All reviews for Donmar Heating, Cooling & Plumbing

Very pleased with our new hybrid system from Donmar. Excellent customer service. Best price among four quotes from local competitors. Expert installers answered our questions thoroughly and walked us through thermostat setup. Feel we're in good hands.

Very pleased to have selected Donmar as my new Heating & Cooling service provider. Everyone I've dealt with at the company has been extremely professional and helpful - from the office folks to the technicians. They provided clear communication throughout every step, showed up when they said they would, and have my new AC system ready for the summer. Special thanks to Javier, Carlos, and Ricardo.

Donmar sent Sean to troubleshoot our heat on a cold morning. He was able to get it fixed in no time and provided us with a quote for replacement since the unit was 30 years old. He took his time and answered all of my questions. No pressure sales discussion, extremely professional, courteous, and honest. The owner, Don, was extremely patient with all of my questions while I was attempting to find the best equipment and deal between 2 competitors. Don’s patience, honesty, and knowledge won me over despite paying a little more money. That extra money was well worth it when Edgar showed up to install. He was the most competent, kind, and patient contractor I have ever had in a home. I cannot compliment him and his assistant enough on the meticulous craftsmanship exhibited during the installation of a new Carrier furnace and AC unit. He took his time to make sure everything was right and we understood how to use the new system.

I would only recommend Donmar for either a HVAC repair or system replacement. Donmar is a prime example of how service companies should be. I would give them 10 stars if I could!!! Thanks again Sean, Don, and Edgar!!!!!!

Hired Donmar to do a full HVAC and water heater replacement. They were from a trusted reference and were by far the cheapest of the three quotes we received while at the same time delivering the highest quality equipment options. Installation was efficient and without any issues and the communication was top notch. When I had the country inspectors out to look at the work, both commented that they’re not used to seeing that level of workmanship and commended the installers on their work. Will definitely go with Donmar in the future for any plumbing/HVAC needs.

I had a fantastic experience with this company and want to give a special shoutout to technician Brian G. He was extremely professional, respectful, and well spoken throughout the entire process. He took the time to answer all of my questions and made sure I felt comfortable with the work being done. Brian treated both my property and myself with great care, leaving the garage area spotless and taking everything with him when he left. It’s rare to come across this level of service and professionalism, highly recommend this company to everyone!
One thing that really stood out was when I mentioned I didn’t like the appearance of a plate behind the thermostat, Brian took a few extra minutes to remove it, without hesitation or frustration, and handled it with a smile on his face. That kind of attitude and attention to detail is rare these days.

I had to replace my Carrier Infinity HVAC system from 2008. I got 3 bids and Donmar's estimate was the best price. But even more important to me was that Michael W., the sales representative gave me the best service by answered all my questions in his visit and through email. He explained the process, told me why he was recommending a particular option and provided information about the rebate and tax credit. The proposal contained all the information I needed to make an informed decision.

The installation was scheduled for the next week. I was sent the picture of the foreman (Edgar) and a link to be able to track his arrival time. The crew was polite, very careful with my home, and cleaned up each day. It was fast, efficient and painless.

Edgar was very patient and tolerant teaching me how to use the system, providing all the documentation for the tax credit as well as including photos of all the installed equipment, and scheduling the county inspection. He told me to call if there were any questions or issues.

It was one of the most effective installations I have ever experiences and I have build two houses. I was very pleased and will definitely call them when I have to replace the other HVAC system or my water heater.

Amazing company! Sales (Michael) and crew (Carlos and team) were so nice and professional. Carlos is a true asset! They customized our job to our unique needs, and the pricing was super competitive! I would highly recommend. We are a customer for life!

Donmar company is the best HVAC service provider I’ve encountered in many decades of homeownership. They offer fair pricing, demonstrate true professionalism, and treat your home with the same care and respect as if it were their own.

Manuel and Edgar our two technicians have been outstanding! They have gone above and beyond what could be expected, working during the peak of heat wave to install my two new systems. Always very polite, providing timely updates and completing the work on schedule. They have been simply fantastic!!

As a maintenance coordinator for a property management company, I have used many HVAC contractors. No one compares to Donmar. Always professional and on time. The techs are very knowledgeable and great at communicating with the tenants and us. The office personal is top notch. Don will call me personally to discuss any tricky situations. Donmar estimates are always competitive. Usually they are better than the rest. It has been a privilege to work with them over the years and I look forward to working with them far into the future.
Do yourself a favor and call them. You will not be disappointed.

Easy to make appointment and the service technician is very professional and inspect my unit very carefully. I pay $178 for a contact to have them to come checking my unit twice a year. I am glad to have Donmar Heating, Cooling to take care my HVAC system. I have renewed my contract again today.

I had a great experience with Donmar to replace my entire HVAC system. Michael was very responsive and professional and the crew came out to save us from the crazy heat wave we are currently experiencing in Maryland. Good price and customer service, helping me do some impromptu landscaping to fit the new units. Highly recommend!

Chris was very diligent and clearly knew what he was doing. He did his very best to restore the operation of our furnace.

Donmar is reliable and honest. Technician (Chris) arrived exactly on time. He was very courteous, cordial, and informative. In addition to explaining the specific service he was tasked to perform, he provided useful information about the operation of our system. We will use Donmar again for our home heating/AC system needs.

Mayer did a great job of replacing our air scrubber UV cell this morning. He arrived on time and was very professional.

HVAC purchase and installation.
Technicians Manuel and Edgardo, installed my new HVAC on 4 Sept 2026. They were very thorough and patient with the process as issues arose with installing it due to my Condos’ HOA poor management skills of the property, including scheduling. Once the project got started, they were quick and even taught me how to set-up my thermostat. They also taught a thing or two to my PM’s Tech. Excellent Service!

Jude

I had the pleasure of working with Donmar Heating and Cooling for the installation of a new air conditioning and furnace system, and the experience was truly exceptional. In an era where genuine professionalism and high standards are becoming harder to find, this team delivered on every front.

The installer was punctual, courteous, and meticulous—clearly taking pride in their work and ensuring everything was done right the first time. Just as impressive was the salesperson, who was always accessible and quick to respond to any questions or concerns I had. Their clear communication and support made the entire process smooth and stress-free.

Although I won’t need to be a repeat customer for this type of installation, I can say with full confidence that Donmar Heating and Cooling is a highly trustworthy organization that I would recommend without hesitation. Their commitment to excellence and competitive pricing is a rare and refreshing combination in today’s market.

I had a fantastic experience with Donmar Heating, Cooling & Plumbing in Sterling!
My A/C had stopped cooling, and it turned out I needed both a compressor replacement and a freon recharge. The team was professional from start to finish—arrived on time, quickly diagnosed the issue, and explained everything clearly.
They didn’t try to upsell or overcharge—just straightforward, honest service. The compressor was replaced efficiently, and once they recharged the system with freon, my home was back to being cool and comfortable in no time.
Highly recommend Donmar for anyone needing reliable HVAC service. These guys know their stuff and truly care about their customers!

Great family company!

We have used Donmar to replace two HVAC units and also our water heater. Our family have been using Donmar for years and have always had exceptional service. From the front desk to the service providers, they have all been extremely professional and done an excellent job with the work. We previous had tried three other companies when we were having issues with our AC and Donmar was finally the ones who could identify the problem.

The team at Donmar has always been outstanding to work with. Very knowledgeable and communicates extremely well about what ever they are doing.

I contacted Donmar for an estimate to replace my Outdoor AC unit and the hot water heater tank. The estimate I received was very reasonable, so I decided to go with them.
Edgar came on the install day on time and explained in details what they will be working on. Edgar is extremely knowledgeable and answered all my questions prior to do the install.
I’m very impressed with the professionalism Donmar team displayed during this entire process. Definitely will be going back to them for all my future HVAC needs.