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Fisher Scientific Isotemp 3028H Heated Circulating Water Bath
The Fisher Scientific Isotemp 3028H Heated Circulating Water Bath is a large-capacity laboratory bath designed for precise heating, active fluid circulation, and both internal and external temperature-control applications. With a 28 L reservoir and an operating temperature range from approximately ambient +15°C to 150°C, the 3028H provides considerably more working volume than compact circulating baths while maintaining a relatively manageable benchtop footprint.
Available used and refurbished from American Instrument Exchange, the Fisher Isotemp 3028H is well suited for sample incubation, reagent warming, temperature conditioning, calibration procedures, materials testing, and compatible external circulation applications. Its integrated circulation pump continuously moves fluid throughout the reservoir to promote better temperature uniformity than a basic non-circulating water bath. A 90-day warranty is included.
Key Features
Large 28 L bath capacity
Temperature range from ambient +15°C to 150°C
0.1°C digital display resolution
Active fluid circulation for improved bath uniformity
Suitable for direct immersion applications
Can circulate heated fluid to compatible external equipment
Large working area for multiple samples or larger vessels
Digital temperature control
Industrial-grade circulation pump
Compact footprint relative to its 28 L capacity
115 V, 60 Hz operation
Used, refurbished, and tested by American Instrument Exchange
90-day warranty included
Overview
The Fisher Scientific Isotemp 3028H combines the working space of a large laboratory water bath with the performance advantages of active fluid circulation. Its 28 L reservoir provides substantial room for samples, containers, calibration devices, and other laboratory materials requiring controlled heating.
Unlike a basic water bath that depends primarily on natural convection to distribute heat, the 3028H continuously circulates fluid through the reservoir. This forced circulation helps reduce temperature gradients and promotes more consistent conditions throughout the working bath, particularly when the reservoir contains multiple samples or larger immersed loads.
The circulation system can also be used to pump temperature-controlled fluid to compatible external equipment. This allows the 3028H to function both as a direct immersion bath and as a heated external circulator.
With a maximum operating temperature of 150°C, the 3028H can also support elevated-temperature applications beyond the practical range of conventional water when an appropriate heat-transfer fluid is used.
Key Specifications
Specification
Details
Manufacturer
Fisher Scientific
Series
Isotemp
Model
3028H
Equipment Type
Heated circulating water bath
Bath Capacity
28 L
Temperature Range
Ambient +15°C to 150°C
Display Resolution
0.1°C
Circulation
Internal and compatible external circulation
Control
Digital temperature control
Approx. Bath Dimensions
12 in. L × 11 in. W × 8 in. H
Approx. Exterior Dimensions
23 in. L × 13 in. W × 16 in. H
Electrical Requirements
115 V, 60 Hz, 15 A
Application Type
Direct immersion and external temperature control
Warranty
90 days
Common Applications
The Fisher Isotemp 3028H can support a broad range of laboratory procedures requiring controlled and uniform heating. Typical applications include sample incubation, reagent warming, media preparation, temperature conditioning, materials testing, calibration work, chemical procedures, and other temperature-sensitive laboratory methods.
Its 28 L capacity provides enough working space for larger vessels or multiple samples, making it particularly useful for applications that would quickly overwhelm a small 5 L or 10 L circulating bath.
The circulation system also allows heated fluid to be supplied to compatible external equipment. Potential applications include jacketed vessels, small reaction systems, analytical equipment, heat exchangers, and other apparatus requiring a circulating source of controlled-temperature fluid.
Ideal Laboratory Types
The Fisher Isotemp 3028H is suitable for pharmaceutical and biotechnology laboratories, chemistry facilities, quality-control departments, clinical and life-science research laboratories, industrial R&D facilities, materials-testing laboratories, academic research departments, and other environments requiring dependable heated temperature control.
Its larger bath capacity can be particularly useful for laboratories processing multiple samples simultaneously or working with containers and devices too large for compact circulating baths.
The 3028H can also be a practical choice for laboratories that want one temperature-control system capable of serving both direct immersion and external circulation applications.
Temperature Control & Stability
The Fisher Isotemp 3028H provides an operating temperature range from approximately 15°C above ambient temperature to 150°C with a digital display resolution of 0.1°C.
Active circulation continuously moves heated fluid throughout the reservoir. This promotes efficient heat transfer and helps reduce temperature differences between different areas of the bath, particularly when compared with a basic non-circulating water bath.
The actual minimum operating temperature depends on laboratory ambient temperature. For example, in a laboratory maintained at approximately 22°C, an ambient +15°C specification corresponds to a practical minimum controlled temperature of roughly 37°C.
Because the 3028H is a heating-only circulator, it cannot actively refrigerate the bath. Laboratories requiring temperatures near, at, or below room temperature should consider a refrigerated circulating bath instead.
The 150°C maximum temperature also exceeds the practical operating range of water. Applications above the safe working range of water require an appropriate compatible heat-transfer fluid selected for the intended temperature and laboratory procedure.
Circulation & Pump Performance
The integrated circulation pump is an important advantage of the Fisher Isotemp 3028H. Continuous fluid movement improves heat distribution within the 28 L reservoir and helps maintain more uniform conditions around immersed samples.
The pump can also circulate heated fluid through compatible external equipment, extending the 3028H beyond conventional water-bath applications.
External circulation performance depends on the resistance of the complete fluid loop. Tubing diameter and length, fittings, fluid viscosity, operating temperature, elevation differences, and restrictions within the connected equipment can all affect actual flow.
For applications with specific minimum-flow or pressure requirements, American Instrument Exchange can help verify the configuration and operating performance of the individual unit prior to shipment.
Refurbishment & Testing
This used Fisher Scientific Isotemp 3028H Heated Circulating Water Bath is refurbished and tested by American Instrument Exchange before shipment. Our technicians inspect the heater, circulation pump, temperature controller, display, reservoir, electrical components, safety systems, and fluid connections.
Temperature-controlled equipment is tested using NIST-traceable probes and data loggers. The bath is operated under simulated laboratory conditions to evaluate heating, circulation, temperature regulation, and controller operation. Because this is a large-capacity bath, testing also helps verify that the system can effectively heat and circulate its working fluid.
The reservoir and accessible fluid-contact areas are cleaned and inspected before shipment.
If your application requires operation at a specific temperature or has particular testing requirements, contact American Instrument Exchange before shipment. When practical, our technicians can incorporate customer-requested conditions into final testing.
A 90-day warranty is included with this refurbished Fisher Isotemp circulating bath.
Choosing the Right Heated Circulating Bath
The 3028H is particularly attractive for laboratories that need more working volume than a compact circulating bath. Its 28 L capacity provides considerably more room for samples and vessels while active circulation improves temperature distribution throughout the reservoir.
Bath capacity should be balanced against the application, however. A larger reservoir requires more heat-transfer fluid and generally takes longer to reach a new setpoint than a small bath. Laboratories performing only small-volume procedures may find a compact circulating bath more convenient.
Temperature requirements are equally important. The 3028H is a heating circulator with a minimum temperature approximately 15°C above ambient. It is therefore an excellent choice for elevated-temperature applications but is not appropriate when active cooling is required.
For applications requiring temperatures near or below room temperature, a refrigerated/heated circulating bath would be the better choice.
American Instrument Exchange can help compare available used and refurbished laboratory circulators based on bath capacity, temperature range, circulation requirements, and application.
Related Equipment
American Instrument Exchange stocks a variety of laboratory circulators, including heated circulating baths, refrigerated circulators, immersion circulators, and recirculating chillers. Laboratories considering the Fisher Isotemp 3028H may also want to compare available laboratory water baths, reactors and fermenters, evaporators and extractors, and other refurbished laboratory equipment.
Fisher Isotemp 3028H Frequently Asked Questions
What is the capacity of the Fisher Isotemp 3028H?
The Fisher Isotemp 3028H has a 28 L bath capacity, providing considerably more working space than many compact laboratory circulating baths.
What is the temperature range of the Fisher 3028H?
The 3028H operates from approximately 15°C above ambient temperature to a maximum of 150°C.
Can the Fisher Isotemp 3028H cool samples below room temperature?
No. The 3028H is a heated circulator and does not incorporate active refrigeration. Applications requiring temperatures near or below ambient should use a refrigerated circulating bath.
Can the 3028H circulate fluid through external equipment?
Yes. In addition to circulating fluid within its own bath, the 3028H can supply heated fluid to compatible external equipment.
What is the advantage of a circulating bath over a standard water bath?
A circulating bath actively moves fluid throughout the reservoir rather than relying primarily on natural convection. This can improve heat transfer and temperature uniformity, particularly with larger sample loads.
Can the Fisher Isotemp 3028H operate at 150°C using water?
No. Water is not an appropriate heat-transfer fluid across the entire temperature range of the 3028H. High-temperature applications require a compatible heat-transfer fluid selected for the intended operating temperature.
Is the 3028H suitable for larger samples?
Its 28 L capacity makes the 3028H particularly useful for larger vessels, calibration devices, or multiple samples that would not fit conveniently into a smaller circulating bath.
Does this refurbished Fisher Isotemp 3028H include a warranty?
Yes. This used Fisher Isotemp 3028H is refurbished and tested by American Instrument Exchange and includes a 90-day warranty.
Click Hereto see the Fisher Isotemp 3028H circulator on the American Instrument Exchange 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.
