ST – 480
- see Section III.g). The pump will turn off below this temperature (minus a
hysteresis of 2°C).
II.9.b)
Boiler tank priority
In this mode, the boiler tank (hot water) pump will be switched on first to run
until the set-point temperature is reached (see Section II.e), after which the
pump will be turned off and the CH circulating pump will be enabled.
The central heating pump will run all the time until the boiler tank temperature
drops below its set-point by the hot water hysteresis value. At that moment the
CH pump will turn off and the HW pump will turn on (both pumps operating
alternately).
In this mode the fan and the feeder are run only up to 62
O
C as measured at the
boiler (instantaneous set-point) so as to prevent overheating of the boiler.
NOTE:
The boiler must be fitted with check valves on the central heating and
hot water pump circuits. The valve mounted on the hot water pump is to
prevent drawing hot water from the boiler tank.
II.9.c)
Pumps in parallel
In this mode both pumps begin to run together (in parallel) above the pump
activation temperature. However, these temperatures may vary for each pump,
depending on your settings (see Sections III.g-h). When this is so one of the
pumps will switch on earlier than the other one, but after both thresholds are
crossed both pumps will run together. The central heating pump will run all the
time while the hot water pump will turn off when the boiler tank set-point
temperature is reached. It will turn on again when the temperature drops by
the preset HW hysteresis value below its set-point.
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