Your 2010 Atwood 6 gal water heater uses 120V AC for electric element AND 12V DC ot control the 120V AC Power
Element is installed in backside of WH Tank....down low under a protective cover
Inside that cover is the 12V DC Relay used to trigger the 120V AC to the element.
Could be bad DC Relay
Could be bad/loose AC wiring to/from DC Relay
Could be bad element