Depends on which brand WH
Suburban
Could be bad electric element
Could be tripped AC circuit breaker for element
Could be tripped High Temp T-stat for electric element
Could be bad set of t-stats for electric element
Atwood
Could be bad element
Could be tripped AC circuit breaker for electric element
Could be bad 12V DC circuit/fuse or relay (used to activate AC power for element)
Won't be t-stats as same set used for electric and propane
Which Brand do you have?
ON EDIT:
See you have a Suburban SW10DE, have had this issue since 2/14/15.
SO.......
Did you check anything as suggested in other post---3 months ago?
Previous post......same problem
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31