Shopping from Canada? 
Go to Defender Canada!
Isotherm
Isotherm 2501 Compact Classic Air Cooled Refrigeration Component System - U200X000R11111AB
Item: #870765 | Part Number: U200X000R11111AB$1,139.60
Description
- Refrigerator or freezer use with fan-cooled compressor design
- Pre-charged, split-system for easy installation with quick-connect lines
- Compact footprint suitable for bulkhead or deck mounting
- Designed for marine use with efficient 12/24V DC Danfoss compressor
Isotherm 2501 Compact Classic Air Cooled Refrigeration Component System - U200X000R11111AB Item # 870765
Description
The Isotherm Compact Classic Model 2501 is an air cooled refrigeration system that can cool as a refrigerator or as a freezer. The maximum freezer capacity is 2.3 cu.ft. and the maximum refrigerator capacity is 7.1 cu.ft.. It's a fan-cooled compressor unit designed for simple installation in existing top or side-loaded refrigerator boxes. All Isotherm Compact Systems come complete and pre-charged. Each system is rated to refrigerate or freeze a specific volume so there's no guessing what will work best for your boat.
Features:
- Refrigerator or freezer use
- Fan-air cooled compressor, electronics and refrigerant
- 12 / 24V DC Danfoss compressor
- To simplify the installation, the system is split into two sections:
- Compressor/condenser unit
- Evaporator
- Easy to install with pre-charged system, "Click-on" bracket and quick connect lines
- Compact footprint, no special plumbing required - can mount on deck or bulkhead
- Be sure to mount air-cooled compressors in a location that will not trap heat in a closed compartment or in an area will get hot (such as an engine room)
- It is important that the compressor compartment is well ventilated allowing cool air to enter from below and hot air to escape at the top
- To archive good operating results, the following is essential:
- Use polyurethane or similar foam
- 30 mm (1 1/4") thick for 50 liter (1.8 cu.ft.) boxes
- 50 mm (2") for boxes up to 80 liter (2.8 cu.ft.) boxes
- 100 mm (4") or more for larger boxes
- Battery capacity should be at least of 75 Ah to enable sufficient power to be stored during engine operation
- All the electrical power supply equipment such as alternator, regulator, cables, connectors and batteries must be kept in good condition
- Use polyurethane or similar foam
- Maximum freezer capacity of 2.3 cu.ft. and maximum refrigerator capacity of 7.1 cu.ft.
- The Isotherm warranty is 2 years from the date of purchase on all components and a 5 year limited warranty on the compressor
Specifications:
- Maximum box volume: 7.1 cu. ft
- Evaporator: Large-O
- Dimensions:
- Evaporator: 10.6" H x 15 W x 5.5" D
- Compressor: 6" H x 6" W x 12" D
- Power consumption (at 12V): Start-up, 3.5A; average, 0.9A
- Weight: 20 lbs
- Danfoss compressor: Model BD50F
Part Numbers for Isotherm 2501 Compact Classic Air Cooled Refrigeration Component System - U200X000R11111AB
Reviews
Rated 5 out of
5
by
murmur from
Isotherm 2501 Fridge
Wow! Way smaller and lighter than my previous unit (Adler/Barbour) and COLD! Very easy to install with the pre-charged lines, and super quiet! Had to visually inspect to make sure it was even on! One caveat, the bottom plate of the 'icebox' is the bottom that is unattached and appears that it could easily break; so had to support separately. But otherwise, gets so cold we can make ice, which was not our intention. Am thinking the similar, smaller unit would have been just as good for our needs.
Date published: 2026-06-01
Rated 4 out of
5
by
Dave H from
Good replacement refrigeration unit for sailboat
The refrigeration unit was easy to install and works well after adding a higher volume cooling fan to keep the condenser from overheating and shutting down.
Date published: 2026-04-07
Rated 2 out of
5
by
s/v Frabjous Day from
No support after sale
Bought and installed Isotherm 2501 (compressor and evaporator for fridge) into my sailboat. Unit worked for 2.5 weeks and stopped chilling. Defender would not help me with replacement rather saying warranty was with distributor. They ignor my calls. I am left with a defective product sold to me by Defender Marine. They said they would call distributor but never followed through. What a horrible way to treat a customer. I am left to fend for myself...
Date published: 2026-01-08
Rated 1 out of
5
by
Anonymous from
Does NOT cool
I installed per instructions and at start up my intial amp draw was 3.4 amps at 12 volts and I was happy. After 3 days my fridge settled in at 36 degrees via a wireless thermometer so I bought food and a bag of ice to put in zip lock bags to help prevent losing too much cold and then I could reuse the cold water. Temp immediately started rising, by morning my fridge was in the 60's, 2.8 amp draw and all my food was going to waste. Turned it off as College was starting so I worked on it the next weekend. PUlls the same initial 3.4 amps at start up then drops to around 2.8 and never gets cold. I bought it with my college disbursement money so I could bring left overs instead of eating out. I spoke with ISOTHERM and they have no idea and were supposed to email me after talking to the techs but that was over a week ago and I have received nothing. At this point I either want my money back or a new unit expedited out. I am currently in the Marine Engineering department in college and am working to get my ABYC Marine Electricians Cert at the end of this half of the semester. So I am quite versed in what I am doing. Adding to that 30 years as a technecian in the OIl Field.
Date published: 2025-09-08
Rated 4 out of
5
by
Jordan R. from
Good Init Overall
Unit works well. Evaporator door should have a hinge. The condensing unit mount is difficult to use-Practice using it before installing it in a tight space.
Date published: 2025-09-02
Rated 4 out of
5
by
Bill from
Isotherm 2501
Easy to install. Cools quickly in refrigeration area. Unit does freeze water for ice, however, is right at 0C or 32F. Not good for ice cream. Overall very pleased. Power consumption is acceptable on lifepo4 batteries.
Date published: 2024-11-24
Rated 5 out of
5
by
daneTheBob from
As an American, this thing rocks
Like the other guys said, I popped in my soda and it was frigid in 0-60. I love it.
Date published: 2024-04-29
Rated 5 out of
5
by
Richie from
I’d recommend this little unit
Relatively easy install. Efficient and quiet. It’s done a solid job of cooling a 6 cu ft icebox here in New England.
Date published: 2023-07-18
Questions
How long are the tunes with this kit? Need to know if I need the extensions
approx. 14 ".
Date published: 2024-04-02