7
Weather Compensation Kit -
Installation
CH OPERATION
The On and Off time control of central heating should be
controlled by a separate timer.
During programmed On times the Central Heating Radiator
Flow Temperature is controlled by the boiler relative to the
Outside Temperature as shown in the diagram.
The Room temperature can be adjusted using the Central
Heating Temperature Control Knob on the boiler as follows.
Essentially rotating the knob clockwise increases the room
temperature and rotating the knob anti-clockwise decreases the
room temperature.
The Room Temperature Setpoint in the associated graph is
not directly related to the Actual Room Temperature but is the
Nominal Room Temperature during a programmed CH period.
This can be adjusted between 5 and 30 degrees by the
CH Potentiometer Knob on the Boiler when the Outside
Temperature Sensor is connected. The graph only shows
temperatures between 12 and 30 degrees for clarity.
Examples:
1. If the CH Potentiometer Knob is set to display 22ºC on the
Boiler Display the Room Temperature Setpoint will be 22ºC
and the curve 22 will be followed, indicated by 11th curve
in from the left hand side. So as the outside temperature
varies the Flow Setpoint to the CH circuit will increase and
decrease proportionally.
2. If the CH Potentiometer Knob is rotated fully clockwise, the
Boiler Display will read 30ºC and the Room Temperature
Setpoint will be 30ºC hence the curve 30 will be followed.
3. If the CH Potentiometer Knob is rotated fully anticlockwise,
the Boiler Display will read 5ºC and the Room Temperature
Setpoint will be 5ºC. This is an unrealistic Room
Temperature Setpoint for a CH period during an ON time,
but it is calculated internally for managing Frost Protection
for the system based upon Outside Temperature.
DHW OPERATION
When the system is in a timed on period for DHW and the tank
stat is not satisfied, OV will be generated on the switched live
input SL2 of the boiler.
This will ensure that Weather Compensation adjustment is
ignored at this time. The set point will be fixed at 80 degrees.
The demand is indicated on the display by ‘ON’ and the burner
on symbol as appropriate.
7 WEATHER COMPENSATION KIT OPERATION
FL
O
W
SE
TP
O
IN
T
OUTSIDE TEMPERATURE
ROOM TEMPERATURE SETPOINT
