HOTflow TM model CTM was developed to pre-heat diesel and gas engines for stationary land power, marine and construction equipment. HOTSTART’s CTM HOTflow TM heating system is a complete coolant preheater. It features an integrated pump that combines the benefits of forced circulation with a compact design that can mount to a variety of small engine applications. The CTM model heats engines up to 20L displacement. Forced circulation of the coolant delivers uniform heating throughout the entire engine, extends element life and offers a significant reduction in electrical consumption.