We appreciate the feedback our customers have given us.  If you would like to post a review of Radiant Design & Supply on Google, our Houzz.com profile, or send us an email for this page, we are happy to have your comments and, with your permission, will add them to this page.  Radiant Engineering's new name as of June, 2017, is Radiant Design & Supply, Inc. Thank you!

A happy ThermoFin customer writes, "To install the plates square to the joists and 8" OC, I made these wooden blocks.  Turns out the width of a 2x4 is just about the right offset from the edge of the joist to the edge of the plate. The two strips of 1x3 are attached to a 6" length of 2x4, just a little bit below the edge.  They provide a lip to support the plate. I just clip two of these blocks to the joist using vice-grip welding clamps, then I can slip the plate into the ridge and slide it back and forth to where I want it.  Using this technique I can put the plates up very quickly without needing an assistant."

ThermoFin C radiant heat transfer plates review and testimonial.

Terry Davenport goes on to say, "My system runs at 110 f and returns at 100 f.  It is a 440 ft2 cottage with 3, 150 ft loops one zone, electric boiler.  The hardwood pex is in between 3/4", 8" plywood.  The bath tile floor is the same only with the heat transfer plates on the top of the 3/4" plywood, then 3/8" hardy tile underlayment, then tile.  The floor is insulated between the joists with R21 fiberglass. The cottage has a very low heat loss.  The walls are R of 40. The roof is R 90."

A happy Viessmann customer sent us a couple of photos of his mechanical room with this comment: "Sittin in the closet, purrin like a kitten!!"

Viessmann Vitodens mechanical room by Radiant Engineering

Viessmann Vitodens mechanical room by Radiant Engineering

Viessmann Vitodens mechanical room by Radiant Engineering

Viessmann Vitodens mechanical room by Radiant Engineering

Scott earned our business from this point forward, he repaired a pilot light issue we have had in our home for nearly a year, and that no other local service technicians could identify and repair adequately. In my opinion Scott is worth the extra expense of using an out of town service technician for boiler and Tekmar control system service.

Please feel free to use this communication as a testimonial of your company's prompt attention to my service needs and Scott's high level of understanding of our home's complex in-floor radiant heat design.

Best Regards,

Owner of a home in Helena.

Testimonial review Radiant Engineering Inc

Thank you your customer service is outstanding!
E. S., Connecticut


Scott did a great job! Thanks for the terrific service!
Mark, Montana Ale Works


Thanks for your friendly service. No problems or questions. Happy New Year!
Manhattan, MT

Radiant Engineering did the job that no one else wanted to do. They installed hot water heat in a house without an attic or basement and did a perfect job. They are available when we have a question and are always helpful and friendly. The heat works as promised and it is wonderful to have a warm house. We highly recommend Radiant Engineering.

Regina Seagrave


I went with a new plate called ThermoFin from Radiant Engineering from here in Montana. I drove over to them on Wednesday night and purchased enough plates to do the entire house. The plate mounts upside down from what you see here. The plate is fastened first to the underside of the floor, then the tubing is hammered into place. I LOVE these plates so far. They are a joy to work with.

Radiant Engineering said many installers use staples to staple the plates in place (their web site has instructions which says to use screws). I tried the staples. Only about 1 in 3 would make it through the plates. The plates are 0.062 inches thick. This might not seem like much but these are about 4 times thicker than the other aluminum plates. This extra mass allows the water temperature for the radiant floor heat to be lower (which will save energy in the long run).

What was up, is now down. I tore down all of the cheap aluminum plates I had put up last week. The majority of them I never used so I will be shipping them back to get my money back on them. I guess I'll see if a local recycling place will give me anything for these.

ThermoFin heat transfer plates testimonial review for Radiant Engineering Inc


DIY Homeowner


Our customers have a sense of humor. Above is an envelope we received with a "thank you" and this sticker on the back.


I have been in the radiant heat supplying business since 1984 and have used many different heat transfer plates. Here at AVCO Supply, we ONLY stock the ThermoFin product, the best aluminum heat transfer plate.In the past six months we have purchased over 5 tons of ThermoFins. Our orders have always arrived on or before the due date and the new packaging is GREAT.The plates are of high quality, and perform beyond Radiant Engineering’s claims. Our contractor customers are pleased as the heat transfer is almost the same as gypsum, the plates make no noise, and installation time is cut in half compared to tin plates. These plates guarantee satisfaction for everyone involved with NO CALL BACKS! A great product!

Steve Wieland

AVCO Supply

Levitown, Pennsylvania

With the two profiles, CFin and UFin, I am able to offer more options to my clients. ThermoFin enables high performance radiant retro-fits, and I believe it is the only way to do radiant hardwood floors.

Dave Haggart

Radiant Floor Heat Specialties

Great Falls, Montana

In radiant heating we want the highest and quickest heat transfer possible. That’s why we use only ThermoFin extruded aluminum plates. They are heavier and fit a lot tighter than the competitor’s plates; well worth a few extra pennies.

Troy Morgan

Radiant Floor Heating Company

Hamburg, New York


Having installed in excess of three miles of both Ufin and Cfin*, I can attest to the phenomenal performance of these heat transfer plates. They outperform gypsum based underlayments and all other suspended construction radiant when it comes to heat output and low water temperatures. Whether new construction or retrofit work, ThermoFin plates are the winner, hands down.

Jeffrey Young

Climatec Advanced Heating Technologies

Easton, Pennsylvania

*ThermoFin U and ThermoFin C


We’ve used the ThermoFin product on a number of projects and our clients are quite happy and comfortable. We are very impressed with the performance of the product and the versatility it lends to our system designs.

Michael G. Ward

E & W Heating and Air Conditioning, Inc.

Middleton, Wisconsin


We have been using Radiant Engineering’s Thermofin for over three years now. Numerous projects have proven that these thick extruded plates are ideal for retrofitting radiant heat.The guys in the front office are always available for questions and their engineering guidelines are easy to use. Highly recommended.

Alan Forbes

Forbes Plumbing

Oakland, California


ThermoFin is the original extruded aluminum heat transfer plate and still the best. When it comes to heat transfer, the gauge, fit, tolerance, consistency, and quality of the extrusion are what you are paying for. Having tried all the brands currently on the market, in my experience, the ThermoFin is the hands down leader. The performance and output testing is head and shoulders above the competition.

Bob (HotRod) Rohr

Rogersville, Missouri


I wanted to use radiant heat in a wood floor assembly over an unheated basement. The process Radiant Engineering described involved the use of heat distributing aluminum fin that comes in standard lengths and simply clips over the plastic heating tubes and acts as a built-in floor radiator to distribute the heat. We found the installation process to be very straightforward. Now that we have lived with our radiant heating system for over five years with minimal maintenance, we are completely sold on its comfort, silence, and durability.

Bob Bayley, Architect, AIA

Ennis, Montana


Radiant helped me through the whole process and for 7 years have been there for me – think support, support, and more support.

Tam Halling


I feel Radiant Engineering has been very helpful any time I have needed help with trouble shooting or installation or design. We have had great success with the Aluminum transfer plates. They work very well in certain situations.

Mike McLean

McLean Plumbing and Heating


We found that the Radiant Engineering staff was very knowledgeable about radiant heat designs. In all contacts (phone, in person), they were helpful to us and answered all our questions.

Bruce W. Mazuranich


It would be no problem for me to grade Radiant Engineering an “A” in all categories of business practice in regard to customer care, knowledge, and expertise.

Eric D. Schuller


Dear Radiant Engineering,

Thank you so very much for your swift response to the boiler break-down in West.  I really appreciated all your help over the phone on that day, & for all the work you accomplished.

Thanks so much,

Bruce Visser



Just a note to let you know how happy we are with the Viessmann boiler.

The unit is so quiet we barely can tell it is on, and the temperature in the house stays even, not like our old unit. 

When we called, Randy and Pat were at our house within a day.  They took several pictures of the furnace location.  They send [sic] us a detailed quote containing each part, along with the approximate labor time.

Randy did the installation at a little less than the quotes time, so our bill was less than quoted.  Randy did a wonderful job on installing the unit.  He is a real professional.

We had requested quotes from five companies.  Some quotes were higher than yours and some were lower, but no one sent a detailed quote of what they were going to do.  Believe it or not, we just received the last quote five weeks late.

It’s nice to work with an organized, professional company.  If any of your future customers want to call us, we would be glad to talk with them.

Thank you,

Barry and Merry Hukill


We wanted the best floor heating systems available for the Main House and Bunkhouse (guest house).  Both were installed by RADIANT – very excellent workmanship.  Any work or “modifications” and repairs have been followed up quickly by the service department… great service is very important too!


F. Craig Barber

2 Bar B


Dear Mr. Pickard:

I am writing to express my pleasure with one of your employees.  We recently built a house in Ennis, Montana and looking back on this process, we want you to know that working with Pat Reardon was one of the true highlights of that experience.

Pat was the most knowledgeable [sic] person – I say again, the most knowledgeable person -  at Radiant Engineering who helped us.  Until we met him, we were not sure we wanted to install your product.  He clearly understood your company’s system and installation procedures; he knew what he was talking about and if he ran into something he didn’t know, then he found the answer and told us later.  He was constantly professional, pleasant and agreeable.

With Pat’s directions, we installed the fin and tubing ourselves.  In January 2006, at 10 degrees below zero, it was a difficult job and not one I’d do again.  But it was made easier because we knew that with Pat’s instructions we’d do it right the first time.

Two days after the boiler was installed, it wouldn’t light.  I called Pat at home and he was in our basement the next day and the day after too, working at 20 degrees below zero until he identified the problem and got the boiler running again.

I hope you know that this guy Reardon is a very valuable asset to your company.  I hope you know what a quality employee he is and treat him accordingly.


Bill Carpenter


Customer Service:

RE has been helpful in answering questions and troubleshooting systems.  Their first hand experience installing and maintaining the equipment they sell is a bonus not found in most distributors.  I have found technical help to be better than offered by the manufacturer in some cases.

I have been frustrated at times on the turnaround times for some quotes.I realize staffing changes are not always planned, and with some experience now I can do a little better figuring on my own so it isn’t as much of a problem.

Engineering Expertise:

I trust R.E. to design a system that is adequate and efficient. From looking at systems that others have designed, I find many times they either seem to be overdesigned in the size and amount of equipment or that too many shortcuts have been taken just to reduce cost.

Product Quality:

I have found that the products that RE sells to be some of the best in the industry. On the few occasions that parts have failed they have been very helpful to get them fixed or replaced.

Glen Kauffman

Montana Radiant, LLC