8
OPERATION
Central Heating and Domestic Hot Water required.
The boiler will fire and supply heat to the radiators but will give
priority to Domestic Hot Water on demand.
If required the Domestic Hot Water preheat will operate as
described on page 17 MENU OPERATION - Preheat, during
periods when there is no call for CH.
Domestic Hot Water only required.
Either set the Central Heating temperature control knob (E)
to ‘boiler off’ - or,
Set the Central Heating external controls to off.
Only if pre-heat is selected the boiler will fire periodically for a
few seconds to maintain the Domestic Hot Water calorifier in
a pre-heated condition. The pre-heat will take place only once
in a 30 minute time interval. This may vary considerably due to
the surrounding ambient temperature of the boiler.
The boiler will fire whenever there is a demand for Domestic
Hot Water.
The boiler preheat facility can be immobilised, refer to page 20.
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 briefly to ensure they do not
become seized.
CONTROL OF WATER TEMPERATURE
Domestic Hot Water
The DHW temperature is limited by the boiler controls to 65
o
C
maximum at low draw-off rate, adjustable via the Domestic Hot
Water temperature control knob (F).
Due to system variations and seasonal temperature fluctuations
DHW flow 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:
Domestic Hot Water Knob Setting
Flow Temp
Minimum
40ºC
Maximum
65ºC
Central Heating
The boiler controls the central heating radiator temperature
to a maximum of 80
o
C, adjustable via the CH temperature
control knob (E).
Central Heating Knob Setting
Flow Temp
Minimum
30ºC
Maximum
80ºC
