
Used Diesel Generators for Sale
Find high-quality, inspected used diesel generators for your commercial or industrial needs.
Save on costs, ensure rapid deployment, and rely on our multi-point inspection & warranty.
Used Diesel Generators for Reliable, Cost-Effective Power
Purchasing a high-quality, inspected used diesel generator from Generator Source offers commercial and industrial buyers significant cost savings (often 30-70% less than new), rapid availability for urgent power needs, and proven reliability. All our units undergo rigorous multi-point inspections, providing exceptional value for operations across Colorado, Florida, and Texas.
Significant Cost Savings
Up to 70% off new equipment
Rapid Deployment
In-stock inventory, ready to ship
Guaranteed Quality
31-point inspection
Leading Brands
Cat, Cummins, Kohler, & more
Expert Support
Sizing, installation & ongoing service
Variety of Capacities
20kW-4000kW options
Compare Used Diesel Generators
Select up to five used diesel generators from our inventory to view a detailed side-by-side comparison of their specifications.
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Benefits of Used Diesel Generators from Generator Source
- Why Choose a Used Diesel Generator from Generator Source?
Investing in a used diesel generator from Generator Source provides your commercial or industrial operation with robust, dependable power without the premium price tag. We understand that your budget and operational timelines are critical, which is why our high-quality used units offer an unbeatable combination of value and performance. - Cost Efficiency Without Compromise
Acquiring a used diesel generator is a strategically smart financial decision. Our rigorously inspected and reconditioned units provide the same essential power capabilities as new equipment but typically at a fraction of the cost – often saving you 30% to 70%. This significant reduction in capital expenditure allows you to allocate resources more efficiently while still securing premium, reliable power for your critical operations. You get uncompromising performance and durability, all within a budget-friendly framework. - Immediate Availability & Rapid Deployment
In today’s fast-paced business environment, waiting weeks or even months for a new generator is simply not an option for urgent power needs or unexpected demands. Generator Source specializes in immediate availability. Our extensive inventory of used diesel generators is already in-stock and ready to ship from our facilities across Colorado, Florida, and Texas. This means significantly shorter lead times compared to new equipment, allowing for rapid deployment and minimizing costly operational downtime. When you need power now, we deliver.
- Proven Reliability in Real-World Applications
Many of the used diesel generators in our inventory have a history of proven performance in demanding commercial and industrial settings. These units have already demonstrated their inherent durability and capability in real-world applications, offering a track record of reliability. Our meticulous 31-point inspection, testing, and reconditioning process ensures that any unit we sell meets stringent operational standards, confirming its continued dependability for your specific power requirements. - Reduced Environmental Impact
Choosing a used diesel generator is also a step towards greater sustainability for your business. By repurposing existing, high-quality equipment, you contribute to a circular economy, reducing the demand for new manufacturing resources and minimizing waste. This environmentally conscious decision aligns with modern corporate responsibility goals, offering a greener power solution without sacrificing performance or reliability.
Our Rigorous 31-Point Inspection
Standard Tests
- Grease Gen Bearing
- Tighten Hose Clamps
- Check Oil & Condition
- Check Coolant (Full & Protected for Temp)
- Turn Engine for 2 Full Rounds
- Remove Remote Wires
- Tighten All Term Screws
- Check Air Filter
- Check Barrel Leads (Insul. Tightness)
- Voltage Check
- Check Fan Belts
- Missing Belts
- Check Block Heater
- Remote Start Connection (Locate, Test & Tag)
- Fuel Pumped Out of Tank
- Battery Voltage (12 or 24 Volt)
- Cold Water Leaks
- Check Fuel Rack
- Check Battery Cables
- Check Battery Charger
Load Bank Tests
- Check Temperature with Heat Gun
- Coolant Leaks
- Oil Leaks
- Full Rating Tests
- Gauge Compliance Tests
- Gauge Adjustment Tests
- Accurate Temperature Gauge Test
- Engine Alternator Test
- Pre-Alarm Verification
- Shut Down Verification
- Auto Start Test & Tag Verifications
Explore Our Diverse Inventory of Used Diesel Generators
Showing 12 of 236 results
- More Details
Three-Phase
Fuel: Diesel
Built: 2009
Volts: 13800
Hours: 691
Unit #: 091894
- More Details
Three-Phase
Fuel: Diesel
Built: 2011
Volts: 277/480v
Hours: 279
Unit #: 091800
- More Details
Three-Phase
Fuel: Diesel
Built: 2011
Volts: 277/480v
Hours: 273
Unit #: 091801
- More Details
Three-Phase
Fuel: Diesel
Built: 2013
Volts: 277/480v
Hours: 5
Unit #: 091773

Need help finding a generator?
Not sure where to start with your power system? Our team is here to help. Generator projects involve many factors – from sizing and site preparation to compliance – so it’s wise to consult with our experts (and your electrical engineers) early in the process. We can assist in selecting the optimal unit or paralleling setup and ensure all technical requirements are met before purchase and installation.
Our Values
Our mission is to provide reliable power solutions that empower businesses across industries, ensuring seamless operations with unmatched expertise and quality.
Since our founding over four decades ago, Generator Source has grown to become the country’s largest buyer and seller of commercial generators, with branches and service teams ready to deliver power solutions nationwide.


People First
We prioritize relationships, building trust and respect in every customer and team interaction.

Quality of work
We hold ourselves to the highest standards, delivering reliable power solutions backed by rigorous testing.

Dedication
We go the extra mile to support our customers and stand behind every generator we service and sell.

Expertise
With 50 years of industry experience, our team brings unmatched knowledge to every project.
Ideal Power Solutions for Commercial & Industrial Applications
Powering a world of industries. From office buildings to hotels, universities to airports, generators are essential to keep businesses running smoothly. Here are just a few of the industries we proudly serve, ensuring reliable power when it’s needed most:
Powering a world of industries. From office buildings to hotels, universities to airports, generators are essential to keep businesses running smoothly. Here are just a few of the industries we proudly serve, ensuring reliable power when it’s needed most:
Construction
From large-scale infrastructure projects to smaller builds, generators are indispensable on construction sites. They power heavy machinery like cranes and mixers, as well as essential equipment such as lighting and hand tools. Portable and trailer-mounted generators ensure seamless operations.
Data Centers
Generators provide critical backup for data centers to maintain uptime and protect sensitive information. They power servers, cooling systems, and network infrastructure during outages, ensuring uninterrupted operations for businesses, cloud storage, and internet services.
Hospitality
Hotels, resorts, and venues use generators to maintain operations during outages, power elevators, kitchens, and HVAC systems. Backup generators are also essential for outdoor events and conferences, ensuring guest experiences are uninterrupted regardless of power challenges.
Agriculture
Generators in agriculture keep operations running smoothly, powering irrigation systems, milking machines, and storage facilities. For farms in remote areas, they also run essential equipment, ensuring livestock care and crop preservation.
Hospitals
In hospitals, generators power life-saving equipment, operating rooms, and essential systems during power failures. These generators support critical areas like ICUs and labs, ensuring seamless care and patient safety in any emergency.
Cold Storage
Cold storage facilities rely on generators to maintain temperature-controlled environments for perishable goods. Whether it’s food, pharmaceuticals, or other sensitive items, generators prevent spoilage and protect inventory.
Frequently Asked Questions About Our Used Diesel Generators
- Why should I consider buying a used diesel generator instead of a new one?
Buying a used diesel generator offers significant cost savings, often at a fraction of the price of a new unit. They also typically have faster availability, as new generators can have long lead times. When sourced from a reputable dealer like Generator Source, our used units undergo rigorous testing and reconditioning, providing a reliable and cost-effective power solution. - What is your reconditioning and testing process for used generators?
Every used generator at Generator Source goes through a comprehensive multi-point inspection and reconditioning process. This includes fluid analysis, load bank testing to ensure full power output, component checks, and replacement of any worn parts. Our goal is to ensure the unit performs to factory specifications, ready for reliable service. You can learn more about our process here. - Do your used generators come with a warranty?
Yes, many of our used diesel generators come with a limited warranty, providing you with peace of mind. The specific warranty details can vary depending on the age, make, and model of the generator. We will clearly outline the warranty coverage for each unit you consider. - How do I know what size used generator I need?
Determining the correct generator size is crucial. We recommend a professional load analysis of your facility’s power requirements. Our sales engineers are experienced in helping customers calculate their power needs to ensure you select a used generator that is appropriately sized for your application. You can use our Generator Sizing Calculator here. - What is the typical lifespan of a used diesel generator?
Diesel generators are built for durability and have an inherently long lifespan. A well-maintained used diesel generator, especially one that has undergone our reconditioning process, can provide many years of reliable service. Factors like previous maintenance, operating hours, and ongoing preventative maintenance contribute to its longevity. We provide detailed hour meter readings for all our units. - Can you deliver and install the used generator?
Yes, we offer delivery services for our used generators to your location. While we do not typically handle installation directly, we can recommend qualified professionals or provide guidance to your chosen installer to ensure proper setup and commissioning of the unit. - What if I need parts or service for a used generator after purchase?
Generator Source maintains a vast inventory of parts for a wide range of diesel generator brands and models. We can assist you in finding the right parts for your unit. We also have a network of trusted service partners, and our technical support team is available to assist with any operational questions you may have post-purchase. - How do you determine the price of a used generator?
The price of our used generators is based on several factors, including the make, model, age, hours of operation, condition, and current market demand. Our pricing reflects the quality and reliability assured by our comprehensive reconditioning and testing process, providing excellent value for your investment. - Can I inspect the used generator before purchasing?
Absolutely! We encourage potential buyers to visit our facility to inspect units in person if possible. We also provide detailed photos, videos, and specifications for each generator online to give you a thorough understanding of its condition and features before you make a decision. - What kind of fuel efficiency can I expect from a used diesel generator?
Diesel generators are known for their fuel efficiency, especially under load. While exact consumption varies by generator size, load, and engine condition, our reconditioned units are tuned for optimal performance. We can provide estimated fuel consumption data for specific models based on manufacturer specifications and load bank test results. - Are your used diesel generators certified or inspected by independent third parties?
While our internal inspection and reconditioning process is exhaustive, we can often provide documentation of past certifications or facilitate third-party inspections if required for your specific project. Our transparency ensures you know exactly what you’re getting. - How can I verify the actual operating hours of a used generator?
All our used generators come with hour meter readings. During our inspection process, we verify the functionality of the hour meter and cross-reference with any available maintenance records to ensure accuracy to the best of our ability, providing full transparency to the buyer. - What is the typical purchasing process for a used generator from Generator Source?
Our process is designed to be straightforward. It typically involves initial consultation to determine your needs, selection from our inventory, receipt of a detailed quote, arrangement of financing (if needed), reconditioning and final testing, and then delivery to your site. Our team guides you every step of the way. - Do you ship used diesel generators internationally?
Yes, Generator Source has extensive experience shipping used generators globally. We can handle the logistics, documentation, and customs requirements to ensure your generator arrives safely and efficiently at its international destination. - Do you offer financing options for used diesel generators?
We understand that purchasing a generator can be a significant investment. We work with various financing partners to offer competitive financing solutions for qualified buyers, making it easier to acquire the power equipment you need. - What are the benefits of an open versus an enclosed used diesel generator?
- Open generators are often more cost-effective and provide easier access for maintenance but require a separate enclosure for noise reduction and weather protection. Enclosed (sound-attenuated) units are designed for quieter operation and outdoor placement, making them ideal for urban or noise-sensitive environments. Your specific needs will dictate the best choice.
- Do you offer used mobile or trailer-mounted diesel generators?
Yes, our inventory frequently includes used mobile and trailer-mounted diesel generators, perfect for construction sites, events, or any application requiring portable power. These units come fully reconditioned and ready for transport and immediate use. - What are the long-term benefits of investing in a high-quality used diesel generator?
A well-maintained used diesel generator from a reputable supplier offers significant long-term value. Beyond initial cost savings, diesel engines are renowned for their durability and fuel efficiency, translating into lower operational costs and a strong return on investment over many years of reliable performance. - How much can I save by buying a used diesel generator compared to a new one?
Savings can vary significantly, often ranging from 30% to 70% or more compared to the cost of a comparable new unit. These savings are achieved without compromising on performance or reliability, thanks to our rigorous inspection and reconditioning processes. - Do used diesel generators meet current emissions standards?
Many newer used diesel generators are designed to meet various EPA and local emissions standards. We provide detailed specifications for each unit, including its emissions tier, to help you ensure compliance with regulations in your operating area. Older units may require specific considerations or modifications depending on local laws. - How often does your inventory of used diesel generators change?
Our inventory is constantly evolving. We acquire and recondition new units regularly, so it’s always a good idea to check our website frequently or contact our sales team directly with your specific requirements. If we don’t have what you need today, we might have it tomorrow. - Do you purchase or accept trade-ins for used generators?
Yes, we are always looking to expand our inventory of quality used generators. If you have a generator you’re looking to sell or trade in, please contact us with details about your unit, and we’ll be happy to provide a fair assessment and offer.
Find Your Ideal Used Diesel Generator Today
Generator Source specializes in low-hour, used, new, and surplus diesel generator sets. We have a wide variety of generator sizes and models to fit any project. We are not a broker, we own what we sell. Call us today (877-866-6895) or click Contact Us to be connected with one of our experienced sales reps.
We have 350+ generators in stock and ready to ship!
