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Thermo Fisher General Purpose Undercounter Refrigerator – Model 3751FS
The Thermo Fisher General Purpose Undercounter Refrigerator, Model 3751FS, is a compact laboratory refrigerator designed to provide dependable refrigerated storage while conserving valuable laboratory floor space. With 5.6 cubic feet (159 L) of storage capacity and an adjustable operating temperature range of 1°C to 12°C, the 3751FS is ideal for biotechnology laboratories, pharmaceutical companies, hospitals, universities, and industrial research facilities requiring reliable point-of-use refrigeration for reagents, media, biological samples, and other laboratory materials.
Designed specifically for laboratory environments, the 3751FS delivers more consistent temperature performance than residential compact refrigerators while maintaining a compact undercounter footprint. Its mechanical thermostat, manual defrost refrigeration system, adjustable shelving, and durable cabinet construction make it an excellent choice for laboratories seeking economical, dependable refrigerated storage.
Refurbished and performance tested by American Instrument Exchange
90-day warranty included.
Overview
The Thermo Fisher 3751FS is engineered for laboratories that require dependable refrigerated storage without dedicating valuable floor space to a full-size upright refrigerator. Its undercounter design allows installation beneath laboratory benches, keeping frequently used materials close to the point of use while improving workflow efficiency.
The refrigerator utilizes a hermetically sealed refrigeration system with manual defrost operation to provide reliable cooling for routine laboratory applications. Four adjustable wire shelves allow flexible organization of bottles, reagents, and laboratory supplies, while the compact cabinet fits comfortably into laboratories where space is limited.
Common Applications
The Thermo Fisher 3751FS is commonly used for storing laboratory reagents, buffers, biological samples, cell culture media, pharmaceutical products, quality-control materials, calibration standards, diagnostic supplies, and other non-critical laboratory materials requiring dependable refrigerated storage. Its compact footprint makes it particularly useful in analytical laboratories, cleanrooms, research workstations, hospital laboratories, and satellite laboratory locations where refrigerated storage is needed within easy reach of laboratory personnel.
Ideal Laboratory Types
Biotechnology laboratories
Pharmaceutical manufacturers
Academic research laboratories
Clinical laboratories
Hospitals
Environmental laboratories
Industrial quality assurance laboratories
Government research facilities
Why Choose the Thermo Fisher 3751FS?
The 3751FS provides reliable laboratory refrigeration in a compact package that maximizes available workspace. Its laboratory-specific construction, dependable refrigeration system, and straightforward controls make it an excellent choice for laboratories seeking affordable, reliable refrigerated storage without the complexity of premium monitoring systems.
Typical Stored Materials
The Thermo Fisher 3751FS is commonly used to store laboratory reagents, biological specimens, media, antibodies, enzymes, calibration standards, quality-control samples, pharmaceutical products, diagnostic supplies, and other laboratory materials requiring refrigerated storage.
Thermo Fisher 3751FS Key Specifications
Identification
Manufacturer: Thermo Fisher
Model:3751FS
Product Type: General Purpose Undercounter Laboratory Refrigerator
Capacity
5.6 cu. ft. (159 L)
Temperature Range
1°C to 12°C
Construction
Solid insulated door
Four adjustable wire shelves
Painted steel cabinet
Compact undercounter configuration
Refrigeration System
Hermetically sealed compressor
Manual defrost
Mechanical thermostat
Monitoring & Controls
Adjustable mechanical temperature control
Electrical Requirements
120V, 60 Hz
Exterior Dimensions
23.6" W × 29.0" D × 33.5" H
Interior Dimensions
20.0" W × 16.0" D × 27.5" H
Weight
80 lbs.
Operating Costs & Energy Considerations
The 3751FS utilizes a reliable hermetic compressor and insulated cabinet to provide dependable refrigerated storage with economical operating costs. Routine condenser cleaning and adequate ventilation around the cabinet will help maximize cooling efficiency and extend the service life of the refrigeration system.
Specifications compiled from Thermo Fisher manufacturer literature and American Instrument Exchange product information.
Refurbishment & Testing Process
Every Thermo Fisher 3751FS received by American Instrument Exchange undergoes a comprehensive inspection before shipment. Our technicians verify temperature accuracy using calibrated temperature monitoring equipment, inspect the refrigeration system, thermostat, shelving, door gasket, hinges, compressor, and overall cabinet condition. Each refrigerator is thoroughly cleaned, temperature tested, and verified for dependable laboratory operation before shipment.
The Thermo Fisher 3751FS ships by freight from American Instrument Exchange. Before installation, verify cabinet clearances, electrical service, and ventilation requirements. Allow the refrigerator to stabilize at operating temperature before loading temperature-sensitive laboratory materials.
Frequently Asked Questions
What is the model number of this refrigerator?
This refrigerator is the Thermo Fisher Model 3751FS.
How much storage capacity does the 3751FS provide?
The refrigerator provides 5.6 cubic feet (159 liters) of refrigerated laboratory storage.
What temperature range does the 3751FS maintain?
The refrigerator operates over an adjustable temperature range of 1°C to 12°C.
How is the refrigerator tested before shipment?
Every refurbished Thermo Fisher 3751FS is inspected and temperature tested by American Instrument Exchange technicians. Refrigeration performance, thermostat operation, shelving, door seal, and overall cabinet functionality are verified before shipment.
CLICK HEREto see the Fisher Scientific 3751FS general purpose undercounter refrigerator on our YouTube channel
Testing Procedures for Used and Refurbished Laboratory Refrigerators Ensure Temperature Stability and Cold Storage Accuracy
Used and refurbished laboratory refrigerators from American Instrument Exchange are thoroughly tested to ensure reliable cold storage performance, temperature accuracy, and compliance with laboratory safety and storage standards. Each unit undergoes a detailed inspection and functional verification to meet the requirements of clinical, pharmaceutical, research, and industrial labs.
Why Testing Used Laboratory Refrigerators Is Essential
Before a laboratory refrigerator is reintroduced into any laboratory setting, it must be carefully tested for:
• Temperature uniformity and stability
• Cooling system integrity and compressor function
• Door seal performance and insulation effectiveness
• Electrical safety and compliance with lab standards
Thorough testing minimizes the risk of temperature excursions, product loss, and system failures—especially critical for storing reagents, vaccines, biological samples, pharmaceuticals, and temperature-sensitive materials.
Our structured testing protocol ensures refurbished lab refrigerators deliver consistent, dependable performance across all makes and models.
Key Testing Procedures for Refurbished and Used Laboratory Refrigerators
1. Initial Visual Inspection
• Check exterior surfaces, hinges, and door gaskets for wear, corrosion, or damage
• Inspect power cords, plugs, and control panels for fraying or visible defects
• Verify that shelves, racks, and internal compartments are present and functional
2. Functional Testing
• Power on the refrigerator and verify that display screens, alarms, and controls function properly
• Test door latches and sealing mechanisms to ensure secure closure and insulation
• Run preliminary temperature cycles to observe startup behavior and cooling response
3. Temperature and Stability Testing
• Test internal temperature sensors and controllers using thermometers/probes
• Monitor temperature at multiple points within the chamber over an extended period
• Verify accuracy across user-defined setpoints (e.g., +4°C, +2°C to +8°C range)
4. Cooling System and Compressor Evaluation
• Test compressor startup, cycling, and operating noise levels
• Inspect condenser coils and fans for proper function and cleanliness
• Check refrigerant pressure (if applicable) and confirm there are no leaks or system inefficiencies
5. Electrical Safety and Compliance Checks
• Ensure all internal and external electrical components are properly grounded
• Perform insulation resistance and leakage current tests 6. Final Quality Assurance Checklist
• Run full operational tests over a 24-hour period
• Document temperature logs, control responsiveness, and system performance
• Complete a detailed service report
All refurbished laboratory refrigerators from American Instrument Exchange are backed by our rigorous testing standards and quality commitment. From vaccine storage to reagent preservation, you can count on consistent cold storage performance from day one.
Repair and Refurbishment Protocol for Used Laboratory Refrigerators Cold Storage Performance from American Instrument Exchange
At American Instrument Exchange, every used laboratory refrigerator we offer is subjected to a comprehensive repair and refurbishment protocol. Whether it’s a general-purpose lab refrigerator, pharmaceutical-grade unit, or undercounter model, our goal is to restore each system to peak performance—ensuring consistent temperature control and reliable to laboratory storage standards.
Why Choose a Refurbished Laboratory Refrigerator from American Instrument Exchange?
• Fully tested for cold storage accuracy and operational safety
• Backed by a warranty
• Cost-effective alternative to new refrigeration equipment
• Sustainably refurbished to reduce environmental impact
• Serviced by expert technicians with decades of laboratory equipment experience
Step-by-Step Refurbishment Protocol
Every laboratory refrigerator from American Instrument Exchange follows a detailed, multi-stage process to ensure top-tier performance and reliability:
1. Initial Intake & Inspection
• Visual inspection for dents, corrosion, or structural damage
• Mechanical check of door hinges, gaskets, seals, and internal components
• Documentation of missing parts or areas requiring repair or replacement
2. Cleaning and Decontamination
• Internal and external cleaning using non-abrasive, lab-safe cleaners
• Decontamination/cleaning of all surfaces to remove biological or chemical residues
• Thorough cleaning of shelving, drawers, and removable interior parts
3. Mechanical and Electrical Repairs
• Replacement or repair of worn mechanical parts (door latches, seals, hinges, etc.)
• Inspection and restoration of control interfaces, thermostats, sensors, and displays
• Evaluation of wiring, relays, fuses, and power supply components for safety and integrity
4. Refrigeration System and Compressor Evaluation
• Testing of compressor function, condenser coils, and evaporators
• Inspection for refrigerant leaks and pressure performance (if applicable)
• Verification of proper airflow, fan operation, and defrost cycles
5. Temperature and Performance Testing
• Testing of temperature sensors and control boards
• Verification of temperature stability and uniformity throughout the chamber
• Testing of multiple setpoints (e.g., +2°C to +8°C) over extended operating periods
6. Safety and Compliance Checks
• Inspection of grounding and electrical insulation per lab safety standards
• Testing of alarm systems (if applicable) for temperature excursions or power failure
7. Final Quality Control and Documentation
• Multi-day operational test under real-world conditions
• Final cleaning, inspection, and performance validation
• Detailed service report with temperature logs, repair notes, and certification of refurbishment
Trust the Experts at American Instrument Exchange
With over 50 years of industry experience, American Instrument Exchange is a leading provider of high-quality refurbished laboratory equipment. Our proven laboratory refrigerator refurbishment protocol ensures consistent, accurate cold storage—so you can safeguard your samples, reagents, and research materials with confidence.
Warranty Information
All used equipment sold by American Instrument Exchange is refurbished/reconditioned, tested to meet specifications, cleaned, and comes with a 90-day warranty from the date of shipment unless otherwise specified. New products include a warranty from the manufacturer. Your warranty is only valid if you have paid your invoice. If your invoice is over 30 days old, warranty work will not be performed until your invoice is paid in full. American Instrument Exchange is not liable for any special or consequential damages that result from the use of, or the inability to use, the materials on this site or the performance of the products,
Exceptions include international sales and items that are agreed to be sold with a lesser warranty or items that are agreed to be sold “as is.”
Should there be visible shipping damage to packaging or concealed shipping damage to item(s) supplied, buyer must communicate such damage to the delivering entity or carrier upon receipt first and to American Instrument the same day item is accepted / signed for. Failure to do so voids warranty. Customer decision to involve / procure third party or OEM service other than American Instrument or AIE assigned vendors to resolve in-warranty instrument failure or defect without first placing a service call to American Instrument voids warranty.
Return & Cancellation Policy
American Instrument Exchange will authorize the return of and issue a full refund for any equipment that is not working as represented and could not be replaced or repaired to the customer’s satisfaction by AIE or a representative of AIE during the warranty period. Returns without prior authorization and an RMA number will not be accepted.
Customers are responsible for proper packaging of the equipment and all included accessories. American Instrument will pay for insurance and shipping costs. Non-inventory items bought specifically to fill customer orders may possibly be returned, but on a case by case basis.
Customers who cancel orders after refurbishing has begun or after delivery where there are no equipment performance issues may be subject to a Restocking/Cancellation Fee of 20% or more and responsible for shipping costs for both the delivery and return.
Ongoing and Extended Support Options
American Instrument Exchange is able to provide additional repair and support services outside the warranty terms for most products that sell.
For biosafety cabinets, clean benches, chemical fume hoods, and other clean air products our team at AIE Laboratory Services can provide certifications, repairs, decontaminations, and other services for customers throughout New England, and guidance and limited technical assistance for any customers in the US and Canada for new or refurbished biosafety cabinets purchased from American Instrument Exchange.
For all other products, the repair service team at American Instrument Exchange can provide both field and depot repair evaluations. We can easily schedule and coordinate the pick-up and transportation of your malfunctioning equipment. By offering hourly rates lower than most OEM service providers and eliminating travel time for technicians, we help reduce repair costs. Furthermore, our lab depot repair service minimizes or eliminates scheduling delays. Our experienced service technicians are qualified to restore your equipment to factory specifications.
Yes, all equipment from American Instrument Exchange comes with a warranty. Used/reconditioned/refurbished equipment is tested to make sure it operates to the manufacturer's specifications and comes with a 90-day warranty (unless otherwise noted). New equipment comes with a warranty from the manufacturer.
How do you test and recondition the equipment?
Testing requirements vary across all the equipment categories we sell. Temperature controlled units are tested with NIST traceable probes and data loggers. Gaskets, external housing, glass, handles, controls and control screens are all thoroughly inspected for integrity and functionality. We test all equipment using the manufacturer's parameters and specifications to confirm that the unit operates properly.
How do products ship from American Instrument Exchange?
We can ship products both nationally and internationally using a well-established network of transporters. Smaller items will ship via UPS. Larger equipment will be palletized and shipped either LTL or air-ride, depending on the specific equipment and/or delivery requirements.
Return and order cancellation policy
American Instrument Exchange will accept the return of any product that is not working as represented and could not be replaced or repaired to the customer's satisfaction during the warranty period. Customers who cancel orders after refurbishing has begun will be subject to a cancellation and restocking fee of between 20% and 40%.
Are discounts available for educational or non-profit institutions, or for bulk purchases?
Yes – call or email us today with a list of equipment you're looking for and we can potentially put together a quote that includes a discount.
How does your price matching policy work?
We strive to keep our pricing competitive and reasonable. If you find comparable items for sale at a lower price from other vendors please send us a link and or quote for the item and we'll do our best to match or beat the price.
Can I see the equipment in person before committing to a purchase?
Customers are welcome to make an appointment to view equipment in our warehouse. Given our workload we may not be able to test or clean the equipment prior to your arrival if you have not committed to an order.
1023 Western Avenue is a working warehouse, not a showroom, and customers should dress appropriately and wear closed toe shoes.
Can I ship products that I purchased elsewhere to American Instrument for repair?
Yes – please see our repair services page for more information.
