Provided by boiler vendor.
Heating supply water temperature is evaluated compared to expected control setpoint temperature using standard reset schedule.
Heating loop supply and return heating water temperature difference is continuously evaluated for excessively high temperature differences.
Boiler supply water temperature is evaluated for running higher than expected compared the standard reset schedule.
Fan operation is evaluated with fan enable command and fan actual operation for expected running.
Room space temperatures are evaluated, using return air temperature, compared to upper and lower limits normally expected for reasonable environmental comfort.