A chiller assembly shaped for use in a standard electronics rack. The chiller has a low profile, and is capable of being made to occupy less than 5 rack units. The chiller is modular, with subassemblies positioned to allow easy removal for maintenance. The fan and power supply are made as replaceable subassemblies that can be inserted or removed from the front of the unit without any special tools. The pump is made with a magnetically coupled motor, allowing the motor to be easily removed for service or replacement. The motor is also accessible from the front panel of the assembly.