11
6.2 DRAINING THE WATER HEATER
6.2.1 Switch off and disconnect the electrical supply. Turn off the water supply
to the unit.
6.2.2 Open a hot tap to relieve any system pressure. Disconnect the plumbing
connections to the unit and remove (note full weights of units). Empty
unit through the outlet connection.
6.3 DESCALING
6.3.1 Switch off and disconnect the electrical supply, turn off the water supply
to the unit and drain as above.
6.3.2 Remove the terminal cover as previously described. Remove the plastic
disc from the thermostat spindle and the insulating pad from the terminal
housing.
6.3.3 Disconnect the electrical terminations to the thermostat. Disconnect
earth links to the earthing stud.
6.3.4 Remove the element plate assembly by unscrewing the five securing
screws, tapped jacking points are provided. Remove any loose scale
from the container. Carefully clean off any scale from the element and
thermostat pocket. DO NOT clean scale from interior container walls.
6.3.5 Re-fit the element plate assembly using a new sealing gasket. Note
the correct orientation of the element plate by reference to Figure 05.
Rewire the unit with reference to the Figure 04 .
6.3.6
Refit the cover.
6.3.7 Re-commission the unit following the INSTALLATION and
COMMISSIONING instructions.
FIGURE 05: COMPONENT IDENTIFICATION
