If it is a Suburban Brand WH......
There is an ON/OFF switch in outside compartment for the electric element
There is also a separate set of t-stats for the electric and a set for LP. Both have 'reset' buttons in outside compartment (Rubber cover--push to 'Reset') Electric set is on left side. If ECO (high temp t-stat) tripped it will need to be reset for electric to work.
Electric element is feed directly from a 120V AC circuit breaker. Check for tripped CB
If Atwood Brand WH....
Electric and LP use same set of t-stats. So if LP works problem is not with t-stats.
Electric uses 12V DC to activate the 120V AC.
12V DC comes from fuse panel to ON/OFF switch then to a relay (located by element on backside of water heater). When relay makes up....120V AC from a circuit breaker then feeds the element.
SO check DC fuse and AC CB
Suburban uses a 1440W element, Atwood uses a 1400W element.
Both brands on electric can heat 70*F supply water to 130*F/140*F within one hour. Once hot recovery time is roughly 30 mins.