A heat source or system of commonly connected heat sources shall be protected by a water-temperature-activated operating control to stop heat output of the heat source where the system water reaches a pre-set operating temperature.
Radiant floor heating panels shall be protected with a high-limit control set 20°F (11°C) above the maximum design water temperature for the panel to prevent the introduction of heat into the panel. The high-limit setting shall not exceed the temperature rating for the pipe and shall be equipped with a manual reset.
A steam heat source or system of commonly connected steam heat sources shall be protected by a pressure-actuated control to shut off the fuel supply where the system pressure reaches a pre-set operating pressure.
A primary water-level control shall be installed on a steam heat source to control the water level in the heat source. The control shall be installed in accordance with the manufacturer's installation instructions.
An air-temperature-sensing device shall be installed in the occupied space to regulate the operation of the heat-distribution system.
Where a minimum return-water temperature to the heat source is specified, the heating system shall be designed and installed to ensure that the minimum return-water temperature is maintained during the normal operation of the heat source.