omniclave blowing fuse

First rule to keep in  mind - sterilizers and GFCI's never play well together so I might suggest seeing if you can get this off of a GFCI circuit. My thought on the OCR is it sounds to me like you may have at least one bad heating element and/or a bad solid state temperature controller.  RPI has the parts you need for this repair.  If you need further technical support feel free to call me (Neil) directly at 818-882-8611 Ext. 127

have localized it further, first of all, I didn't change any way this was plugged in, has been working for years off the same gfi. GFI pops when control knob is switched from fill to sterilize so it must be a function switch, so need to localize which one, thanks

There is a troubleshooting document on the RPI tech support page which should be able to help you - please look at www.rpiparts.com for the guide to maintaining the Pelton & Crane OCR - it should answer many of your questions - if you can't locate it call me and i'll send you a copy

OK will do, thanks for the help, I will call if I don't get anywhere.