120*F Inlet Capability For All GE and Hotpoint Models
Was around 1983 IIRC.
BOL plastisol and BOL Hotpoints up until early 1980s had only about a 10-15 minute heated main wash, which was then extended to a 20-30 minute main wash in 1983.
MOL models prior to 1983 had a "Potscrubber" feature which extended the heated main wash by about 15-20 minutes enough to give good heating and wash results at 120*F IMO despite the manual calling for 140*F.
Some TOL models prior to 1983 also had a thermostat that would hold the timer during the main wash until the thermostat was satisfied.
In 1983 all BOL models came with a 30 minute heated main wash, and all MOL and TOL came with with a thermostat and cycle extender that could extend the main wash past 15 minutes if needed.
Around the mid 90s GE began dropping all the thermostats and cycle extenders for fixed 30-56 minute main washes regardless of the cycle selected or inlet temperature.
For example, when I had a new GE DW installed in 2011, the heated main wash was 47 minutes long for all cycles, despite the machine only having a 1.2 gallon water charge in the main wash.
120*F made for some hot water, and 150*F inlet easily got it near boiling. I can confirm this is indeed the key to scrubbing pots.
Today sadly the heater in most dishwasher cutouts as soon 105-140*F is reached. So, no new machine today is capable of scrubbing pots
