jon,
those thermax machines are pretty decent (actual build) but can be a bear to do work on cause may parts are proprietary! at least thats how they use to be. that may have changed over the years!!!
most of them come with very small heating elements too. they're not designed to heat water to boiling, or make water hot for that matter. the purpose of the lil heater is to warm up the solution water, with cleaning agent already in solution water, to make it work better. as most everyone knows, the warmer water is, the better cleaning can be obtained!
weak vacuums, lame heaters, etc......