Measure the opening where the water heater will be installed. The SW6P requires a wood-framed opening, 12 3/4 inches by 12 3/4 inches square. Make sure the bottom edge of the opening is flush with the RV floor and that there is enough clearance at the rear of the heater for the water connections. Adjust the dimensions of the opening as necessary.
Slide the water heater into the opening, being careful not to damage the control housing mounting flange or the gas and water connections. Have another person inside the RV to help guide the heater if possible. Position the heater so that the control housing is flush with the outside of the RV.
Apply a dab of caulk to each of the screw holes in the bottom and sides of the control housing. Insert wood screws into each of these holes and attach the heater to the wood frame and floor of the RV.
Apply a bead of caulk around the outside of the opening. Caulk the back edge of the water heater door frame as well. Slide the door frame into the control housing. Attach the frame with the three No. 8, 3 1/4-inch screws provided by the manufacturer according to the instructions.
Check the stability of the water heater from inside the RV. Use shims if necessary to ensure it is firmly supported and in position. Wrap plumber's tape around the water line connections on the back of the water heater. Thread the supply line fittings onto the tank connections and tighten.
Remove the grommet from the gas supply line opening in the control housing near the gas valve. Insert the gas line through the opening, being careful not to kink the line. From outside the RV, thread the flare fitting onto the valve and tighten. Install the grommet around the gas line and press it back into the opening in the housing. Caulk around the grommet and gas line to create an air-tight seal.
Mix a drop or two of detergent with water in a small bowl or container. Turn on the gas supply. Check for leaks by applying the detergent solution with a paint brush to all gas connections. If bubbles appear, tighten and check again. Wipe the solution off with a rag when finished.
Turn on the water supply. Open the RV faucets and bleed air from the hot water tank. Close all faucets and check for leaks. Light the hot water heater according to the manufacturer's instructions and check for proper operation.
