SPECIAL OPERATING PRECAUTIONS

TM 5-3895-374-24-2 SPECIAL OPERATING PRECAUTIONS CAUTION 1: BY-PASS VALVE A by-pass valve is provided to allow circulation through the heater and heat exchanger and prevent damage to the heater, when the burner is operated with external valves closed. The by-pass system is controlled by the valve under the heat exchanger (stack end). Be sure this valve is open when operating. CAUTION 2: WATER IN OIL SYSTEM Upon initial start-up or after the heater has been idle during the winter season, the following precautions should be taken to prevent the generation of steam from any water or condensation in the hot oil system. The heater temperature control should be set at 205F. The heater should be operated at this temperature for at least three hours. If the circulating pump pressure remains steady at 15 psi. or higher, then the temperature may be increased 5F at a time, allowing ample time for the entire system to rise to this higher temperature, with a steady pump pressure before going to the next higher temperature. If steam should be generated in the system, indicated by abrupt wide fluctuations or a zero pump pressure and/or a rumbling noise in the heater, stop the burner immediately. Allow enough time for the system to stabilize and the circulating pump pressure to become steady. Removal of the moisture in the complete oil system is time consuming and may require a full day to be done properly and safely, but it is important because steam may cause severe damage to equipment. Note the pump pressure switch will shut off burner any time the pump pressure drops below 10 psi. CAUTION 3: HOT WET WELLS The temperature control thermocouple, high limit switch, pump pressure switch, and thermometers are immersed in the heat transfer fluid. Do not attempt to remove these components when the heater is hot without first draining the hot oil below the level of component to be removed. CAUTION 4: BURNER FUEL PUMP On combination gas/oil burners, be sure there is fuel oil supplied to the fuel pump even when the burner is operating on gas. This is because the pump depends on an adequate fuel oil supply for lubrication. The pump may be disconnected for extended periods of gas firing to reduce pump wear, or to operate the burner when no oil is available to circulate through the pump for proper lubrication. Also in case of pump malfunction, or failure, the coupling should be disconnected for continued operation of the burner on gas. The fuel pump must be removed on the side of the burner housing to gain access to the pump coupling. The fuel lines must first be disconnected from the fuel pump. Next, the fuel pump mounting bolts must be removed so that the fuel pump may be taken out of the burner housing. The pump coupling is a hardened rubber type with female splines on both ends. The coupling can be removed after the pump is removed from the housing by pulling it off the male splines at both the blower motor and pump shaft ends. (page 3 - 939)