5 
23 *The Angi rating for Generator Install companies in Derwood, MD is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.
*The HomeAdvisor rating for Generator Install companies in Derwood, MD is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.
Last update on June 17, 2026
Serving Derwood, MD and surrounding areas
Approved
Super Service Award Winner
In business since 2007
Free estimates
Emergency services offered
"Outstanding! Super professional. Offered advice on my electrical installation and did the work quickly. I was very pleased with the end installation."
Serving Derwood, MD and surrounding areas
Approved
Super Service Award Winner
In business since 2010
Free estimates
Customers say: Quality work
"My experience is getting a new whole house generator installed by Long Electric was wonderful. They were responsive, timely and very professional. Everyone I dealt with was very courteous and answered all my questions over and over. I highly recommend their services."
Serving Derwood, MD and surrounding areas
Approved
In business since 2002
Free estimates
Emergency services offered
"The installation of my Ecobee thermostat was completed on Saturday by Stiffler Electric Service. David did a great job. I will certainly use Stiffler again."
Serving Derwood, MD and surrounding areas
Approved
In business since 2004
Free estimates
Credit card accepted
"Our existing generator died. James diagnosed the problem and gave us a few options to repair or replace it. We chose to replace it. James handled everything, from getting and installing the new generator to electrical and fuel (propane) connections. We have asked him to schedule us for the annual maintenance on the machine. We are pleased, though we haven't lost power since it was installed, LOL."
+6
Serving Derwood, MD and surrounding areas
Approved
In business since 2011
Free estimates
Emergency services offered
"Your technician that came out to do a yearly maintenance inspection on my generator was very nice and knowledgeable. He arrived actually earlier than expected and went right to work. I would recommend your company to anyone and it was so nice to deal with someone who acted like they enjoyed their work and wanted to please. Thank you!"
+8
Serving Derwood, MD and surrounding areas
Approved
In business since 2020
Free estimates
Credit card accepted
"Very friendly from the technician to the secretary. They got me in fast worked with my schedule and got out fast. They also mounted my ring doorbell.. Excellent service and the price was awesome"
+2
Serving Derwood, MD and surrounding areas
Approved
In business since 2014
Free estimates
Emergency services offered
"I had John and Aaron come to my home because I was interested in installing a Theater in my new home. They went through the new technologies and options for the Theater and were very knowledgeable. I ended up going with a 4K projector and a Dolby Atmos and absolutely love it and show it off to all my neighbors. Iâ m so glad I took their recommendation on spending the extra money on the projector to get true 4K. I watched the Pitt game this weekend in 4K and it was amazing. I totally recommend this company."
+26
Serving Derwood, MD and surrounding areas
Approved
In business since 1989
Free estimates
Emergency services offered
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.
Serving Derwood, MD and surrounding areas
Approved
In business since 2021
Free estimates
Credit card accepted
Calvert Generator is committed to excellence in every aspect of our business. 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.\n
Serving Derwood, MD and surrounding areas
In business since 2007
Free estimates
Credit card accepted
Electrical Service & Repairs - We guarantee your satisfaction, and we won?t leave until the job is done right. Our team has quality experience in this industry, and we make sure our customers are happy before we leave. Call or click to schedule an estimate today!
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