What is the lifespan of a whole-house generator?

<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>

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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 3 highly-rated local generator installers.

Verified Reviews for Generator Installation pros in Pelham, AL

*The Angi rating for Generator Installation companies in Pelham, 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 Pelham, 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 July 18, 2025

Reviewed in July 2015
Both employees were extremely professional and prompt. Very nice and polite. I could not ask for better service
Tidmore Inc
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Reviewed in October 2016
went very well happy with the service. The crew was very kind and professional on time and quick as if they have been doing this a long time. Clean up any mess that was made left our home looking the way it did when they came.
Tidmore Inc
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Reviewed in May 2012
I was very pleased. I felt like both men took time with me and never lost patience with all my questions. I would recommend them to anyone.
Guin Service LLC
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Reviewed in December 2012
I became a Sentry customer 3-years ago when they visited my home to give an estimate for a whole house generator. It included summer and winter maintenance for 2-years after it was installed. Not only did I purchase the generator, I also changed my yearly contract for heating and cooling...
Sentry Heating, Air, Plumbing & Generators
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Reviewed in June 2012
I pay $175 for the generator maintenance a year. I pay $150 to service my heating and air conditioning in the fall and spring respectively.
Capital Heating & Cooling
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Reviewed in February 2013
Earlier in the week, the standby generator had not operated properly during a power outage. Since the previous service company was not responsive, I called Sentry to inspect and service the unit based on their Angie's List reviews. I was pleasantly surprised when Sentry was able to send a...
Sentry Heating, Air, Plumbing & Generators
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Reviewed in August 2011
They were fine. They were great. They did a good job. We signed up for a year contract. It provides two servicing. They were very good, and that's about going right. I had some experience with some other companies, and Sentry charged $250, which was not a bad price. It includes more than...
Sentry Heating, Air, Plumbing & Generators
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Reviewed in January 2014
He was very professional. I had someone come in through the home warranty and they had absolutely no idea what they were doing. the house was freezing and no one knew how to fix it until capital came along. He found 2 leaks and at last the house is not freezing anymore
Capital Heating & Cooling
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Reviewed in April 2013
They put in our generator and do a yearly check. They came last year to do a service. I can't remember the exact date. They are wonderful. We personally met the owner. The same people always come out. They are due to service our generator soon.
Capital Heating & Cooling
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Reviewed in April 2013
I have a Generac generator that needed service after a couple of years of neglect on my part. Capital is a preferred service provider for Generac and I contacted them to schedule an appointment. The technician who arrived on time had 20 years experience with Generac generators and was very...
Capital Heating & Cooling
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