DHW indicates there is a demand for heat on the boiler from the DHW circuit, the pump is powered on, and the supply sensor temperature is too high for the boiler to ignite. This occurs because the water temperature measured by the supply sensor is higher than the tank temperature – ignition diff setting.
This message will stay present until the water temperature measured by the supply sensor is less than the BOILER SUPPLY – boiler supply differential (5ºF) or DHW SETPOINT is satisfied and no longer calls for heat.
