Abstract: A method (126) and a low capacity controller (28) enable a chiller system (20) to operate below a minimum allowable capacity. The chiller system (20) includes a chiller (40) and a chiller fluid loop (30), having a supply line (36) for conveying a chiller fluid (34) from the chiller (40) and a return line (38) for returning the chiller fluid (34) to the chiller (40). A capacity demand for the chiller (40) is determined. When the capacity demand is less than a minimum allowable capacity of the chiller (40), the chiller fluid (34) is routed from the return line (38) to a heat exchanger (96) of the low capacity controller (28) where the chiller fluid (34) is warmed and returned to the return line (38). The warmed chiller fluid (34) establishes a false capacity demand, detectable at the chiller (40), that is at least the minimum allowable capacity.