Noma digital block heater timer # stopped working and has a flashing C on the
Screen. What does this mean it is not in the instructions?

This maybe helpful. As near a I can tell its a set timer prompt. (Or RESET the timer)

http://www.ccixpress.com/cci/Marketing/Woods_Canada_Timer_Instructions/49122.pdf

Was the unit unplugged, or did you experience a power outage? Microwaves and digital alarm clocks do the same thing after being unplugged or power goes out even for a short time. Was this your experience with other devices or appliances?