MUL
TIPOINT
7
cover. Turn the backing disc over and refit to the knob ensuring the
notch locates with the boss
on
the underside of the cover. Refit the
terminal cover, the thermostat will now be
locked in the “mid-
range” position.
5.10 Setting the “hot” position:
Rotate the thermostat knob to mid way through the hot graduated
range (red graphic). Follow the procedure detailed above, however
in this case the knob should be held in the “hot” position previously
set. When the terminal cover has been refitted the thermostat will be
locked in the “hot” position. This position is recommended when
using the heater in conjunction with a thermostatic blending valve.
6.0 MAINTENANCE - DESCALING
Little maintenance is required, however in hard water areas the unit will
require periodic descaling to ensure efficient operation. To descale the
unit:
6.1
Switch off and disconnect the electrical supply. Turn off the water
supply to the unit.
6.2
Open a hot tap to relieve any system pressure. Disconnect the
plumbing connections to the unit and remove from the wall bracket
(note full weights of units). Empty unit through the outlet connec-
tion.
6.3
Remove the terminal cover by using a large flat bladed screwdriver to
depress the 3 snap lugs located in the top 3 rectangular depressions.
6.4
Remove the plastic disc from the thermostat spindle. Remove the
insulating pad from the terminal housing. Disconnect the electrical
terminations to the thermostat. Disconnect earth links to the earthing
stud.
6.5
Remove the element plate assembly by unscrewing the five securing
screws, a tapped jacking point is 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.
6.6
Re-assemble the element plate assembly fitting a new sealing gasket.
Note the correct orientation of the element plate by reference to
Diagram 5 overleaf. Rewire the unit with reference to the Wiring
Diagrams. Refit the insulating pad and plastic disc to ensure the
correct operation of the thermostat.
6.7
Re-commission the unit following the INSTALLATION and COM-
MISSIONING instructions.
