Rendamax E8.1121, Operating Instructions Manual, Page: 30 / 44

Operation
General function description
30
Heat circuit control
Weather-dependent control
The heat generator or flow temperature
is determined via the set heat slope to
suit the measured outside temperature
in such a way that the set value for the
room is approximately set if the heating
system is configured correctly.
=> Exact setting of the heat slope is
extremely important for weather-
dependent control.
The circulation pump is controlled
weather-dependently. The circulation
pump is switched on if there is a
heating demand and in Frost-protection
mode.
Room sensor influence
The current room temperature can be
included in computation of the required
flow temperature via a present room
temperature sensor.
The influence factor (parameter list)
can be set between 0 (fully weather-
dependent regulation) and 20 (room
temperature regulation with minimal
outdoor temperature influence).
Position "----" deactivates room
temperature control. Positions "----"
and "0" indicate differences for
demand-dependent circulation pump
control.
Hot water generation
The programmed hot water
temperature is stabilised by switching
the hot-water cylinder charging pump
and the burner. Storage tank charging
starts when the storage tank
temperature drops below the
temperature setting by 5K. Storage
tank charging stops when the
temperature setting is reached.
Frost protection function
The frost protection circuit prevents the
heating system from freezing by
automatically switching heating
operation on.
Outdoor sensor frost protection
If the measured outside temperature
drops below the set frost protection
temperature the room temperature
setting is set to 5°C for the relevant
heating circuit. The heating circuit is
enabled:
-
the pumps are switched on
- the heat request is sent to the heat
generator
"----“ => outdoor sensor frost protection
deactivated
The function stops when the outside
temperature increases to 1K above the
frost protection temperature setting.
Heat generator frost protection
The heat generator frost protection is
activated when the heat generator
temperature drops below 5°C. The heat
generator is switched on until the heat
generator temperature exceeds the
"MINIMUM HEAT GENERATOR
TEMPERATURE“.
Flow or storage tank sensor frost
protection
The sensor frost protection is activated
when the flow or storage tank
temperature drops below 7°C. Only the
relevant pump is switched on.
The sensor frost protection is
deactivated when the flow or storage
tank temperature increases to above
9°C.
Frost protection via room sensor
If the room temperature drops below
5°C the frost protection function is
activated.
The room temperature setting for the
relevant heating circuit is set to 5°C.
The heating circuit is enabled:
-
the pumps are switched on
- the heat request is sent to the heat
generator
EEPROM check
Every 10 minutes, a check is conducted
automatically in order to establish
whether the settings of the controller
lie within the specified limits. If a value
is found to be out-of-range, it is
substituted by the related default value.
The range transgression is indicated
by the blinking
E
and the error
number 81.
In this case, the user should check the
important settings of the controller. The
warning symbol is cleared after the unit
is restarted (RESET).
Delayed pump switch-off
In the case of switch-off of the
circulation pumps, the circulation
pumps are not switched off until
5 minutes later if one of the burners
was on during the last 5 minutes before
the switch-off instant.
Pump blocking protection
The controller effectively prevents
blocking of the pumps if they are not
switched on for long periods. The
integrated protection function switches
on all pumps which have not been in
operation during the past 24 hours for
5 seconds at 12.00 h ours every day.
Mixer motor blocking protection
If the mixer motor has not moved
for 24 hours it is fully opened at
approximately 03:00 hrs. (once only).
The heating circuit pump is switched
off during this time. The maximum flow
temperature is monitored. Cancelled at
maximum flow temperature - 5K.