25
Minimiser
-
Installation
1.
Some earth wires are omitted for clarity -
ensure proper earth continuity when wiring.
2.
This is a fully controlled system - set the
boiler thermostat to MAXIMUM.
3.
Numbering of thermostat terminals applies
only to the manufacturer mentioned.
42 FROST PROTECTION
41 TWO SPRING CLOSED VALVES - pumped only
LEGEND
b
- blue
bk
- black
br
- brown
r
- red
y
- yellow
w
- white
g/y
- green/yellow
gy
- grey
or
- orange
v
- violet
pk
- pink
INSTALLATION
INST
ALLA
TION
Central heating systems fitted wholly inside the house do not
normally require frost protection as the house acts as a
'storage heater' and can normally be left at least 24 hours
without frost damage.
However, if parts of the pipework run outside the house or if
the boiler will be left off for more than a day or so then a frost
thermostat should be wired into the system. This is usually
done at the programmer, in which case the programmer
selector switches are set to OFF and all other controls MUST
be left in the running position.
The frost thermostat should be sited in a cold place but
where it can sense heat from the system.
Wiring should be as shown, with minimal disturbance to other
wiring of the programmer.
Designation of the terminals will vary but the programmer
and thermostat manufacturers' leaflets will give full details.
Diagram A
shows a double-pole frost thermostat, which
should suffice for all systems which do not use the OFF
terminals of the programmer.
Diagram B
shows a 'changeover' frost thermostat, which will
cover most systems which do use CH OFF. If, however, on
such a system the HW pipework is in an isolated part of the
house a second frost thermostat may be used to protect it. If
in doubt ask your installer for advice.
Note.
If the boiler is installed in a garage it may be
necessary to fit a pipe thermostat.
