15
2.
TECHNICAL FEATURES AND DIMENSIONS
2.1.
Technical features
This boiler has a built-in multi-gas atmospheric burner.
All versions come with electronic ignition, an ionization flame and an AQUA PREMIUM system for the production of DHW, with a 25-
litre stratification storage tank and a secondary plate heat exchanger.
The following versions are available:
BTN 24
a natural-draught open-flue boiler for CH and DHW, heat output 23.31 kW
BTFS 24 a forced-draught balanced-flue boiler for CH and DHW, heat output 23.8 kW
BTFS 28 a forced-draught balanced-flue boiler for CH and DHW, heat output 28.4 kW)
BTFS 32 a forced-draught balanced-flue boiler for CH and DHW, heat output 31.3 kW
These boilers meet all the requirements in the country of destination indicated on the rating plate.
Installation in a different country may cause a hazard for people, animals and property.
The main technical features of the boiler are given below.
Construction characteristics
• IPX4D electrically protected control panel
• Electronic safety board and integrated modulation
• Electronic ignition with separate igniter and ionization flame
detector
• Stainless steel multi-gas atmospheric burner
• Modulating double-shutter gas valve
• High output monothermal copper heat exchanger
• DHW stainless steel plate heat exchanger
• 25-litre vertical stratification storage tank with magnesium
anode
• Motorized switching valve
• 3-speed CH pump with built-in deaerator
• DHW pump
• 8-litre CH expansion vessel (models BTN 24 and BTFS 24) and
10-litre expansion vessel (models BTFS 28 and BTFS 32)
• 2-litre DHW expansion vessel
• Combustion fan (BTFS)
• Low-water pressure switch
• DHW priority flow switch
• DHW filter
• Adjustable bypass
• Boiler filling and drain cocks
• DHW, CH and storage tank temperature probes
• Safety limit thermostat
• Flue gas thermostat (BTN)
• Differential pressure switch (BTFS)
• 3-bar CH safety valve
• 6-bar DHW safety valve
User interface
• Liquid crystal display showing the boiler operating status
• Mode selector: RESET, OFF, WINTER, SUMMER and ANTI-FREEZE
• CH water temperature regulator: 35-78°C
• DHW water temperature regulator: 35-57°C (also used to
(de)activate the AQUA PREMIUM system)
• Water pressure gauge
Operating features •
• CH electronic flame modulation with timer-controlled rising
ramp (50 seconds)
• DHW electronic flame modulation
• DHW priority function
• CH anti-freeze function (ON 5°C; OFF 30°C or after 15 minutes
of operation)
• DHW anti-freeze function (ON 5°C; OFF 10°C or after 15 minutes
of operation)
• Storage tank anti-freeze function (ON 5°C; OFF 10°C or after 15
minutes of operation)
• Anti-legionella function
• Timer-controlled chimney-sweep function (15 minutes)
• Ignition flame propagation function
• CH maximum heat input adjusting trimmer
• Ignition heat input adjusting trimmer
• Timer-controlled room thermostat (240 seconds with CH flow
temperature >40°C)
• Heating pump post-circulation function in CH, ANTI-FREEZE
and CHIMNEY-SWEEP mode (180 seconds)
• Heating pump post-circulation function in DHW mode (6
seconds, only with selector 2 on WINTER)
• Post-circulation function for heating temperature >85°C (30
seconds).
• Post-ventilation safety function (ON 95°C; OFF 90°C).
• Anti-blocking function for CH pump, DHW pump, switching
valve and 2-way valve (6-second operation every 24 hours of
boiler inactivity)
• Ready for connection to a room thermostat (optional)
• Ready for operation with an external probe (optional, supplied
by the manufacturer)
• Ready for operation with an OpenTherm remote control
(optional, supplied by the manufacturer)
