I have a 2017 Quantum RS 26B with a tankless water heater.
According to manual Pg 15, at this link,
https://girardgroupcompanies.com/sto...24-ENG-694.pdf, you can "Select the desired temperature by adjusting the temperature setting up or down. The UPC settings are from 95 to 124. The unit will maintain the set temperature"
Mine does not will not maintain the set temperature. If I adjust it to 95, the indicator shows 95 for a second or two, then quickly rises to its maximum instead or remaining at 95, and the water is scorching hot.