Jura boiler/thermoblock for steam 120V/1200W; Suitable only for Z series. Steam boiler is the smaller of the two boilers/thermoblocks in the machine.
There are two thermoblocks in Jura Z5, Z6, Z7 and Z9 espresso machines. One is for hot water and coffee, and the second is solely for steaming/frothing. All Jura One Touch espresso machines have two independent thermoblocks except for J9.
Before replacing the thermoblock, please check the thermofuse and the heating/thermal sensor. The thermofuse is clamped on to the boiler and is light blue in color. The heating sensor is a green wire that is screwed on to the bottom left side of the thermoblock and is green in color.