2012 Rockwood 8288ws just purchased. When I turn the switch on for the water heater it cycles trying to ignite gas. I want to run electric only. What am I doing wrong?

If Suburban water heater electric element on rocker switch is outside under water heater panel usually with a safety clip pin stopping the switch from being turned on accidentally! Just pull the pin and turn the switch on then when using gas put the pin back in and turn on gas and igniter switch

It could actually be the thermostat, the circuit board, the sail switch, but no way of knowing without actually seeing and diagnosing it.

check that there is gas in the bottle , the tap is on
check that there is power to the relight system

This might not be much help, without more details, but there should be a valve inside the water heater panel (outside) you can open. Open the valve at the main propane tank also.

Make sure the water tank is FULL before you fire it up. There should be a switch inside the coach somewhere to turn it on.

If it doesn't ignite immediately, you probably have air in the lines. Light the stove and let it burn for a minute, then try the hot water tank again. Might take a few tries to get it fired up.

If the water heater is dual fuel (elec/LP) and it is manufactured by Suburban you will need to go outside to the access door of the water heater. Once you have opened the access door to the lower left below and behind the gas valve/burner tube you will see a small black switch labeled on/off. Switch that to on for electric operation. and then you may turn off the LP switch located inside the unit. If it is an Atwood then inside the unit you should have a switch panel with two switches, one for LP and the other for electric. The panel may be by itself or the switches may be located on your tank level monitor panel.

Contact your local service center directly or online here:
http://www.trailmanor.com/contact/contact.html

Contact the manufacturer of the coach for their owner's manual. However, each appliance will have a separate owner's manual form its perspective manufacturer, i.e., Water Heater = Suburban, A/C = Dometic, Refrigerator = Norcold, etc.. There will not be a diagram of electrical or plumbing as a majority of the RV manufacturers do not publish that information. The only thing that I can think of that would cause the TV to reset when the Air Conditioner comes on is if the AC is remote controlled you may have a frequency conflict. It is not typical for the AC to share an electrical circuit with the TV but if that is the case here then the TV may be getting shut down because the AC is drawing too many amps on startup for the TV to continue to function. Turn the breaker off to the AC and see if the TV shuts down also. If it does then you will need to get the issue corrected.

One that has flame on it is for auto ignition on gas. Lightning bolt is for hydro .

You can switch it out but pretty labor intensive. You cannot just add a gas option to the unit. You will have to replace it with a gas heater and then plumb it to the tanks. The existing unit probably has something simple like a safety sensor that went bad or a heating coil.

Sounds like the element in the tank is shorting to ground thru the water in the tank. Disconnect power, the remove cables from element connection and protect them from contacting anything. Turn on breaker again. If it does not trip replace element or entire tank. If it continues to trip it's somewhere in the harness or a bad breaker.