Features and technical data
Installation, use and maintenance manual – G gas unit heater
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FEATURES AND TECHNICAL DATA
1.1
FEATURES
1.1.1
Operation
The G series gas unit heater is an independent heating
appliance with airtight combustion circuit and forced air
draft.
It has been designed to be installed inside the room to be
heated.
The combustion circuit is room sealed and meets the re-
quirements for type C appliances: combustion air supply
and flue gas exhaust discharge take place outdoors and
are ensured by the functioning of a blower inserted in the
combustion circuit.
The appliance is also approved for type B for installations
where it is allowed to take the combustion air directly
from the room to be heated.
The gas unit heater operation is controlled by a room
thermostat, integrated in the supplied chronothermostat.
The gas unit heater operates by modulating the heat out-
put and ventilation speed continuously.
Products of gas combustion (natural gas or LPG) flow in-
ternally through the heat exchangers, which are invested
externally by the air current produced by the fan, deliver-
ing warm air flow into the room.
The fan operates automatically only when it receives the
enabling signal from the fan thermostat, i.e. with hot heat
exchangers, in order to avoid the introduction of cold air
into the room, and it will switch off with cold exchangers.
The air flow direction is adjustable vertically by means of
the revolving louvres of the grille.
If heat exchangers overheat due to malfunction, the tem-
perature probe cuts off the power supply to the gas valve
and drives the blower and the fan at maximum speed. If
the temperature should increase further, the limit ther-
mostat trip causes the gas unit heater to switch off.
A blower upline of the burner mixes the air and gas and
expels the combustion fumes.
In the event of obstructions in the intake or exhaust duct,
or in the event of malfunction of the blower, the electron-
ic board will automatically modulate the gas unit heater
heat output. In the event of obstructions or malfunction
beyond the permitted range, the flue thermostat trip
causes the gas valve to stop and the gas unit heater to be
turned off.
The winter operation of the gas unit heater can be auto-
matic or manual.
In summer it is possible to operate the fan only in order to
provide a pleasant air flow within the room.
1.1.2
Mechanical components
▶
Premix stainless steel burner.
▶
High head blower, with rotation speed modulation.
▶
Cylindrical stainless steel combustion chamber.
▶
Robur patented heat exchangers, made out of a spe-
cial aluminium die-cast alloy, with horizontal finning
on the air side and vertical finning on the flue gas ex-
haust side, with a very high heat exchange capacity.
▶
External steel panelling with epoxy powder enamel
finish.
▶
Axial fan(s) with high air flow, with rotation speed var-
iation.
1.1.3
Control and safety devices
▶
Electronic management board, with microprocessor
and noise filter, which provides the following func-
tions:
burner ignition
flame monitoring and modulation
blower management and blower speed control
fan speed control
heat exchanger temperature probe control
minimum flue gas temperature probe control
▶
100 °C limit thermostat with manual reset against heat
exchangers overheating.
▶
Flue thermostat.
▶
Gas solenoid valve.
