How long does a whole-house generator last?

<div>When maintained properly, a whole-house generator can last up to 20 years. <a href="https://www.angi.com/articles/how-much-does-generator-repair-cost.htm">Costs to maintain and repair generators</a> vary by location and type of generator, but you can expect to pay about $150 to $300 per year for annual generator maintenance checks. An experienced generator service technician will inspect your generator’s engine filter, starting mechanism, fuel, lubrication, and coolant levels to keep your generator in good working condition for as long as possible. </div>

How do I know what size generator I need?

<div>When <a href="https://www.angi.com/articles/what-size-generator-do-i-need.htm">choosing the right size generator</a> for your needs, consider a few items to help calculate the wattage you’ll need. Start by determining which household items and appliances you want to power, and then add the wattages together. Check out the wattage of these essential appliances:<ul><li>Refrigerator: 600 watts</li><li>Large dehumidifier: 700 watts</li><li>Large window air conditioner: 1,400 watts</li><li>Water heater: 3,000 watts</li></ul>Running home appliances like these requires a partial or whole-house generator. A portable generator may be enough to power your home if you only plan to keep a refrigerator and freezer running. </div>

What can I run on different generator sizes?

<div>Here’s what you can run with different wattages and types of generators:Portable generator:<ul><li>2,000 watts can handle a large appliance like a freezer or refrigerator, plus a few smaller items like phones or computer chargers. </li><li>4,000 watts will keep two large appliances operating and a few smaller devices.</li><li>8,000 watts should power most essential appliances and other devices, including a sump pump, well pump, or your dishwasher.</li></ul>Partial to whole-house generator:<ul><li>20,000 watts and above will make it seem like your home’s power is still on.</li></ul></div>

Get matched with top generator installers in Guntersville, AL

Q: How much does a whole-house generator cost?

<div><a href="https://www.angi.com/articles/how-much-does-it-cost-install-generator.htm">Installing a whole-house generator costs</a> about $5,000 on average. Prices range from $1,550 to $8,500, depending on size, brand, fuel type, and assembly. The size of your whole-house generator is the most significant cost factor, with large homes with high energy demands costing the most to power. Types of whole-home generators include:<ul><li>Portable generators with 1kW&ndash;7.5kW capacity: $500&ndash;$2,000</li><li>Partial generators with 9kW&ndash;20kW capacity: $2,000&ndash;$6,300</li><li>Whole-house generators with 22kW&ndash;48kW: $5,000&ndash;$18,000</li></ul></div>

Q: What can I run on different generator sizes?

<div>Here&rsquo;s what you can run with different wattages and types of generators:Portable generator:<ul><li>2,000 watts can handle a large appliance like a freezer or refrigerator, plus a few smaller items like phones or computer chargers. </li><li>4,000 watts will keep two large appliances operating and a few smaller devices.</li><li>8,000 watts should power most essential appliances and other devices, including a sump pump, well pump, or your dishwasher.</li></ul>Partial to whole-house generator:<ul><li>20,000 watts and above will make it seem like your home&rsquo;s power is still on.</li></ul></div>

There are 4 highly-rated local generator installers.

Matching on Angi

Share some details about your home project.

Within moments, match with highly-rated local pros.

Compare quotes and choose the best pro for the job.

Verified Reviews for Generator Installation pros in Guntersville, AL

*The Angi rating for Generator Installation companies in Guntersville, AL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Installation needs.

*The HomeAdvisor rating for Generator Installation companies in Guntersville, AL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Installation needs.

Last update on April 09, 2025

Reviewed in September 2012
They called before coming out and were here when they said they would be. They were very responsive to our concerns and did all the was requested of them. They didn't leave a mess, they hauled away all the items that they had replaced. They had to come back several times because of a...
Mister Sparky Huntsville
Request a quote
Reviewed in September 2012
Adam has done several jobs at my house. I did not know until I called that they would service (provide preventive maintenance) on my generator. I had already purchased all the parts and the oil and then had second thoughts about my ability to perform the work in a competent manner. Adam...
Mister Sparky Huntsville
Request a quote
Reviewed in June 2015
They were excellent. I think they came twice. I think around January. It was done in a reasonable time for a couple of hours. I thought i would have him all day. I think he just knew what to do. He totally knew his stuff. He was very pleasant. I feel like they know what they are doing and I...
Mr. Electric of Huntsville
Request a quote
Reviewed in April 2016
Two technicians, Trent and Jordan, arrived on time. They were very professional and did a quality job took time to answer all of my questions. Demonstrated the unit.
Tidmore Inc
Request a quote
Reviewed in May 2014
They were to arrive at 1:00 pm and arrived 10 minutes early, calling to let me know they were on they way. They were very courteous, professional and they took all the boxes, inserts and old light fixtures and discarded them for me. I will be calling Steve with Current Electrical...
Tidmore Inc
Request a quote
Reviewed in August 2014
Current electrical Services arrived on time. They completed the work in a very professional manner. All work was neat and they cleaned up after themselves.
Tidmore Inc
Request a quote
Reviewed in June 2014
Purchased generator from Home Depot and Mr Electric is their installer. The install was without major incident and took over a week to complete because of the number of parties involved (plummer, city inspectors and Huntsville Utilities.) All parties involved were professional and did a...
Mr. Electric of Huntsville
Request a quote
Reviewed in June 2014
They are excellent, they came to the house, very professional. I ended up buying the generator. He was thorough, his price was comparable to the one i used. I wished i could have used him to be honest they were nice.
Tidmore Inc
Request a quote
Reviewed in July 2013
All the personal were polite and responded to any question that I had. They always came at the appointed tie and finished the installation, at the agreed price. I would hire Current Electrical, for any electrical need I might have, in the future.
Tidmore Inc
Request a quote
Reviewed in September 2016
Work went as scheduled. Personnel were very professional and cleaned up behind themselves. Generator functions perfectly and is much quieter than the older model (non-Generac). Answered all my questions about the new generator and took their time to complete the job. A true turn-key install.
Tidmore Inc
Request a quote