Zanussi zwf16581w turns off after 5 mins use err R74?

Hi my zanussi zwf16581w blew its power inlet plug fuse 13amp, I replaced the fuse the machine powered up and then into its cycle it blew again, after research I replaced the heating element turned the machine on and now it does not blow the main fuse, but 5 mins into a normal cycle the machine switches itself off, I can turn the machine on it will drain and spin but will not get past the heating stage of any cycle. More research done i have done a reset/diagnostic mode when turning the programme selector knob to delicates error E74 is displayed (heating circuit) having checked the element again and got 27 ohms across the terminals decided that this is ok, have blown down pressure switch tube no blockages where do I go from here.. The machine is a good 6 years old and we live in a hard water area should I just call it a day and replace the machine.... Help as the misses is pestering me to get it fixed.
Richard.