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$506.50The Story
The Biasi Antares 25C is Biasi's flagship wall-hung condensing combi boiler, delivering 25 kW of heating and instantaneous domestic hot water output. Manufactured at Biasi's advanced Italian facility — where every unit is individually tested before leaving the production line — the Antares represents the pinnacle of the Biasi domestic boiler family. It features a 1:10 modulation ratio, a fully plastic-free brass hydraulic group, Grundfos ErP-rated circulating pump, Adaptive Gas Technology (NG / LPG / 20% Hydrogen Ready), and a large multifunctional touch-sensitive display. This pack pairs the boiler with the Biasi Horizontal Flue Kit (Ø 60/100 mm) for a standard wall-exit installation. The Antares 25C carries an ErP Energy Class A rating as standard — upgradable to A+ with the optional iControl weather-compensation system — and is backed by a 9-year warranty when registered within 30 days of installation — extendable to 10 years with a Biasi magnetic filter or Pro-Fit accreditation.
With a 1:10 turn-down ratio, the Antares can operate at as little as 1/10th of its maximum output — ideal for well-insulated properties and underfloor heating systems with very low heat loss. Reduced cycling, quieter operation, and a longer boiler life are the direct benefits of this wide modulation range.
The eGarc electronic combustion management system continuously reads the flame signal and adjusts gas valve and fan output to maintain optimum CO₂ levels. One model covers Natural Gas, LPG, and up to 20% hydrogen blends — no hardware changes required for gas-type conversion.
The Antares uses a fully brass hydraulic unit — replacing the plastic components found in older designs. Brass is completely recyclable, more durable under pressure cycling, and significantly reduces the risk of stress fractures over the boiler's working life. This is a key differentiator versus many competitor models.
The seamless single-coil primary heat exchanger in stainless steel AISI 441 offers high-temperature strength combined with superior corrosion resistance. Its large oval-section geometry promotes constant water flow, prevents debris accumulation, reduces friction losses, and makes flushing easy. The coil count is sized to the boiler output (10.5 coils for the 25C).
The Grundfos UPM4 7.5 m head ErP pump uses PWM technology to generate precisely the correct flow for prevailing demand. Features include an integrated air purge, built-in drain tap, and manual pump unlock — simplifying commissioning and servicing. High performance combined with low standby consumption meets current EuP/ErP requirements.
The large backlit LCD touch interface simultaneously displays live system pressure, DHW set temperature, CH set temperature, and primary circuit temperature. The touch-sensitive control buttons navigate Summer/Winter/Off modes, DHW and CH adjustment, and the full programming menu including Chimney Sweep, Calibration, Fault History, and the annual service reminder countdown.
The Antares is supplied as standard with a Clapet non-return valve in the flue circuit, enabling simplified connection to pressurised collective flue systems in accordance with UNI 7129. The damper opens automatically under fan pressure during operation and closes at rest to prevent back-flow of combustion products in shared flue scenarios.
The 10-litre expansion vessel (cold pre-charge 1 bar) accommodates systems up to 124 litres total water content, covering the majority of domestic heating installations without the need for an additional external vessel. The vessel is side-mounted and easily accessible for re-pressurisation or replacement during service.
The Antares achieves ErP Energy Class A as supplied and A+ when paired with the optional iControl weather-compensation kit (advanced control + external probe + WFC01 app). Wi-Fi connectivity via the Biasi App enables remote temperature control, real-time monitoring, and instant fault-code notification.
Technical Specifications — Biasi Antares 25C
| Nominal heat input — heating / DHW | 21.0 / 26.0 kW |
| Minimum heat input — heating / DHW | 2.6 / 2.6 kW |
| Max usable power 60°/80°C (heating / DHW) | 20.7 / 25.6 kW |
| Min usable power 60°/80°C | 2.5 / 2.5 kW |
| Max usable power 30°/50°C (condensing) | 22.8 / 28.2 kW |
| Min usable power 30°/50°C | 2.7 / 2.7 kW |
| Efficiency nom. 60°/80°C | 98.5 % |
| Efficiency nom. 30°/50°C | 108.7 % |
| Efficiency at 30% load (30°/50°C) | 109.9 % |
| ErP seasonal efficiency ηs | 94 % |
| DHW flow rate ΔT 25K / ΔT 35K | 15.4 / 10.7 L/min |
| Specific DHW flow rate ΔT 30K (EN 625) | 12.9 L/min |
| Min / Max DHW temperature | 30 / 60 °C |
| Min / Max DHW pressure | 0.5 / 10.0 bar |
| Min / Max CH temperature | 25 / 85 °C |
| Min / Max CH pressure | 0.3 / 3.0 bar |
| Available pump head (at 1000 L/h) | 350 mbar |
| Expansion vessel capacity | 10 litres (pre-charge 1 bar, max system 124 L) |
| NOx class / weighted NOx | Class 6 / 42 mg/kWh |
| Modulation ratio | 1:10 |
| Pump model | Grundfos UPM4 (7.5 m head, ErP) |
| Voltage / power at nominal input | 230 V~ / 94 W |
| Stand-by power draw | 4 W |
| Ingress protection | IPX5D |
| Max coaxial flue length Ø 60/100 mm | 10 m |
| Max coaxial flue length Ø 80/125 mm | 12 m |
| Max twin flue length Ø 80+80 mm | 40 m |
| Compatible flue configurations | C13, C33, C43/C53/C83/C93, B23P, C63 |
| Dimensions H × W × D | 700 × 400 × 300 mm |
| Weight | 31.5 kg |
| Water content | 2.0 litres |
| Gas type | Natural Gas G20 / LPG G31 / 20% H₂ blend |
| Warranty | 9 years (registered within 30 days); 10 years with Biasi magnetic filter or Pro-Fit accreditation |
Frequently Asked Questions
What makes the Antares different from the Biasi Dina?
How do I qualify for the 10-year warranty?
Is the Antares suitable for underfloor heating systems?
What fault codes does the Antares display and can I read them remotely?
Can the Antares connect to a third-party smart thermostat?
What is the automatic calibration (CAF) function?
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Description
The Biasi Antares 25C is Biasi's flagship wall-hung condensing combi boiler, delivering 25 kW of heating and instantaneous domestic hot water output. Manufactured at Biasi's advanced Italian facility — where every unit is individually tested before leaving the production line — the Antares represents the pinnacle of the Biasi domestic boiler family. It features a 1:10 modulation ratio, a fully plastic-free brass hydraulic group, Grundfos ErP-rated circulating pump, Adaptive Gas Technology (NG / LPG / 20% Hydrogen Ready), and a large multifunctional touch-sensitive display. This pack pairs the boiler with the Biasi Horizontal Flue Kit (Ø 60/100 mm) for a standard wall-exit installation. The Antares 25C carries an ErP Energy Class A rating as standard — upgradable to A+ with the optional iControl weather-compensation system — and is backed by a 9-year warranty when registered within 30 days of installation — extendable to 10 years with a Biasi magnetic filter or Pro-Fit accreditation.
With a 1:10 turn-down ratio, the Antares can operate at as little as 1/10th of its maximum output — ideal for well-insulated properties and underfloor heating systems with very low heat loss. Reduced cycling, quieter operation, and a longer boiler life are the direct benefits of this wide modulation range.
The eGarc electronic combustion management system continuously reads the flame signal and adjusts gas valve and fan output to maintain optimum CO₂ levels. One model covers Natural Gas, LPG, and up to 20% hydrogen blends — no hardware changes required for gas-type conversion.
The Antares uses a fully brass hydraulic unit — replacing the plastic components found in older designs. Brass is completely recyclable, more durable under pressure cycling, and significantly reduces the risk of stress fractures over the boiler's working life. This is a key differentiator versus many competitor models.
The seamless single-coil primary heat exchanger in stainless steel AISI 441 offers high-temperature strength combined with superior corrosion resistance. Its large oval-section geometry promotes constant water flow, prevents debris accumulation, reduces friction losses, and makes flushing easy. The coil count is sized to the boiler output (10.5 coils for the 25C).
The Grundfos UPM4 7.5 m head ErP pump uses PWM technology to generate precisely the correct flow for prevailing demand. Features include an integrated air purge, built-in drain tap, and manual pump unlock — simplifying commissioning and servicing. High performance combined with low standby consumption meets current EuP/ErP requirements.
The large backlit LCD touch interface simultaneously displays live system pressure, DHW set temperature, CH set temperature, and primary circuit temperature. The touch-sensitive control buttons navigate Summer/Winter/Off modes, DHW and CH adjustment, and the full programming menu including Chimney Sweep, Calibration, Fault History, and the annual service reminder countdown.
The Antares is supplied as standard with a Clapet non-return valve in the flue circuit, enabling simplified connection to pressurised collective flue systems in accordance with UNI 7129. The damper opens automatically under fan pressure during operation and closes at rest to prevent back-flow of combustion products in shared flue scenarios.
The 10-litre expansion vessel (cold pre-charge 1 bar) accommodates systems up to 124 litres total water content, covering the majority of domestic heating installations without the need for an additional external vessel. The vessel is side-mounted and easily accessible for re-pressurisation or replacement during service.
The Antares achieves ErP Energy Class A as supplied and A+ when paired with the optional iControl weather-compensation kit (advanced control + external probe + WFC01 app). Wi-Fi connectivity via the Biasi App enables remote temperature control, real-time monitoring, and instant fault-code notification.
Technical Specifications — Biasi Antares 25C
| Nominal heat input — heating / DHW | 21.0 / 26.0 kW |
| Minimum heat input — heating / DHW | 2.6 / 2.6 kW |
| Max usable power 60°/80°C (heating / DHW) | 20.7 / 25.6 kW |
| Min usable power 60°/80°C | 2.5 / 2.5 kW |
| Max usable power 30°/50°C (condensing) | 22.8 / 28.2 kW |
| Min usable power 30°/50°C | 2.7 / 2.7 kW |
| Efficiency nom. 60°/80°C | 98.5 % |
| Efficiency nom. 30°/50°C | 108.7 % |
| Efficiency at 30% load (30°/50°C) | 109.9 % |
| ErP seasonal efficiency ηs | 94 % |
| DHW flow rate ΔT 25K / ΔT 35K | 15.4 / 10.7 L/min |
| Specific DHW flow rate ΔT 30K (EN 625) | 12.9 L/min |
| Min / Max DHW temperature | 30 / 60 °C |
| Min / Max DHW pressure | 0.5 / 10.0 bar |
| Min / Max CH temperature | 25 / 85 °C |
| Min / Max CH pressure | 0.3 / 3.0 bar |
| Available pump head (at 1000 L/h) | 350 mbar |
| Expansion vessel capacity | 10 litres (pre-charge 1 bar, max system 124 L) |
| NOx class / weighted NOx | Class 6 / 42 mg/kWh |
| Modulation ratio | 1:10 |
| Pump model | Grundfos UPM4 (7.5 m head, ErP) |
| Voltage / power at nominal input | 230 V~ / 94 W |
| Stand-by power draw | 4 W |
| Ingress protection | IPX5D |
| Max coaxial flue length Ø 60/100 mm | 10 m |
| Max coaxial flue length Ø 80/125 mm | 12 m |
| Max twin flue length Ø 80+80 mm | 40 m |
| Compatible flue configurations | C13, C33, C43/C53/C83/C93, B23P, C63 |
| Dimensions H × W × D | 700 × 400 × 300 mm |
| Weight | 31.5 kg |
| Water content | 2.0 litres |
| Gas type | Natural Gas G20 / LPG G31 / 20% H₂ blend |
| Warranty | 9 years (registered within 30 days); 10 years with Biasi magnetic filter or Pro-Fit accreditation |
Frequently Asked Questions
