diode testing

HI everyone. The microwave in my advantium stopped heating. Upon inspection I removed the diode and discovered it read open with my ohm meter in both directions. I am a liscenced electrician so I know how to discharge the capacitor. My problem is the new diode WB27X10330 reads the same as the one I was replacing. Do I have a bad replacement diode or am I missing something here. Thanks in advance.

Check out this link for complete instructions on HV diode testing. http://www.gallawa.com/microtech/diode.html