The Fisher Scientific Isotemp 250LCU Cooling/Heating Recirculating Chiller is a compact temperature-control system designed for analytical instruments, laboratory equipment, reaction systems, and other applications requiring controlled external fluid circulation. With a -10°C to +80°C operating range, approximately ±0.1°C temperature stability, 250 W of cooling capacity at 20°C, and an integrated heater, the 250LCU provides both refrigerated cooling and controlled heating in a relatively small footprint.
Available used and refurbished from American Instrument Exchange, the Fisher Isotemp 250LCU features a compact 2.8 L internal reservoir and a force circulation pump capable of approximately 17 L/min maximum flow. Its combination of heating, refrigeration, external circulation, digital controls, and USB connectivity makes it a versatile alternative to a cooling-only laboratory chiller. A 90-day warranty is included.
Key Features
-10°C to +80°C heating and cooling range
Approximately ±0.1°C temperature stability
250 W cooling capacity at 20°C
Integrated heating system
Compact 2.8 L internal reservoir
Force circulation pump
Maximum pump flow approximately 17 L/min
Maximum pump pressure approximately 300 mbar / 4.35 psi
Five selectable temperature setpoints
USB communication
Digital front-panel controls
Compact laboratory footprint
Designed for quiet operation
Rapid temperature response
Closed-loop external circulation
115 V configuration
Used, refurbished, and tested by American Instrument Exchange
90-day warranty included
Overview
The Fisher Scientific Isotemp 250LCU combines refrigeration, heating, temperature control, and external fluid circulation in a compact laboratory system.
Unlike a conventional cooling-only recirculating chiller, the 250LCU can actively control fluid temperature across both subambient and elevated-temperature applications. Its operating range extends from approximately -10°C to +80°C, making it useful for laboratories that need a single system for both cooling and heating external equipment.
The 2.8 L internal reservoir is intentionally small. Reducing the volume of heat-transfer fluid allows the system to change temperature more quickly than larger-reservoir chillers while also minimizing the amount of coolant required for operation.
The 250LCU uses a force circulation pump designed to deliver approximately 17 L/min at pressures up to approximately 300 mbar. This configuration is well suited for relatively unrestricted external cooling and heating circuits.
An intuitive front-panel interface provides access to temperature controls and five selectable temperature setpoints, while USB connectivity supports communication with compatible laboratory systems.
Key Specifications
Specification
Details
Manufacturer
Fisher Scientific
Product Line
Isotemp
Model
250LCU
Equipment Type
Cooling/heating recirculating chiller
Temperature Range
-10°C to +80°C
Temperature Stability
±0.1°C
Cooling Capacity at 20°C
250 W
Reservoir Capacity
2.8 L / 0.73 gal
Pump Type
Force
Maximum Pump Flow
Approx. 17 L/min
Maximum Pump Pressure
Approx. 300 mbar / 4.35 psi
Programmable Setpoints
5
Communication
USB
Exterior Dimensions
Approx. 9 in. W × 16.5 in. D × 25 in. H
Electrical Requirements
115 V
Warranty
90 days
Common Applications
The Fisher Isotemp 250LCU can be used for a broad range of laboratory applications requiring controlled fluid temperature. Typical applications include chemical reaction control, separations, life-science instrumentation, mass spectrometry, molecular spectroscopy, atomic spectroscopy, surface science, materials characterization, laboratory automation, and general analytical instrumentation.
Its 250 W refrigeration system is particularly appropriate for relatively low heat-load applications where a large process chiller would provide unnecessary cooling capacity and occupy excessive laboratory space.
Because the 250LCU also provides active heating, it can support applications that require temperature cycling or operation above room temperature. This makes it more versatile than a cooling-only recirculating chiller.
The system can also provide a closed-loop alternative to once-through facility-water cooling for compatible low-heat-load instruments.
Ideal Laboratory Types
The Fisher Scientific Isotemp 250LCU is well suited for pharmaceutical and biotechnology laboratories, analytical chemistry facilities, spectroscopy laboratories, materials-science groups, quality-control departments, academic research laboratories, chemical research facilities, and industrial R&D environments.
Its small footprint can be especially useful in laboratories where bench and floor space are limited.
The relatively modest 250 W cooling capacity makes the 250LCU best suited for analytical instruments and experimental systems with low-to-moderate thermal loads rather than high-power lasers, large process equipment, or other applications generating several kilowatts of continuous heat.
Temperature Control & Stability
The Fisher Isotemp 250LCU provides active heating and cooling across a temperature range of approximately -10°C to +80°C with temperature stability of approximately ±0.1°C.
This broad operating range allows a single system to maintain coolant below room temperature, near ambient conditions, or substantially above ambient temperature.
The small 2.8 L reservoir also contributes to rapid temperature response by minimizing the volume of fluid that must be heated or cooled when the setpoint changes.
The refrigeration system provides approximately 250 W of cooling capacity at a 20°C fluid temperature. Available cooling capacity will change as the operating temperature decreases, so applications with significant heat loads should be evaluated according to the required operating temperature rather than the nominal 250 W rating alone.
Appropriate heat-transfer fluid should be selected according to the intended temperature range.
Circulation & Pump Performance
The Fisher Scientific Isotemp 250LCU uses a force circulation pump capable of delivering approximately 17 L/min with maximum pressure of approximately 300 mbar, or 4.35 psi.
This pump configuration favors relatively high fluid flow at modest pressure and is appropriate for external circuits without excessive hydraulic restriction.
The 250LCU should not be confused with the Fisher Isotemp 250LCSU. Although both models provide similar refrigeration capacity and temperature control, the LCSU version uses a force/suction pump with different flow and pressure characteristics.
Actual delivered flow from the 250LCU depends on tubing diameter and length, fittings, fluid viscosity, operating temperature, elevation, and resistance within the connected instrument.
Laboratories should compare these circulation characteristics with the requirements of the equipment being temperature controlled.
Refurbishment & Testing
This used Fisher Scientific Isotemp 250LCU Cooling/Heating Recirculating Chiller is refurbished and tested by American Instrument Exchange before shipment. Our technicians inspect the refrigeration system, heater, force circulation pump, reservoir, temperature controller, display, electrical components, communication functions, safety systems, and external fluid connections.
Temperature-controlled equipment is tested using NIST-traceable probes and data loggers. The system is operated under simulated laboratory conditions to evaluate heating, refrigeration, circulation, temperature regulation, controller operation, and overall stability.
The reservoir and accessible fluid-contact components are cleaned and inspected before shipment.
Customers with specific temperature, flow, or application requirements are encouraged to provide those conditions before shipment. When practical, American Instrument Exchange can incorporate customer-requested operating conditions into final testing.
A 90-day warranty is included with this refurbished Fisher Scientific circulator.
Choosing the Right Circulator or Chiller
The Fisher Isotemp 250LCU is particularly well suited for applications that need precise temperature control but do not require several kilowatts of refrigeration capacity.
Its 250 W cooling system, integrated heater, -10°C to +80°C operating range, and compact 2.8 L reservoir make it useful for smaller analytical instruments, laboratory experiments, and temperature-controlled processes.
Pump requirements should also be considered. The 250LCU's force pump provides relatively high flow at modest pressure. Applications with highly restrictive cooling passages may require a higher-pressure force/suction or positive-displacement pump instead.
Cooling capacity is another important consideration. An instrument producing a relatively small continuous heat load may be an excellent match for the 250LCU, while equipment generating 500 W, 1,000 W, or more may require a larger recirculating chiller.
American Instrument Exchange can help compare available used and refurbished laboratory circulators based on operating temperature, thermal load, pump requirements, electrical service, and instrument compatibility.
Related Equipment
American Instrument Exchange stocks a range of laboratory circulators, including Fisher Scientific Isotemp circulators, refrigerated/heated bath systems, recirculating chillers, and high-capacity process cooling systems. Laboratories considering the Fisher 250LCU may also want to compare available laboratory water baths, reactors and fermenters, evaporators and extractors, and other refurbished laboratory equipment.
What is the temperature range of the Fisher Isotemp 250LCU?
The 250LCU provides both heating and cooling across a temperature range of approximately -10°C to +80°C.
How much cooling capacity does the 250LCU provide?
The Fisher Isotemp 250LCU provides approximately 250 W of cooling capacity at a 20°C fluid temperature.
Does the Fisher 250LCU provide heating?
Yes. Unlike a cooling-only recirculating chiller, the 250LCU includes an integrated heater and can maintain fluid temperatures up to approximately 80°C.
What is the reservoir capacity?
The 250LCU has a compact 2.8 L internal reservoir. Its relatively small fluid volume helps provide faster temperature response while reducing the amount of heat-transfer fluid required.
What type of pump does the 250LCU use?
The 250LCU uses a force circulation pump capable of approximately 17 L/min maximum flow at up to approximately 300 mbar, or 4.35 psi.
What is the difference between the 250LCU and 250LCSU?
The primary difference is pump configuration. The 250LCU uses a force pump, while the 250LCSU uses a higher-pressure force/suction pump. The appropriate model depends on the hydraulic requirements of the connected equipment.
Is the Fisher 250LCU suitable for analytical instruments?
Yes. Fisher designed these systems for applications including mass spectroscopy, molecular and atomic spectroscopy, life-science instrumentation, materials characterization, laboratory automation, and other analytical equipment.
Does this refurbished Fisher Isotemp 250LCU include a warranty?
Yes. This used Fisher Scientific Isotemp 250LCU is refurbished and tested by American Instrument Exchange and includes a 90-day warranty.
CLICK HEREto see the Fisher Scientific Isotemp 250LCU cooling/heating recirculating chiller on our YouTube channel
Testing Procedures for Used and Refurbished Laboratory Equipment
Ensure Accuracy, Safety, and Dependable Performance Across Applications
At American Instrument Exchange, all used and refurbished laboratory equipment undergoes a rigorous, multi-point testing protocol to ensure optimal performance, operational safety, and long-term reliability. Whether the equipment is destined for research, diagnostics, quality control, or production environments, our thorough inspection and testing process is designed to meet the highest standards of laboratory excellence.
Why Testing Used Lab Equipment Is Essential
Before any refurbished laboratory equipment is returned to service, it must be carefully tested to verify:
• Functional integrity and operational performance
• Setpoint accuracy and repeatability (where applicable)
• User interface responsiveness and control features
Proper testing reduces the risk of equipment failure, measurement inaccuracies, or user hazards—helping to ensure consistent results in clinical, academic, biotech, and industrial labs.
Our standardized lab equipment testing procedures are tailored to each equipment type, ensuring every unit meets manufacturer specifications and industry benchmarks.
Key Testing Procedures for Refurbished and Used Laboratory Equipment
1. Initial Visual Inspection
• Examine equipment housing for signs of wear, corrosion, or damage
• Check ports, power cords, and exterior components for tampering or deterioration
• Verify that internal and external parts (racks, shelves, connectors, accessories) are present and undamaged
2. Functional Startup and Operational Testing
• Power on the equipment and verify startup diagnostics
• Confirm functionality of displays, buttons, switches, and control panels
• Run basic functions to confirm proper response and behavior under standard operating conditions
3. Testing and Performance Verification
• Test internal sensors or control systems using industry-standard tools
• Perform operational tests to validate accuracy and consistency
• Verify key performance specifications such as temperature control, timing, speed, or measurement outputs, depending on equipment type
4. Mechanical and Electrical System Testing
• Evaluate motors, pumps, fans, or other moving parts for smooth operation
• Inspect and test wiring, relays, fuses, and circuit boards for safety and reliability
• Test power delivery and grounding compliance
5. Safety and Compliance Checks
• Ensure equipment is grounded and insulated to meet laboratory safety standards
• Test alarms, interlocks, emergency stops, or safety shutdown systems if applicable
6. Final Quality Assurance and Documentation
• Perform extended runtime testing
• Document operational logs, testing results, and any repairs or adjustments made
• Complete a final inspection, thorough cleaning, and packaging for delivery
Trusted Quality from American Instrument Exchange
With over 50 years of experience in laboratory equipment refurbishment, American Instrument Exchange is committed to delivering certified, lab-ready instruments backed by expert testing. Our testing protocols ensure that each piece of equipment—regardless of type—is safe, accurate, and dependable from day one.
Whether you're equipping a startup lab or expanding a high-throughput facility, you can count on our refurbished laboratory equipment to perform with precision and reliability.
Refurbishment Protocol for Used Laboratory Equipment from American Instrument Exchange
At American Instrument Exchange, every piece of used laboratory equipment we offer undergoes a multi-step refurbishment process. Whether it's an analytical balance, centrifuge, freezer, oven, or any other essential lab instrument, our goal is to restore each unit to peak performance—ensuring accuracy, safety, and long-term reliability in scientific, clinical, industrial, and academic environments.
Why Choose Refurbished Lab Equipment from American Instrument Exchange?
• Thoroughly tested for performance, precision, and safety
• Backed by a warranty
• A cost-effective alternative to new equipment
• Environmentally sustainable through equipment reuse and waste reduction
• Serviced by expert technicians with decades of laboratory equipment experience
Step-by-Step Refurbishment Protocol
Every instrument and system refurbished at American Instrument Exchange follows a detailed, industry-aligned process:
1. Initial Intake & Inspection
• Complete visual and structural inspection for cosmetic damage, wear, or corrosion
• Mechanical assessment of hinges, seals, fasteners, motors, and moving parts
• Missing components and damaged items are documented for repair or replacement
2. Cleaning and Decontamination
• Full internal and external cleaning using non-abrasive, lab-safe solutions
• Removal of biological, chemical, or particulate contamination
• Disassembly and cleaning of removable parts such as trays, shelves, and filters
3. Mechanical and Electrical Repair
• Replacement or repair of worn or broken mechanical parts
• Evaluation and servicing of control panels, sensors, switches, and displays
• Testing and repair of electrical wiring, fuses, circuit boards, and power supplies
4. Functional System Testing
• Assessment of all major functions specific to the equipment type (e.g., speed, temperature, force, weight, timing)
• Operation of control interfaces, programming menus, and digital displays
• Verification of stabilization time, responsiveness, and user input reliability
5. Testing and Performance Verification
• Testing of internal sensors, controllers, and measurement systems using certified tools
• Multi-point testing to ensure repeatability, accuracy, and performance consistency
• Confirmation of user-defined setpoints, timing sequences, or programmable cycles
6. Safety and Compliance Checks
• Testing of safety interlocks, alarms, and over-limit protection systems (as applicable)
• Electrical safety inspections, including grounding and insulation verification
7. Final Quality Assurance and Documentation
• Full operational testing under simulated lab conditions
• Completion of performance benchmarks, testing results, and repair logs
• Final cleaning and visual inspection
Trust the Experts at American Instrument Exchange
With over 50 years of experience in the laboratory equipment industry, American Instrument Exchange is a trusted leader in high-quality refurbished lab instruments. Our refurbishment protocols ensure that every piece of equipment we sell is lab-ready—offering the precision, performance, and durability your team can count on.
Whether you’re outfitting a new lab or expanding an existing operation, choose American Instrument Exchange for tested, warrantied, and cost-effective laboratory equipment.
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.
