A steam generator includes a submersible burner compartment with at least one burner subassembly and an associated submersible primary ignition means. The burner subassembly also has an associated infrared primary flame monitoring subassembly. The primary flame monitoring system and primary ignition means are all housed within the burner compartment whereby when the burner compartment is filled with water, the burners are all submerged. The infrared flame monitoring subassembly is electronically coupled to a primary monitoring device and a fuel feed pipe is couple to the burner subassembly. A super heater compartment is coupled to and receives steam exhausted from the burner compartment. The super heater compartment has at least one burner subassembly located therein. An associated submersible secondary ignition means and an associated infrared secondary flame monitoring subassembly are provided for each burner subassembly. The burner, secondary ignition means and infrared secondary monitoring subassembly are all housed within the super heater compartment with the infrared subassembly electronically coupled to a secondary monitoring device.