems annually until their age finally caused failure - they have just replaced my HVAC systems - it was quick and clean - I feel confident in their recommends for replacement equipment - I referred them to my neighbor as well and they too were impressed with their service

Andrew Richter

11:53 06 Apr 23

From start to finish, Grenz was clearly a head above the rest. THIS IS NOT A SALES ORGANIZATION. Their dedication to service is a clear exception to today's standards.We purchased American Standard's premium modulating furnace, premium variable a/c unit and coil, a new filter housing, an advanced home comfort control, and a uv light ionizer to sanitize all the air we breathe. American Standard performs ridiculous, rigorous testing on their equipment and builds their units to outlast the rest. Once we found the best product, we searched for the best and most reliable service. You never know for certain what you're going to get. Rest assured. Grenz and American Standard will not let you down.I was blessed with the opportunity to consult our project with Jim Jr. I'm a little overbearing, and Jim was right there to help me with every question and request. I like to get off into the weeds. Jim understood this and took me all the way, breaking as he went to ensure we were still together. It's exactly what I needed. Everyone else just looked for my hot buttons and dropped sales lines to see if I'd bite on their pitch. That's not what I was looking for. Give me a good education so I can make an educated decision. Please leave the fluff at home.Grenz showed up exactly when they said they would. They brought the exact equipment we agreed upon. They performed the exact installation without fault - clean and correct, the first time. They even finished early. Jim took the time to walk us through every setting and adjustment available on the control unit (thermostat and more). He performed a final walkthrough and followed up the next day to ensure our satisfaction.Grenz may not be the only incredibly solid HVAC contractor left in the market, but you may need a treasure map to find the others.No sales.Just service.We are customers for life.Thank you for being you, Jim, and Grenz Service Company.

Chris Nelson

18:12 22 Feb 23

No one wants an unexpected expense, but Grenz took some of the sting out with their awesome service. Same day service for a downed furnace, and it was more affordable than I had expected. Jim Jr. was awesome from start to finish, and I will be using them for my HVAC needs in the future (and recommending them to everyone I can).

Peter Sholts

05:20 09 Feb 23

Working with Grenz was amazing. I think I called on a Friday to ask about a whole home humidifier and the phone consult was great, the price was reasonable and in less than a week the system was installed. Jim Jr. and the two younger guys he brought with for training were exceptional. The quality of the work was awesome. Grenz is our go-to HVAC company going forward.

Alex Young

14:31 29 Jan 23

Very responsive to our serivce call. Went above and beyond on the weekend, outside of hours! Highly recommend! Affordable, fair pricing! P

Cheri Kersey

14:07 10 Jan 23

We dealt directly with the owner and were quite impressed We would definitely use them again!

Charla J Owens

21:46 09 Jan 23

I am extremely pleased with Grenz Service Co! My furnace decided to just quit working one night, & Grenz was there the following morning to fix it. Unlike other companies who are just interested in getting your money, Jim Jr did all he could to keep from having to replace it (with the knowledge that it may be a distinct possibility, depending on what happens...). It worked great for 2 days...it was time to replace. Fortunately, he was able to squeeze me in the next day! He was prompt, responsive & incredibly helpful. Once they got the new furnace installed, all was well (& warm). 🙂 I will definitely use Grenz Service again & refer them to anyone in need! Thank you for making a bad situation so much better!!

David Held

19:29 09 Jan 23

Grenz Service Company did a great job installing my new furnaces and air conditioners. They were on time, completed all the work as stated, cleaned up afterwards and took the time to explain the system and answer any questions. I would highly recommend them for your HVAC needs.

Erik Gardner

19:27 09 Jan 23

Jim and the Grenz team are everything you want in a heating/AC company. Responsive. Professional. Attentive. Would recommend to anyone.

red Danni

18:00 12 Oct 22

Firstly, thank you Google reviews for having this review service. When our furnace started acting glitchie, no heat, October in WI, not good, we didn't have a clue as to who to call. So onto local HVAC businesses with good reviews. Found Grenz, just a few miles from us. Called us back within minutes and was able to setup an appointment the next day. He called 10 minutes before arriving and was right on time. He checked every aspect of our 30 year old furnace, which we try to maintain and also have a Honeywell whole-home air cleaner on. Turns out it was just accumulated dirt and dust in areas the filter doesn't involve. A dirty pilot assembly. Quick and efficient, fair and reasonable. You hear horror stories of costly repairs and parts that may or may not have needed replacing. The furnace is 30 years old and you'd think something could have needed replacing. But no, just cleaned it and said it's good! Totally. Impressed! And Houston, we have heat!!! Thank you Grenz, you get 10 stars.

Suzanne S

23:12 02 Sep 22

Excellent service and extremely knowledgeable! A different company had installed our AC over a year ago, but we were having problems that the original installer could not figure out. We called Grenz - they figured out the problem immediately and fixed it. Highly recommend Grenz - would not go anywhere else. Very courteous and professional too.

Jeff Mitchell

19:24 30 Jul 22

Honest, earnest and good advice

J K

19:45 12 Jul 22

We were having issues with our existing equipment. The guys at Grenz Service came out and replaced with new AC, we were up and running in no time!

Nadia Koepke

01:29 06 Jul 22

My experience with Jim and Grenz has been absolutely amazing. Jim is so responsive and goes above and beyond taking his time to explain what happened what needs to be fixed and what the homeowner can do to keep the systems running smoothly. Highly recommend Grenz!!!

Gregg Eisenhardt

01:21 17 May 22

Lori G

20:16 23 Feb 22

Same day service for a furnace that wasn't working!!! Jim was friendly and knowledgeable.

ERNIE CLAUTIER

14:52 21 Feb 22

They were prompt and very personable. They did not try to sell you up, Instead they gave all options for repair. Their knowledge on the unit was impressive.I will use them in the future.

Andrew Stoker

01:15 21 Jan 22

Very happy with my experience. We have a 25+ year old furnace that wasn’t putting out any heat. A technician came out right away and thoroughly serviced it and got it running again.

J S

19:17 26 Dec 21

Had a furnace problem 2 days before Christmas-went above and beyond-even driving to Appleton for the part we needed! Great service. Fair priced. Would call them again-but hopefully won't have to!

P Rubert

15:18 18 Nov 21

Grenz Service Co. installed a new boiler system at our Lodge. Jim Grenz presented our group a recommendation on which system would be a good fit for our building and needs. Once we decided to move forward he was able to place a hold on the new boiler with the manufacturer during a time of short supply. The Grenz crew was able to remove the old boiler and installed the new system in one morning. Everything was handled very professionally and the system is working great! Jim made himself available to answer all our questions before and after the installation. It couldn't have been any easier!

Dave O'Brien

06:29 18 Nov 21

We’ve been customers for two years now. Very happy with our annual service of our furnace and A/C. Bill has been our tech. Always personable and informative. You can tell he takes pride in taking care of his customers. He takes the time to do the job right and values his customers money as if it were his own. I highly recommend Grenz without any hesitation.

The Dragon

13:54 05 Nov 21

Have used Grenz Service for NEW EQUIPMENT and ANNUAL MAINTENANCE. Can't say enough about their service, honesty and integrity. All service personnel should be so easy to work with. Thank you Grenz for all you do. Would highly recommend. Dianne

Dawn Degner

15:28 19 Oct 21

Kept in touch when running late because of emergency furnace repair. Cleaned pilot light element so flame wasn't as huge, checked all elements involved in gas fireplace function and replaced light switch connected to gas fireplace. Taught me a fact about GFCI outlets I wasn't aware of.

Brent Sumner

15:02 04 Oct 21

Great Service. Thanks.

Pamela Martino

20:28 01 Sep 21

Josef Pelc

12:09 11 Aug 21

Very professional service, highly recommend.

Stephen Lauber

16:10 26 Jul 21

Bill Perinovic

17:04 21 Jul 21

Michael Laabs

13:24 11 Jul 21

Performed a very thorough check of my heating and A/C systems. Very knowledgeable and answered a number of questions I had. Reasonable prices for the work performed. Very happy to continue using Grenz for future work!

Eric Chapman

19:51 22 Jun 21

Guys are very knowledgeable about their products always good at communicating very good work on the job would recommend.

Natalie Kieffer

15:08 15 Jun 21

Steve Roehm

20:34 11 Jun 21

Jim serviced our AC Unit. He was extremely Professional and Courteous! He told us was what we needed and he helped us keep the costs contained to the minimum required. We really appreciated his honesty and integrity! We will use Grenz from now on!!!

clayton webber

19:34 03 Jun 21

We recommend Grenz Service. Probably like yourself having AC installed is not a frequent experience. They took the time to educate me and show my options, which also included a cost savings recommendation on why a higher end unit that they offer would not have a good ROI for us here in Wisconsin. They proactively communicated on a possible late part which ended up arriving on time. For the day of service they called to see if they could come EARLY!, how often does that happen. I also explored other companies which took a while to call back and never called. I am happy with my service and will use Grenz again.

Brian Hastings

11:33 31 May 21

Local to Delafield small business. Responsive and excellent customer service. Thoroughly explains the situation in simple terms before proceeding with any expensive work. Highly recommended!

Andrea Fleisher

17:57 12 May 21

L. Schultz

23:17 26 Apr 21

We chose Grenz to do a heating/cooling overhaul for our home, purchasing and having a new heating/AC system installed, duct work replaced, and additionally installing a ductless mini-split system. I was able to stay home and observe a crew of three talented and experienced people as they dedicated the better part of four days to install what was a custom designed system to manage air and temperature control in our 150+ year old house. It was marvelous to witness how professionals fabricate and adjusted new state-of-the-art equipment to not only handle air efficiently, covering all the details to optimize functionality and yet make it look good, so you feel like you're making an investment, not just simply replacing necessary utilitarian equipment.The company owners gave us the special attention I know they give everyone. We went with their main recommended product, American Standard furnace and AC. During the process I asked why it is the brand they handle. The reply was their business decided they really prefer not to have to do warranty repair work. While they certainly honor warranties, they have found American Standard quality and durability design is such that customers very seldom require warranty repairs.Because of the unique nature of our old house a ductless mini-split system was chosen to handle most of the heating and cooling in the upstairs areas. It is a combined AC and Heat pump, and relatively new technology. It worked out well as a choice as duct work would have been very difficult on the second floor. The supply lines to the cooling/heating heads inside need to run outside along the building, and once again, in addition to proper operation consideration, Grenz made those lines unobtrusive or blended in with deference to the homes aesthetics.Grenz pricing is competitive, and you can feel assured you will get what you pay for and a bit more in quality and detail. They are top notch, and I would without reservation recommend them to future customers.

Jim Wambold

12:36 20 Apr 21

Jim and his crew are very professional. The work done is done right at a fair price.

Terrance Brooks

13:41 15 Mar 21

Jim Grenz does excellent work at a fair price.He took the time to explain what and why he was doing the necessary maintenance. He took the time to answer my questions. I highly recommend Grens Service

Jennifer Ecker

21:33 16 Feb 21

He was able to come out the next day, unlike others I called. He made the repairs quickly and the cost was very reasonable. The fireplace has worked great since!

Charles Yee

20:29 23 Jan 21

Grenz service company is by far the best in commercial refrigeration repair. I have been a customer of theirs' for over 15 years. What l like the most is that he comes in, makes a quick diagnosis and fixes what is wrong. He doesn't hang around and charge you for services you don't need. His charge for services is very reasonable.

Jan Wenzler

18:39 20 Jan 21

Prompt response to our call and found issue quickly. Performed maintenance check up while here. Awesome service! Highly recommend!

Wendy Medlock

19:17 19 Jan 21

Amazing service. They were here during the time frame promised.Our gas fireplace was collecting gas and would light with a large boom.Inspected the unit and then walked me through what they thought was wrong and why. Cleaned the suspected part and it was fixed.Can't say enough about these guys. It was like having a caring family member in our home.

Holly Hoffe

18:01 19 Jan 21

Always friendly, always professional and positive and always willing to explain/show/discuss problems and workings and what's being done.

Barbara Pinekenstein

22:23 29 Dec 20

Excellent service. Repaired the furnace and installed a new humidifier. Good communication and very responsive.Extremely dependable. Calls for service promptly returned. Very professional. Highly recommend

Derek Schreiber

16:09 11 Dec 20

Great service and explanations of what was done! Very professional and for the price it was a great value. Would highly recommend!

Sean Jones

18:37 16 Nov 20

This company is awesome. They are highly professional, responsive and a true small business to business partner! There rates are very reasonable! They have made repairs for us and we have them contracted for regularly scheduled maintenance. They have saved us thousands. We highly recommend!!!

See all reviews Write a review

Leave a Review

Jason K.

12:58 23 Jun 25

Grenz provides great service at a great price.

Matt H.

18:25 22 Jun 25

Jim Grenz recently serviced our gas fireplace and... I cannot say enough good things about the experience. He did a great job explaining what he was doing and the work he completed. I didn’t realize how much better the fireplace would look and function after the tuneup. His attention to detail and overall pride in his work was very evident and refreshing. Please continue to support great small businesses such as Grenz. Thank you Jim.read more

Scott

13:32 22 Jun 25

Hit all the marks. Sterling, Would highly... recommend!read more

Kirk F.

22:59 21 Jun 25

Very professional, knowledgeable, fast, and ... friendly. Highly recommended!read more

Pat H.

01:51 19 Jun 25

Grenz was responsive from my initial inquiry - ... they texted and called back immediately (it was after hours), they scheduled a 2-hour time window for the next day, showed up on time, and efficiently diagnosed and fixed our ac. They also did a nice job explaining the issues and what they suggested for repairs. Great job - I highly recommend them.read more

Renee B.

23:46 18 Jun 25

Everything was great! He was on time, worked... quickly and was very professional! Would definitely recommend!read more

Jessica L.

20:14 15 Jun 25

Always prompt & kind. Service and quality of work... are excellent.read more

Richard D.

14:54 13 Jun 25

We had five contractors provide quotes for a... complete furnace / AC / thermostat replacement. Pricewise, Grenz was squarely in the middle, even though they quoted a premium product. Jim walked us through the entire removal and instation process, including how and where they would relocate equipment, how to program the thermostat, and maintenance requirements. He made us extremely comfortable with both the equipment and their process. They arrived on time and cleaned-up thoroughly. Highly recommended.read more

Bonnie Blair C.

00:17 12 Jun 25

Grenz has been reliable for years and why we... still use them!!read more

Bradley L.

17:59 08 Jun 25

Grenz technicians did an excellent job of quickly... diagnosing the problem, installing the replacement capacitor and getting the AC back online in a jiffy. Have used Grenz for years and will continue to do so. I recommend Grenz to everyone I know.read more

Hartford, WI

Address: Hartford, Wisconsin, United States

Jefferson, WI

Address: Jefferson, Wisconsin, 53549, United States

New Berlin, WI

Address: New Berlin, Wisconsin, United States

Mukwanago, WI

Address: Mukwonago, Wisconsin, United States

Lake Mills, WI

Address: Lake Mills, Wisconsin, 53551, United States

Brookfield, WI

Address: Brookfield, Wisconsin, United States

Hartland, WI

Address: Hartland, Wisconsin, United States

Pewaukee, WI

Address: Pewaukee, Wisconsin, United States

Waukesha, WI

Address: Waukesha, Wisconsin, United States

Oconomowoc, WI

Address: Oconomowoc, Wisconsin, 53066, United States

Delafield, WI

Address: Delafield, Wisconsin, United States

Areas We Serve

PROVIDING SERVICE TO ALL of Delafield, WI and the surrounding areas

Delafield, WI

Address: Delafield, Wisconsin, United States

Oconomowoc, WI

Address: Oconomowoc, Wisconsin, 53066, United States

Waukesha, WI

Address: Waukesha, Wisconsin, United States

Pewaukee, WI

Address: Pewaukee, Wisconsin, United States

Hartland, WI

Address: Hartland, Wisconsin, United States

Brookfield, WI

Address: Brookfield, Wisconsin, United States

Lake Mills, WI

Address: Lake Mills, Wisconsin, 53551, United States

Mukwanago, WI

Address: Mukwonago, Wisconsin, United States

New Berlin, WI

Address: New Berlin, Wisconsin, United States

Jefferson, WI

Address: Jefferson, Wisconsin, 53549, United States

Hartford, WI

Address: Hartford, Wisconsin, United States

About

About Grenz Service Company LLC

Our Mission

What Sets Us Apart

Our Commitment

SEE WHAT YOUR NEIGHBORS ARE SAYING ABOUT Grenz Service Company LLC

Hartford, WI

Jefferson, WI

New Berlin, WI

Mukwanago, WI

Lake Mills, WI

Brookfield, WI

Hartland, WI

Pewaukee, WI

Waukesha, WI

Oconomowoc, WI

Delafield, WI

PROVIDING SERVICE TO ALL of Delafield, WI and the surrounding areas

Delafield, WI

Oconomowoc, WI

Waukesha, WI

Pewaukee, WI

Hartland, WI

Brookfield, WI

Lake Mills, WI

Mukwanago, WI

New Berlin, WI

Jefferson, WI

Hartford, WI

Free UV Light with the purchase of a new AC, furnace, or complete system

Free Diagnostic

Offer Disclosure