eta PelletsCompact 20-32 kW, Operation

Page: 64 / 76

64 www.eta.co.at
[External heat source] function block ETAtouch controller
5.8 [External heat source] function
block
Overview of external heat sources (additional heat
producer)
1 Operating condition and information.
A description of the operating conditions can be
found in the integrated Help menu by pressing the
button.
2 Temperature of the ETA boiler
3 Temperature of external heat source
4 External heat source consumer.
Currently, the consumer is charged by the external
heating at a flow temperature of 54 °C.
How the external heat source works
"External heat source" refers to an additional non-
automatic heat producer in the heating system. This is
often a fireplace or wood chip boiler which cannot be
requested by the ETAtouch control system, but not an
oil or gas burner.
This can work in several ways, depending on how the
additional heat producer was installed:
• External heat source with diverter valve:
The boiler or the external heat source supplies
heat to the consumers. Switching between the ETA
boiler and the external heat source is achieved via
a diverter valve.
With the configurable parameter [Enable diverter
valve], you can set the minimum temperature for
switchover between the ETA boiler and the
external heat source. See chapter
5.8.1.2 "Enable
diverter valve" .
If the temperature of the external heat source is
below this minimum temperature [Enable diverter
valve], the diverter valve switches to the ETA
boiler, which then supplies heat. If this temperature
is exceeded, the valve switches to the external
heat source.
• External heat source with charging pump:
The external heat source features a separate
pump and can simultaneously convey heat to the
buffer together with the boiler.
The charging pump starts up when the external
heat source has exceeded the minimum
temperature [Enable temperature]. In addition, the
temperature of the external heat source must be
higher than the temperature of the charging tank,
plus the difference [Thermostat diff.]. These
parameters are configurable, see chapter
5.8.1.3
"Enable temperature" and 5.8.1.4 "Thermostat
diff."
If the external heat source exceeds the configu-
rable [Switch off boiler at] temperature, the ETA
boiler is switched to [Locked] mode, see chapter
5.8.1.1 "Switch off boiler at" .