The forced draft burners used on double helical coil units and the atmospheric burners on straight tube units are selected to provide the required input for the fuel(s) to be used. Flame Safety Honeywell Rm-7800 id the standard Circulating Pump Thermal fluid duty MP Pumps are the standard circulating pumps for Phoenix systems.The MP pump provides performance and lift unmatched by other pumps designed for thermal fluid duty. A standby circulating pump can be added to allow operation of the system while pump repairs and maintenance are performed.