Horizon Services (MD), LLC, is the regions largest and most well respected plumbing, heating and air conditioning company, with nearly 600 employees serving tens of thousands of homeowners throughout Delaware, Southeastern Pennsylvania, Southern New Jersey and Northeastern Maryland. After a quarter of a century in business, Horizon Services (MD), LLC, remains fully committed to setting the industry standard for customer service, installation and focusing on things that are important to busy homeowners.
"Good job"
maribel c on March 2025
Horizon Services (MD), LLC, is the regions largest and most well respected plumbing, heating and air conditioning company, with nearly 600 employees serving tens of thousands of homeowners throughout Delaware, Southeastern Pennsylvania, Southern New Jersey and Northeastern Maryland. After a quarter of a century in business, Horizon Services (MD), LLC, remains fully committed to setting the industry standard for customer service, installation and focusing on things that are important to busy homeowners.
"Good job"
maribel c on March 2025
Welcome to Markool Heating & Cooling. We proudly provide the highest quality of service and craftsmanship for each aspect of your project. Our depth of knowledge and experience solidify our belief that customer service stands as the highest priority. We eagerly look forward to working with you and making your vision a reality. Give us a call, text, or email today, and let us get started!
"Woke up this morning to my hvac leaking and contacted Markool. I have never used them before and was in a pinch. They fit me right in this morning and were out at my house within 2 hours. The tech stepped in the door and placed covers for his shoes so he did not track in any dirt which was impressive! The tech was very professional and super friendly. Problem was diagnosed and FIXED within an hour. The price was extremely reasonable to the point I was shocked in a good way (expecting a higher price). Anyways, I will most certainly be a returning customer. Thank you Markool Heating Cooling Plumbing."
Chase R on August 2024
Welcome to Markool Heating & Cooling. We proudly provide the highest quality of service and craftsmanship for each aspect of your project. Our depth of knowledge and experience solidify our belief that customer service stands as the highest priority. We eagerly look forward to working with you and making your vision a reality. Give us a call, text, or email today, and let us get started!
"Woke up this morning to my hvac leaking and contacted Markool. I have never used them before and was in a pinch. They fit me right in this morning and were out at my house within 2 hours. The tech stepped in the door and placed covers for his shoes so he did not track in any dirt which was impressive! The tech was very professional and super friendly. Problem was diagnosed and FIXED within an hour. The price was extremely reasonable to the point I was shocked in a good way (expecting a higher price). Anyways, I will most certainly be a returning customer. Thank you Markool Heating Cooling Plumbing."
Chase R on August 2024
It is our mission, to provide excellent workmanship and complete customer satisfaction, from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety and quality, regardless of how large or small the job.
"They took the time to diagnose the issue and then clearly explained what was going on."
Richard I on January 2025
It is our mission, to provide excellent workmanship and complete customer satisfaction, from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety and quality, regardless of how large or small the job.
"They took the time to diagnose the issue and then clearly explained what was going on."
Richard I on January 2025
Comfort First Heating & Cooling is the team you need for all your home solutions. Comprehensive comfort is our legacy. We're dedicated to delivering unparalleled customer service that mirrors our core values of integrity, stewardship, and excellence. We look forward to having you join the Comfort First family as we continue our mission of creating customers for life by earning your business.
Comfort First Heating & Cooling is the team you need for all your home solutions. Comprehensive comfort is our legacy. We're dedicated to delivering unparalleled customer service that mirrors our core values of integrity, stewardship, and excellence. We look forward to having you join the Comfort First family as we continue our mission of creating customers for life by earning your business.
We guarantee your satisfaction, and we won’t leave until the job is done right. We pride ourselves on the quality work we provide, while delivering great customer service! Check out all the services we offer below and call -or- click to schedule an estimate today!
"Arrived on time, professional, got the job done quickly and provided clear explanations on what was required for the job. Would recommend their services and signed up their membership plan to maintain my system to prolonged life span."
Meifeng L on May 2023
We guarantee your satisfaction, and we won’t leave until the job is done right. We pride ourselves on the quality work we provide, while delivering great customer service! Check out all the services we offer below and call -or- click to schedule an estimate today!
"Arrived on time, professional, got the job done quickly and provided clear explanations on what was required for the job. Would recommend their services and signed up their membership plan to maintain my system to prolonged life span."
Meifeng L on May 2023
GAC Services is a residential cooling, heating, and electrical contractor setting new standards in the Maryland HVAC and electric market. Since 1970, we’ve developed a strong reputation for providing the Montgomery County and Frederick County areas with reliable cooling and heating services. In 2014, we expanded our service offerings to include electrical services—allowing us to offer our customers the same great service in a new area of business. Additional DBA: Gaithersburg Heating & Cooling
"Highly professional, knowledgeable and well behaved technician. Prices offered were good too. I definitely recommend the company."
Deepak K on February 2025
GAC Services is a residential cooling, heating, and electrical contractor setting new standards in the Maryland HVAC and electric market. Since 1970, we’ve developed a strong reputation for providing the Montgomery County and Frederick County areas with reliable cooling and heating services. In 2014, we expanded our service offerings to include electrical services—allowing us to offer our customers the same great service in a new area of business. Additional DBA: Gaithersburg Heating & Cooling
"Highly professional, knowledgeable and well behaved technician. Prices offered were good too. I definitely recommend the company."
Deepak K on February 2025
In Business Since 2023 CDCP Repairs is committed to excellence in every aspect of our business. CDCP has over 30 years of experience in the industry. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business How We Got Started I chose to work in this industry because I grew up working along side my father and understanding the hard work and skill and dedication it takes to get these projects done efficiently and quick. I’ve now had his business handed down to me and am now on both sides of the hard work and the business side of things.. We started in this industry in 2023. We describe our business as Family owned and operated
"Super happy with both times we have hired Tim for painting services."
Anne p on January 2025
In Business Since 2023 CDCP Repairs is committed to excellence in every aspect of our business. CDCP has over 30 years of experience in the industry. We uphold a standard of integrity bound by fairness, honesty, and personal responsibility. Our distinction is the quality of service we bring to our customers. Accurate knowledge of our trade combined with ability is what makes us true professionals. Above all, we are watchful of our customers' interests, and make their concerns the basis of our business How We Got Started I chose to work in this industry because I grew up working along side my father and understanding the hard work and skill and dedication it takes to get these projects done efficiently and quick. I’ve now had his business handed down to me and am now on both sides of the hard work and the business side of things.. We started in this industry in 2023. We describe our business as Family owned and operated
"Super happy with both times we have hired Tim for painting services."
Anne p on January 2025
Holtzople is a leading HVAC company in Frederick, Carroll, and Washington counties in Maryland, as well as Adams and small parts of Franklin & York counties in Pennsylvania, featuring all the top brands in the Heating and Cooling industry, such as Trane, Bryant, Lennox, Carrier, ClimateMaster, WaterFurnace, and more. We recently added an electrical department to our services, making us your one-stop shop for HVAC and electrical needs. Quality is Not Expensive, It's Priceless!
"From Josh Radford our comfort consultant to our install crew of Shane, Jake and JT everything was top notch!"
Vickie S on April 2025
Holtzople is a leading HVAC company in Frederick, Carroll, and Washington counties in Maryland, as well as Adams and small parts of Franklin & York counties in Pennsylvania, featuring all the top brands in the Heating and Cooling industry, such as Trane, Bryant, Lennox, Carrier, ClimateMaster, WaterFurnace, and more. We recently added an electrical department to our services, making us your one-stop shop for HVAC and electrical needs. Quality is Not Expensive, It's Priceless!
"From Josh Radford our comfort consultant to our install crew of Shane, Jake and JT everything was top notch!"
Vickie S on April 2025
Our mission is to be a provider that brings back the personal touch with our customers. We will build a relationship that will last a lifetime after you see our quality work. As a locally owned and operated business we feel invested in our clients and constantly strive for customer satisfaction. Call or message us to schedule an estimate today!
"Dennys and his team replaced our front door and accompanying trim/frame, storm door, painted a shutter, and completed some additional tasks not requested initially. The quality of work was excellent across the board. Dennys' expertise in these project areas was clear not only by the quality of work but also by his clarifying questions and thoughtful suggestions on how certain approaches might work better than others. Working with Dennys was a pleasure. He was professional, polite, courteous, and very responsive. We were extremely pleased with the outcome of the projects, would recommend him to others, and look forward to him doing more work for us."
August B on November 2024
Our mission is to be a provider that brings back the personal touch with our customers. We will build a relationship that will last a lifetime after you see our quality work. As a locally owned and operated business we feel invested in our clients and constantly strive for customer satisfaction. Call or message us to schedule an estimate today!
"Dennys and his team replaced our front door and accompanying trim/frame, storm door, painted a shutter, and completed some additional tasks not requested initially. The quality of work was excellent across the board. Dennys' expertise in these project areas was clear not only by the quality of work but also by his clarifying questions and thoughtful suggestions on how certain approaches might work better than others. Working with Dennys was a pleasure. He was professional, polite, courteous, and very responsive. We were extremely pleased with the outcome of the projects, would recommend him to others, and look forward to him doing more work for us."
August B on November 2024
Whether you need a repair, preventive maintenance, or replacement, we are your plumbing, heating, and air conditioning service provider in the northern Virginia and surrounding areas. We invite you to give us a call!
"Nice, reliable, and responded immediately."
Ethan Q on January 2025
Whether you need a repair, preventive maintenance, or replacement, we are your plumbing, heating, and air conditioning service provider in the northern Virginia and surrounding areas. We invite you to give us a call!
"Nice, reliable, and responded immediately."
Ethan Q on January 2025
Coils work to absorb heat into the refrigerant that flows through them, moving heat from one location to another. For air conditioning, the evaporator coil inside the air handler in your home absorbs heat. It then transfers the heat outside to the condenser coil, where it releases it. The opposite process happens for heat pumps. When the coils get dusty and dirty, it reduces how well these components work.
Skip regular cleanings, and dirt, debris, and mineral deposits will blanket your evaporator and condenser coils. When that happens, the coils can’t shed heat efficiently, so the system works harder and your energy bill climbs. Over time, overheating strains the compressor and can trigger a full breakdown—an avoidable repair that often costs far more than a simple annual cleaning.
AC coil cleaning is an investment that pays for itself in the benefits it provides. Dust‑caked coils force your AC to run longer, so you spend more on electricity and rack up extra wear. A quick professional cleaning restores efficiency, trims monthly bills, and eases strain on expensive parts. Over the long haul, that small yearly fee delays pricy repairs and stretches the unit’s lifespan, making coil cleaning one of the smartest HVAC tune‑ups you can schedule.
Watch for higher electric bills, rooms that stay warm no matter how low you set the thermostat, or an AC system that runs nonstop. Extra humidity and frost on the coils are also red flags. Catching these clues early lets you schedule a quick cleaning before the system overworks itself and triggers an expensive breakdown.
Your AC cleaning technician starts by shutting off the power to the unit and removing the faceplate. Compressed air and a vacuum hose blast away loose debris, followed by a coil-safe, no-rinse cleaner that dissolves stubborn grime. After the solution has soaked in, the professional wipes the fins, reassembles the housing, and restores power, leaving the system ready to cool at peak efficiency.