i have a natural gas waterheater can i use propane on it

Yes, it is possible to convert from natural gas to propane and vice verse, as long as your water heater is designed to work on both gases and is done by the professional.

Since natural gas and propane, LP, water heaters are working with different gas pressure, the conversion involves changing the gas orifice on the pilot assembly and gas burner and gas regulator.

Every water heater manufacturer provides the approved conversion kit with a new water heater. You can find on the label of the water heater what is the type of gas it is designed for.