Turn off and disconnect all sources of 110-volt AC power. Turn off your propane tank gas valve.
Remove your old heater and switches from their mounting brackets and panels. Mount your new heater in place of your old one; there is no change in the dimensions between models of heater so you do not need to modify any mounting hardware.
Run sufficient lengths of electrical cable from each of the two terminals at the back of the new water heater to your 110-volt AC power source. Ground the installation to the frame of your RV with a copper grounding wire.
Connect the 12-volt ignition terminals to your fuse or circuit breaker board according to the owner's manual for your RV.
Choose a convenient location for mounting the new combo switch. Measure the distance between the location and your water heater, and cut four lengths of electrical cable that are sufficient to reach the heater from your switch location. Strip the insulation on the cable as necessary.
Connect each cable from each switch terminal to the correspondingly colored terminal inside your water heater. The terminal colors are white, blue, orange and green, with green being the ground. Make sure the provided red jumper wire is connected between the top terminals of the left (electric) and right (gas) switch mechanisms.
Reconnect your gas supply and open your gas valve. Turn your electrical power supply back on. Test the switch and make sure your heater is operating properly before you permanently mount the switch to your RV wall panel. Check your wiring or consult your heater's owner manual if you have any difficulties starting and operating the water heater during your test.
