8
OPERATION
CH and DHW required.
The boiler will re and supply heat to the radiators but will give
priority to DHW on demand.
If required the DHW preheat will operate as described on page
17 MENU OPERATION - Preheat, during periods when there
is no call for CH.
DHW only required.
Either set the heating control knob (G) to off - or,
Set the CH external controls to OFF.
Only if pre-heat is selected the boiler will re periodically for
a few seconds to maintain the DHW calorier in a pre-heated
condition. The average time period between firing is 90
minutes. This may vary considerably due to the surrounding
ambient temperature of the boiler.
The boiler will re whenever there is a demand for DHW.
The boiler preheat facility can be immobilised by selecting
preheat OFF (see page 17 MENU OPERATION - Preheat). This
will stop the boiler operating periodically for short periods. This
facility is primarily provided for boiler installations in a sensitive
area (i.e. bedroom etc.).
Note. If the pump and diverter valve have not operated in
the last 24 hours they will run briey to ensure they do not
become seized.
CONTROL OF WATER TEMPERATURE
Domestic Hot Water
The DHW temperature is limited by the boiler controls to
65oC maximum at low draw-off rate, adjustable via the DHW
temperature control (H).
Due to system variations and seasonal temperature uctuations
DHW ow rates/temperature rise will vary, requiring adjustment
at the draw off tap : the lower the rate the higher the
temperature, and vice versa.
Approx. hot water temperatures for the boiler thermostat
settings are:
Knob Setting Flow Temperature
Minimum 40ºC (104ºF)
Maximum 65ºC (149ºF)
Central Heating
The boiler controls the central heating radiator temperature
to a maximum of 80oC, adjustable via the CH temperature
control (G).
WEATHER COMPENSATION
When the Weather Compensation option is tted to the system
then the CH Temperature Control (G) becomes a method of
controlling room temperature. Turn the knob clockwise to
increase room temperature and anti-clockwise to decrease
room temperature. Once the desired setting has been
achieved, leave the knob in this position and the system will
automatically achieve the desired room temperature for all
outside weather conditions.