Thanks for getting back so quick.
I can see by running the cmk --debug --checks=printer_supply -vvn with this printer is does give the correct information but not on the web page:
Supply ADF Pickup Roller HP Z7Y64A OK - 99% (warn/crit at 10% / 5%)
Supply ADF Separation Roller HP Z7Y66A OK - 97% (warn/crit at 10% / 5%)
Supply Black Cartridge HP W9014MC OK - 46% (warn/crit at 10% / 5%)
Supply Black Developer Unit HP Z8W52A OK - 63% (warn/crit at 10% / 5%)
Supply Black Drum HP W9015MC OK - 99% (warn/crit at 10% / 5%)
Supply Fuser Kit HP 110V-Z7Y75A 220V-Z7Y76A OK - 46% (warn/crit at 10% / 5%)
Is there something I have to change to make the output correct?