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• Function of each operating mode:
Operating Mode
Function
On
Continuously on
Once
On for 1 period a day, from Program 1 ON to Program 3 OFF
Auto
Automatic program control
Off
Continuously off
• Fully Pumped and Controlled System (P). Central Heating and Hot Water can be operated
independently.
• Gravity-fed Hot Water System (G). Central Heating cannot be operated without Hot Water.
Central Heating (CH)
Selectable mode for Hot Water (HW)
On
On
Once
On, Once
Auto
On, Once, Auto
Off
On, Once, Auto, Off
In a poorly controlled gravity circulation hot water system, whenever the boiler comes on to
service the heating, there will inevitably be some circulation though the hot water storage
tank, which will then heat up.
Therefore, whenever the HEATING is ON, the HOT WATER is also ON. It is therefore NOT
possible to have independent programmes for heating and hot water hence both CH and HW
are programmed together.
If you have this type of installation (gravity circulation hot water circuit WITHOUT a hot water
control valve), your installer must restrict the Programmer to being a Gravity-fed hot water
system (G).
