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SHT Heiztechnik,
aus Salzburg
Operating instructions
M21/HB M27/GB
Page 6
SHT Heiztechnik aus Salzburg GmbH, A-5020 Salzburg-Bergheim, Rechtes Salzachufer 40 Tel. 0662-450444-0, Fax-DW 9
Our current general terms and conditions apply.Errors, printing faults and technical changes reserved
SAFETY FEATURES
The temperature sensor and oxygen sensor monitor the boiler at each stage of combustion. If the
system is set to "OFF "
by
pressing the
button during operation, the control function will remain in
operation until combustion of the loaded fuel (only at mode “logs” and “working”).
At combustion chamber elevated temperatures and after a power failure, the system is automatically
brought into service in order to avoid uncontrolled combustion (danger of deflagration).
Frost protection criteria (system set to "OFF"):
The
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has an extensive anti-freeze function that protects the complete system against
frost damage.
After the activation of one of the frost protection criteria, the boiler is temporarily started if the system
is set to "OFF"; the display will change to flashing "ON" when preventing frost damage to the system by
starting the pellets burner.
In general, the frost protection function is activated when the outside temperature falls below an
average of -3°C during a 24 hour period. In addition, the following criteria apply:
A) Protection of domestic hot water reservoir:
The boiler starts the pellets burner autonomously if the temperature probe of boiler 1 and/or boiler 2
registers a temperature below 6°C.
After the level for Initial Heating Low Temperature Mode (default setting 35°C) the boiler switches to
"OFF". During this phase, the control device displays "Risk of Frost DOM.WATER burner activated".
B) Protection of heating circuits:
If frost protection function is activated, heating circuits are monitored by cyclically flushing of the heat
circuit pumps for one minute every 20 minutes. During this minute, the control device displays "Pump
ON for 60 sec. for FROST PROTECTION".
If the preliminary temperature falls below 6°C, the pellets burner startsautonomously and runs until the
frost protection criteria are met and switches "OFF" subsequently. During this phase, the control device
displays "Risk of Frost DOM.WATER burner activated".
C) Protection of boiler:
The boiler starts the pellets burner autonomously if the temperature probe of the boiler registers a
temperature below 6°C.
The pellets burner runs until the minimal boiler runtime is reached and switches "OFF" subsequently.
During this phase, the control device displays "Risk of Frost DOM.WATER burner activated".
If the installation is "
∗
OFF", then after activation of one of the three frost protection criteria, the boiler
switches temporarily to "
∗
ON" to avoid frost damage to the installation by starting the pellet burner.
NOTICE: If the combustion operating mode is set to the "SPLIT LOGS ONLY" option, the
automatic frost protection is not activated!
If no or not enough pellets are in place, the frost protection functions mentioned above
cannot be executed!!!
When the power is off or when the boiler is in standby mode, the
burn back monitoring function
(also when in the "SPLIT LOGS ONLY" combustion mode) is active, i.e. the feed auger feeds back the
hot material from the feed channel into the combustion chamber.