Figure 21. Install the controller box grounding wire to the boiler. Red arrow shows its
position
6)
Reinstall the protecting panel for the pump and the back panel to its original position.
D. Installation in the Top Compartment.
1)
Install the RTD sensor. The RTD sensor should sit in the same place as the original brew
thermostat was located (indicated by the blue arrow in Fig 18). Remove the brew
thermostat by loose the screws that hold it. Insert the RTD sensor to the same bracket that
was used to hold the brew thermostat. Sometimes, it is convenient to work on the screws
by temporarily removing the cable connector on the left side terminal of the heater (green
arrow on Figure 22b). Please note that if the machine is old and as a result, the plastic
protection guard of the heater connector is brittle, it might break off and leave some
unprotected spots. You need to use a small to medium sized flat head screw driver to
remove the screw. Be very careful to not let it drop into the gap below. If it drops to the
top of the grouphead, it could be a lot of trouble to take it out. A magnetized screw driver
will help. Apply a small amount of silicone heat transfer compound to the bottom of the
RTD sensor before installation. This will ensure a fast and accurate temperature
measurement. Fig 22a shows the RTD has been installed (marked with red arrow).
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