Depends on whether the element is a one piece element or whether its segmented into 2 or 3 parts.
With 2 or 3 part elements an electrician could remove the "bridges" (that bridge the elements together to give the full 15 amps), thereby reducing to 10 or 7.5 amps.
If it is a 2 part element, dont bother as 7.5 is not good enough on a commercial machine with large boiler.
Therefore depends on brand / model machine & type of element fitted....and if it were me, *I wouldnt bother.
Also, a waste of time & money paying a sparkie to deliver you a 15 amp circuit in the house just to run this. Its really the wrong kind of machine for household use and remember, commercial machines work better when used as intended. When not used enough, thats when problems arise particularly from the point of view correct extraction. Machines that "idle" a lot overheat etc etc etc.
Save the bickies and buy the right machine for you instead which if I may say so, will be a machine that can be plugged into a normal household powerpoint & work properly as intended straight off.