one cause for a General Alarm:
Symptom:
Power Off,
Power On,
Displays heating up for a long time: like 5min
then: General Alarm.
Cause:
one of the two heaters is bad:
measure resistance across terminals: should be around 50 Ohms.
If Open, or very large resistance: that element is bad.
If both are good: Check the thermostat.
Good luck.
These things are highly complex, and hardly worth fixing..
Harald, January 2016