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TRUSTED BY COLESVILLE, MD HOMEOWNERS

  • Average homeowner rating star icon4.5
    Average homeowner rating
  • Verified reviews icon41
    Verified generator installs reviews

Find Generator install pros in Colesville

Long Electric, LLC
4.9(
167
)

Serving Colesville, 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."
Response time2 days
9 neighbors recently requested a quote
Recommended by91%of homeowners
Avatar for Nasr Electric Inc
Nasr Electric Inc
4.9(
276
)

Serving Colesville, MD and surrounding areas

Approved

In business since 2003

Free estimates

Warranties offered

"Joseph came to our home on 8 /28/21, to replace an outdoor GFI outlet. He was punctual, professional, and quite easy to work with. While he was there, I asked him to take a look at our very old electrical panel, and would he consider replacing it at a later date. He said, he needed to check his schedule and get back to me. He did. Joseph obtained the permit. We agreed on a date to install the new panel. I am very satisfied with the work performed by Joseph and his assistants. I'm sure it will pass inspection without issue. He's very good at what he does! Yes, I would hire again. Yes, I definitely would recommend."
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+19

Response time5 days
Response rate100%
1 neighbors recently requested a quote
Avatar for GAC Services
GAC Services
4.8(
291
)

Serving Colesville, MD and surrounding areas

Approved (Corporate)

In business since 1970

Free estimates

Warranties offered

"I’m back again to write another stellar review for GAC. Last year they replaced our HVAC system; this year we circled back and had them install a home generator. This was a long and drawn out process due to the various approvals needed from Montgomery County as well as coordination with Washington Gas (which ended up not just being a simple sign off but necessitating an additional, expensive upgrade to the gas line from the street to our home). Nevertheless, GAC did a fantastic job shepherding this process over the 6+ months of waiting on stakeholders, and they were also maximally accommodating to our family’s significant constraints on time and availability (due to health concerns related to a medically fragile family member). A special kudos to Sandy M, GAC’s master electrician, who took it on personally to ensure we were taken care of all throughout this process, going above and beyond with phone calls, text messages, personal visits, etc. on behalf of my family, I want to thank GAC and am giving top marks across the board for this effort which was complex , lengthy, and ultimately successful."
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66 neighbors recently requested a quote
Recommended by94%of homeowners
Avatar for William G Hyman Electrical Contractor
William G Hyman Electrical Contractor
4.8(
439
)

Serving Colesville, MD and surrounding areas

Approved

Super Service Award Winner

In business since 1980

Free estimates

Warranties offered

"Jeremy and his apprentice Kevin did an outstanding job. They were thorough, professional, polite, and explained the work being done throughout the job. Our house's electrical system was over 60 years old and not up to code or safe. Our fuse box was replaced with a new panel and breakers. The Pepco inspector remarked that Hyman's installation was one of the best installations that he has ever inspected. All of our outlets and switches were updated to meet code. The team found and resolved several problems that were serious safety issues. Our kitchen was upgraded so we could operate appliances without overloading the system. A line was installed to operate our air conditioner condensate pump directly and not from an extension cord. This was an expensive project and I know that I received the best service possible. I am very grateful to William Hyman Electrical for making our home safe."
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+6

Response time10 hrs
5 neighbors recently requested a quote
Recommended by96%of homeowners
Avatar for D&G Remodeling
D&G Remodeling
5.0(
38
)

Serving Colesville, MD and surrounding areas

Approved

Super Service Award Winner

In business since 2016

Free estimates

Warranties offered

"Deybi was super professional and he took the time to explain the electrical system in my old house and recommended the best option. He and his partner also took the time after the work was done to clean up after the work was done and made sure that I was satisfied with the final work. Would definitely hire again!"
Electrical Project
kitchen remodel
VIENNA KITCHEN REMODEL
FORT WASHIMGTON KITCHEN
ALEXANDRIA  BATHROOM RENOVATION

+50

Response time10 hrs
Response rate93%
4 neighbors recently requested a quote
Avatar for OC1 Electric
OC1 Electric
4.6(
51
)

Serving Colesville, MD and surrounding areas

Approved

In business since 2009

Customers say: Quick response

"Oupekkha showed up exactly on time, explained clearly what he was doing, what his annual service contract included and reassured me that our generator is good to go. He even topped off the oil for us. I signed up!"
Response time1 day
Recommended by97%of homeowners
JOHN MAX ELECTRIC
5.0(
22
)

Serving Colesville, MD and surrounding areas

Approved

Super Service Award Winner

In business since 2011

Free estimates

Emergency services offered

"The electrical team was professional, knowledgeable, prompt, personable and did an overall wonderful job. They are clearly expert electricians. They cleaned up after they finished the project. I would recommend them highly to my family and friends. As an added plus, they priced their work reasonably."
Electrical Project
Electrical Project
Electrical Project
Response time1 day
4 neighbors recently requested a quote
Recommended by95%of homeowners
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Generator Install questions, answered by experts

You can expect a diesel generator to last for up to 30,000 hours of use, which works out to 20 to 25 years with the proper maintenance, of course. That depends on how much you use it, so a diesel generator used for emergencies a couple of times a year will last a lot longer than a generator that takes over for a faulty electrical grid every month for a day or two. 

To power a central air system during a power outage, the whole-house generator will need to be at least 5,000 watts, and this number will significantly increase for larger units. Check the specific wattage requirements of your AC unit to choose the right generator size. Consider consulting a generator installer to ensure your whole-house generator meets your electrical load needs.

While the rating will tell you how many watts the refrigerator needs at the peak of its cycle, it requires additional wattage to start. At the bare minimum, you’ll need a 1,500-watt generator to get the fridge up and running after a blackout. A 2,000-watt generator should be sufficient for most home refrigerators.

Setting up utilities on a vacant property usually takes at least a few months, or between 6 weeks to 16 weeks. This process requires working with the local planning and zoning department, hiring a building contractor or engineer to design the utility layout, securing permits, laying the lines, and connecting the utilities.

To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.

Here are some typical wattage requirements for common appliances:

  • Refrigerator: 600 watts

  • Large dehumidifier: 700 watts

  • Large window air conditioner: 1,400 watts

  • Water heater: 3,000 to 4,500 watts

  • Electric furnace: 5,000 to 25,000 watts

A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.

While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:

  • 1,000 sq ft: 6–9 kW

  • 1,500 sq ft: 7–10 kW

  • 2,000 sq ft: 10–14 kW

  • 2,500 sq ft: 12–16 kW

  • 3,000 sq ft: 16–20 kW+

For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.

The Colesville, MD homeowners’ guide to generator installs

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