This temperature-initiated adaptive defrost control solution is designed to meet pending U.S. Department of Energy (DOE) conservation standards. It uses smart sensing technology to defrost evaporator coils only when needed. 

The Centinel Intelligent Defrost Control System consists of a microprocessor-driven controller, four temperature sensors, and a suction transducer. 

In this troubleshooting situation you are dealing with equipment that has only been in operation for two months. And during that time frame, the customer has complained that at times the box temperature is higher than it should be, but the unit then seems to recover and freeze OK.

Frigesco has been awarded new UK Department of Energy & Climate Change (DECC) funding of £102,000 to develop a flash defrost system for use in air-source heat pumps (ASHPs). Flash defrost can reduce supermarket cooling energy costs by up to 20 percent. Field trials in working supermarkets are currently underway.