
Serving Glen Arm, MD and surrounding areas
Approved
In business since 2006
Free estimates
Emergency services offered
"Changed the brand of heat pump to be installed 24 hours before installation with no prior notice."





+5


Serving Glen Arm, MD and surrounding areas
Approved
In business since 2006
Free estimates
Emergency services offered
"Changed the brand of heat pump to be installed 24 hours before installation with no prior notice."





+5

Serving Glen Arm, MD and surrounding areas
Approved
In business since 2013
Free estimates
Warranties offered
"Genuinely honest, technically competent, and a penchant for pragmatic solutioning are the best ways I can describe Aaron and Blessed Cooling and Heating. They are at the top of our list for any future HVAC work."

Serving Glen Arm, MD and surrounding areas
Approved
Super Service Award Winner
In business since 1986
Emergency services offered
Warranties offered
"Nick Bull of Tim Kyle HVAC did an awesome job. Diagnosed the problem quickly, performed the service, explained everything clearly and all at a reasonable price. I entered into a service contract and scheduled mote maintenance work for next week. Highly recommend the Company in general and Nick specifically!"





+17

Serving Glen Arm, MD and surrounding areas
Approved
Super Service Award Winner
In business since 2000
Free estimates
Emergency services offered
"Relieved - that's how I would describe working with Carroll Mechanical. Ever since another company installed my furnace 6 years ago, I don't think it was ever working right. A number of companies have come over the years but nobody was able to properly diagnose the problem until Drew from Carroll Mechanical showed up. He was wonderful from the start and had over 50 years of experience in the trade. He spent the whole morning at my house running a full diagnostic, including a detailed combustion analysis plus measurement of gas pressures, duct air pressures, air temperatures, electrical readings etc.... he explained them all to me patiently like a good doctor and told me we what we needed to do - adjust supply gas pressures and increase the size of the exhaust flue to get the right air/fuel balance. Previous companies just wanted to get in and get out, but these guys took their jobs seriously and were just lovely to deal with. Insanely smart, caring, and reasonable people."



Serving Glen Arm, MD and surrounding areas
Approved
In business since 2004
Free estimates
Emergency services offered
"I received six estimates for replacing my air conditioning system. Of the six, four came in at a reasonable price including the estimate from the Michael Bonsby Company. Three of the four estimators made a good impression but the one who impressed me the most was David Lux of Michael Bonsby. He spent the most time, provided the most information, and fully answered all of my questions in all of my contacts with him prior to signing the contract. Even after I signed the contract, had the system installed, and made final payment, David Lux was still very prompt in answering my inquiries. So far I am very happy with the air conditioning system installed by and I would highly recommend the Michael Bonsby Company if you ever need to replace your air conditioning system."





+3

Serving Glen Arm, MD and surrounding areas
Approved
In business since 2013
Free estimates
Emergency services offered
"The company was a pleasure to work with. The quality and professionalism was good. The scheduling was quick and on time. I saw the previous complaints posted, but did not have any problems. I received their name thru Angies List and did not get additional estimates as it was 100 degrees and wanted AC ASAP. We told them that the fan wasn't working and needed repaired. They said the fan motor had a computer chip or some type of computer part with it and that's not common. After testing our AC unit their results showed that the condenser showed a good life span remaining. We were thinking about getting a new unit, they said it was our call but thought a repair would be a good choice. The boss called us and went over their findings and discussed our options. We decided to go with the repair due to the economy and their recommendation. When they removed the old motor they saw that it had been set to medium speed. Since I had previously told them our house is not balanced properly, he set it to high . The only thing I didn't care for was we had to pay for the estimate up front, but the fee was lower than I had expected. When we went to have it fixed they wanted the money up front again. I have always been taught to never do this but to put a deposit it down and pay in full when the job is complete. I did pay upfront again and did not have any problems. I do feel the fee was on the high side but again, I didn't get any other estimates and the other companies probably would have talked me into a new unit. We will see how long this unit lasts. The day after work was performed I had not received a receipt or warranty paperwork. I called the office and explained my thoughts of billing to them and they listened. Before I hung up my paperwork had been emailed to me. I would recommend them. They did not add any Freon and our unit is keeping our home cooler than ever. Thank you At Your Service."





+1

Serving Glen Arm, MD and surrounding areas
Approved (Corporate)
In business since 1945
Free estimates
Emergency services offered
"Arrived on time , very detailed on a very difficult install . The installation team checked all the boxes, I highly recommend this company for air-conditioning services."


Serving Glen Arm, MD and surrounding areas
Approved
Super Service Award Winner
In business since 2000
Free estimates
Warranties offered
Carroll Mechanical is an HVAC contractor that is dedicated to providing clients with the very best maintenance, repair, and installation services. We are based in Eldersburg and service customers throughout the MD region. We are a local business that is built on integrity, transparent pricing, and technical excellence. Our team of expert technicians have experience working with all major manufacturers. Our mission is to keep you comfortable and we proudly offer emergency availability where possible. If you are a homeowner, property manager, or business owner, give us a call today to learn more!



Serving Glen Arm, MD and surrounding areas
Approved
In business since 1989
Free estimates
Emergency services offered
"Fantastic company from start to finish! The gentleman who sold us the furnace, their salesman, Alex, was upfront in getting us the best price, along with a 10 yr parts and labor warranty included! The price for the furnace and installation was great, and they guaranteed apples to apples to meet any other companies cost. They offer a $100. fee if we found anyone to do it cheaper, with the same offer. They were able to schedule the intallation quickly, and did a great job intalling it. I would highly recommend using this company for your heating and air conditioning needs. Great company! Great prices! Great work! You won't be disappointed using Horizon Services! Take care....."





+27

Serving Glen Arm, MD and surrounding areas
Approved (Corporate)
In business since 1982
Free estimates
Emergency services offered
"The technician who serviced our furnace did an excellent job. He is knowledgeable, efficient, and courteous. We welcome him to attend to our heating and air conditioning needs at any time."

Most professional HVAC technicians require two to three hours to complete an expansion valve replacement. The timeframe depends on your unit's accessibility and whether additional repairs are needed. The process involves recovering refrigerant, removing the old valve, installing the new component, and recharging the system. Scheduling during less busy seasons may result in more convenient appointment times.
Operating your air conditioner with a malfunctioning expansion valve isn't advisable. Continuing to run the system could potentially damage other components, particularly your compressor, which is significantly more expensive to replace. If you notice performance issues like inconsistent cooling or unusual noises, it's best to have your system inspected before continuing regular use.
Expansion valves don't have a standard replacement schedule, as their longevity depends on system usage, maintenance frequency, and environmental factors. Regular professional maintenance helps identify potential valve issues before they cause system failure. Having your HVAC system serviced annually allows technicians to monitor component condition and recommend preventative replacements when necessary.
Refrigerant leaks require prompt professional attention. If your expansion valve is leaking, you'll likely notice reduced cooling performance and possibly hear hissing sounds near the unit. Addressing leaks quickly prevents further system inefficiency and avoids the environmental impact of released refrigerant. Your HVAC technician will need to repair the leak and recharge the system with the proper refrigerant type and amount.
Because many AC issues present similar symptoms, professional diagnosis is recommended. Problems like inadequate cooling, inconsistent temperatures, or strange noises could indicate expansion valve issues, but might also stem from refrigerant leaks, electrical problems, or airflow restrictions. A qualified HVAC technician has the tools and expertise to accurately identify the root cause and recommend appropriate repairs.
From average costs to expert advice, get all the answers you need to get your job done.

Use this guide to budget for appliance installation costs based on factors such as appliance type, installation complexity, labor rates, and more.

Explore how factors such as materials, local labor rates, and the type of damage affect the cost to repair a burst pipe.

Use this guide to learn how much rebar costs per foot so you can budget for your next big home improvement project.

Discover how factors such as linear footage, local labor rates, and trim type affect the total cost of painting baseboards.

Learn how much cat or dog door installation costs based on factors like the door size, material, location, and added features.

Discover how much an electric furnace costs based on factors such as unit size, local labor rates, electrical upgrades, and ductwork condition.