It could be your thermal/thermostatic switch. Baka dehins fuse kasi kung busted yung fuse, 'di dapat umaandar yan kasi walang current. Try a "switch-on-and-off' test sa thermostatic switch mo. Kung walang man-yari, baka stuck-closed na yung switch, or, kung may relay yan, naka-permanent "latch" yung relay.