Atag BC100124, Appliance Technical Manual

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Combi boiler CH mode
CH controls
With a demand from the heating controls after DHW demand, the boiler activates its 1 minute delay period. This is to
prevent the heat exchanger from losing its heat too quickly in the event of a hot water demand.
Then the pump starts and after 30 seconds the gradient control becomes active and the boiler fires up. The starting
point of the gradient control is the currently existing flow temperature. A Delta-T control (25K) ensures a stable control
according to heat request.
If the flow temperature is below the T-set value of 20°C the boiler will immediately start.
If during a demand from the heating the burner switches off, because the desired flow temperature is exceeded, there
will be an anti-cycle time in operation for 5 minutes.
This means that the burner switches on again after 5 minutes if there is still a demand from the heating.
Combi boiler DHW mode
DHW controls (combination boilers)
If a hot water tap is opened the flow sensor measures (F1) the amount drawn off.
Depending on the desired DHW temperature and volume the controls will calculate an output. This realises the desired
water temperature in an efficient way. The hot water sensor (T3) will adjust any minor deviations caused by temperature
fluctuations so that even under these circumstances the desired temperature is constant.
System & regular boiler central heating mode
CH controls
With a demand from the heating controls, the boiler activates its 1 minute delay period. This is to prevent the heat
exchanger from losing its heat too quickly in the event of a hot water demand.
Then the pump starts and after 30 seconds the gradient control becomes active and the boiler fires up. The starting
point of the gradient control is the currently existing flow temperature. A Delta-T control (25K) ensures a stable control
according to heat request.
If the flow temperature is below the T-set value of 20°C the boiler will immediately start.
If during a demand from the heating the burner switches off, because the desired flow temperature is exceeded, there
will be an anti-cycle time in operation for 5 minutes.
This means that the burner switches on again after 5 minutes if there is still a demand from the heating.
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