55
│
5.17.1. DHW request
The Boiler (Burner) function will be activated only when there is an active demand for DHW
heating (the measured DHW temperature has dropped below the currently desired value
following the set DHW temperatures and periods – see menu 5.3.).
5.17.2. HC request
The Boiler (Burner) function will be activated only when there is an active demand for charging
the heating circuit’s thermal store.
The boiler switching is influenced by the time programs and method of switching –
either following a request from DHW or following a request from the heating circuit. In
case both the thermostats (5.17.1. and 5.17.2.) are switched off, the boiler will never
be switched on!
5.17.3. Burner sensor
An optional boiler temperature sensor for switching off the boiler when the max. temperature
is reached (see 5.17.9.).
5.17.4. Delay
Boiler switching delay. If all other switch-on conditions are met, the boiler will switch on after
the period of time set here expires.
5.17.5. Ecomode
A boiler economy mode when heating by a solid fuel boiler or solar collectors is active. This
function can be operated in 2 different variants: Shutdown, when the boiler is completely
switched off, or Decrease. In the Decrease mode, the boiler is switched on only if the
temperature at the optional boiler sensor drops below Teco (5.17.6.).
5.17.6. Decreased temperature for boiler switching (Teco)
The preset switch-on temperature for the boiler when the Decrease option is selected and the
boiler Eco mode is active (see 5.17.5.)
5.17.7. Decreased temperature of heating circuit (HC offset)
The desired HC temperature offset if the Decrease option is selected and the boiler Eco mode
is active (see 5.17.5.).
5.17.9. Max. boiler temperature (Tmax)
Maximum boiler temperature measured by the optional boiler sensor (5.17.3.). If this
temperature at the set sensor is exceeded, the boiler is shut down. The boiler will be started
again when the temperature drops below the value Tmax. Switching off the boiler by the max.
temperature can be disabled by selecting the Off option.
5.17.10. Boiler time program
Time program of the boiler. For each weekday, three time intervals can be specified when the
boiler function is enabled. The boiler can be switched on in these intervals only if the switch-
on request by either DHW or heating circuit is met.
5.17.11. Protection against Legionella
Protective function against Legionella.
The settings are identical with the settings of protective functions for aux. heat sources (see
5.8.10.).
5.22. Return flow increase (return preheating)
The menu is available only if the Return flow increase function is assigned to an
output in menu 7. Special functions.
The return flow increase will be switched on when the difference between the storage sensor
(e.g. thermal store) and the return flow sensor is exceeded.
5.22.1. Max. temperature in storage tank (Tmax)
Max. temperature at the storage sensor (5.22.4.) to stop the return flow increase. If the
storage temperature is above this value, the function remains stopped disregarded of the
other conditions.