Take the little rod out of the tempering valve and see what happens. You can usually do that by turning off the water and removing the part where the adjustment is located. That, plus cranking up the temperature setting, should solve the problem.

I really like my "second stage" electric (see my earlier post on 3/7 on this thread). I did the plumbing and electric myself so it only cost about $60 more than the price of the water heater at HD. It uses no electricity in the winter, and in the summer the electricity costs less than it costs to keep the boiler hot with expensive oil.