The Pennco KW Series II now features a new Honeywell High Limit and Circulator Relay Control with digital temperature display and diagnostics. In the Less Coil version, the control monitors water temperature and delays the burner starting until any residual heat has been transferred. Thermal purge logic measures rate of temperature change inside the boiler and delays burner firing accordingly. This maximizes efficiency by turning on the burner only when needed. In the With Coil version the Low Limit Control seeks maximum temperature to satisfy domestic hot water call bypassing thermal purge logic.