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>

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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 19 highly-rated local generator installers.

Verified Reviews for Generator Installation pros in Waltham, MA

*The Angi rating for Generator Installation companies in Waltham, MA 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 Waltham, MA 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 June 12, 2025

Reviewed in October 2024
Reasonable rates, professionally done right. Would hire again and highly recommend Brian and his crew and services.
Victory Electrical Services
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Reviewed in April 2019
Well done. Neat work. Friendly and professional technician. There was a bit of a mixup on the timing of the appointment from the office side, so it did not start until 2 hours later than scheduled, but usually Sila is prompt. There was no payment for today's work as it was part of the cost of...
Sila Heating, Cooling, Plumbing and Electrical
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Reviewed in September 2024
With the latest job John and his team completed for us, I am now able to say that for the better part of two decades, the electrical work needs of four generations of my family have been completed by 4th Generation Electric. As John and I were catching up before the install of our transfer...
4th Generation Electric, Inc.
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Reviewed in September 2013
They were very competent. I like there timeliness and they did everything they said they would do.
Rodenhiser Home Services
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Reviewed in June 2024
Ron did an excellent job. I would definitely hire him again. He was knowledgeable and his price was reasonable.
Ronald G Perry
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Reviewed in April 2024
It went very well. Team was excellent. Very professional and neat. On time and kept me up to date on work being done. Erica in the office was terrific and very helpful. Would definitely hire again if needed.
Eight Electric LLC.
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