Mark GS+ 35 Technisches Handbuch Seite 7

The boiler siphon must connect to the odour trap siphon in the drainage system to the sewer via
EN
an open connection. Make sure that the siphon is protected against frost (risk of freezing).
3.0 Controls
The modulating heater can be controlled in various ways.
0-10 volt DC
A 0-10 volt DC controller passes a signal to the air heater. If the signal is greater than 2 volts DC,
the air heater will start to operate. If the signal remains below 1 volt DC, the air heater switches
off. The speed of the combustion air fan and consequently the burner load are controlled linearly
between 2 and 10 volts DC. When the signal lies between 1 and 2 volts DC, the combustion air
fan speed is continually set to minimum. A link must be placed across terminals A and B (230 VAC)
for continuous ventilation. A 0-10 volt DC signal must be connected using two-core shielded mains
cable for low-power use. Make sure polarity is correct. (Applicable in combination with an optional
modulating EC axial fan.)
OpenTherm
An OpenTherm thermostat measures the prevailing room temperature, the target room
temperature and the current air discharge temperature. This data is used to determine the target air
discharge temperature. The microprocessor built into the air heater adjusts the burner capacity until
the target air discharge temperature is achieved. An OpenTherm thermostat must be connected
using a shielded 'twisted-pair' two-core cable for low power use. The polarity is unimportant. The
OpenTherm thermostat provided by the manufacturer allows the burner controls to be unlocked
at the thermostat. This thermostat also displays operating and fault codes, see chapter 7 Faults.
Switching on continuous ventilation is possible with this thermostat. (Not applicable in combination
with an optional modulating EC axial fan.)
230 volt AC thermostat
The heater can be switched on and off via a 230 volt AC thermostat. The thermostat must be
connected to terminals 1 and 2 and a jumper must placed across terminals A and C; refer also to the
electrical diagram. When heat is demanded, the appliance will ramp up to maximum load in stages.
(Not applicable in combination with an optional modulating EC axial fan.)
On/off control
If a conventional on/off control arrangement is used, the room thermostat operates independently.
The thermostat measures the room temperature via a built-in sensor and compares the reading
to the set temperature. In this on/off control arrangement, communication only takes place in one
direction: i.e. from the thermostat to the air heater. (Not applicable in combination with an optional
modulating EC axial fan.)
4.0 Start-up/shutdown
4.1 General
Before being packed, each appliance is fully tested for safety and correct operation. Among other
checks, the gas pressure and CO2 are set. You must however always check the gas pre-pressure.
Never turn the adjusment screws without good cause. Do not forget to instruct the user on the
proper use and operation of the appliance and peripherals.
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