The new Bosch Tronic 3000T ES2.5 & ES4 thermostat features a new sensing probe that is attached to the thermostat and inserts into the cavity of the new heating element so the heater can adjust temperatures quicker and maintain a more consistent heat. The thermostat has an adjustment knob accessible from the outside of the unit on the front cover. The temperature adjustment knob for the older models was located under the oval cover on the front of the unit.
The part number for the thermostat is 7738002302 and will work for the wholesale model ES2.5 & ES4 mini tank water heaters. This thermostat will also work for the retail model Ariston GL2.5S & GL4S as well as the older Ariston Pro Ti GL2.5TiS and Ariston Pro Ti GL4TiS mini-tank electric water heaters.
The new thermostat will NOT work for any of the older Ariston GL2.5/GL4/GL2.5Ti or the GL4Ti electric mini-tank water heaters.