The Biasi RinNova Adaptive 30S System Boiler is a wall-hung high-efficiency condensing system boiler delivering 30 kW of central heating output. As a system boiler it heats the central heating circuit directly and works alongside a separate hot water cylinder — delivering higher simultaneous hot water flow rates than a combi and eliminating the need for a cold water tank in the loft. The RinNova Adaptive system boiler shares the same compact 700 × 400 × 300 mm casing as the combi S-model but with a CH-only hydraulic circuit: there is no diverter valve, no internal plate heat exchanger, and no DHW flowmeter. An optional external cylinder sensor (E07) connects to the PCB to allow the boiler to monitor and control cylinder temperature. The boiler features Adaptive Gas Technology for automatic combustion optimisation, a patented mono-spiral stainless steel heat exchanger, a plastic-free brass hydraulic unit, an ErP-rated modulating circulating pump, and a 7-litre integral expansion vessel. It carries an ErP Energy Class A rating — upgradable to A+ with the optional iControl weather-compensation system — and is backed by up to 8 years warranty (subject to Biasi T&Cs). This pack pairs the boiler with the Biasi Horizontal Flue Kit (Ø 60/100 mm, Part No. 10999.0387.1).
108.7%
Condensing Efficiency
Installation — Gas Safe Engineer Required. This appliance must be installed and commissioned by a Gas Safe Registered Engineer in accordance with current Gas Safety (Installation & Use) Regulations, BS 7671, Building Regulations Part L, and the Biasi installation manual. This is a system boiler — it must be connected to a correctly sized and commissioned hot water cylinder. For unvented cylinders a G3-qualified engineer must be involved. Condensate pipe must be run to a suitable drain with freeze protection in exposed locations.
System Boiler — Cylinder and External Controls Required. The RinNova 30S system boiler does not produce domestic hot water directly. A separate unvented or vented hot water cylinder, cylinder thermostat, zone valves (S-plan or Y-plan), and programmer are required for a complete installation. The optional external cylinder NTC probe connects to the E07 terminal on the PCB and allows the boiler to monitor cylinder temperature directly. The boiler's 7-litre integral expansion vessel serves the CH circuit; verify system volume is within its capacity or add an external vessel.
Pack Contents: Biasi RinNova Adaptive 30S System Boiler (M300V.30 SR) + Horizontal Flue Kit (Ø 60/100 mm, Part No. 10999.0387.1). The boiler ships with all isolation valves with pre-formed copper pipes (CH flow Ø22, CH return Ø22, gas Ø22, condensate Ø20), wall mounting plate, paper template, power supply cable, user/installation/service manual, and warranty documentation. *Up to 8-year warranty subject to Biasi T&Cs — visit biasi.co.uk for full terms.
Why a System Boiler?
A system boiler is the right choice where high simultaneous hot water demand is required across multiple bathrooms, or where a cylinder is already installed. Because hot water is stored in a cylinder, several outlets can run at full flow simultaneously — unlike a combi, which is limited by the boiler's instantaneous heat input. The system boiler also eliminates loft cold tanks, reducing pipework and freeze risk.
CH-Only Hydraulic Circuit
The RinNova 30S system boiler has a simplified CH-only hydraulic circuit — no diverter valve, no internal DHW plate exchanger, and no DHW flowmeter are fitted. The hydraulic diagram shows two connections: CH flow and CH return. Hot water production is delegated entirely to the external cylinder, keeping the boiler's internal water path clean, low-resistance, and straightforward to service.
Adaptive Gas Technology (A²GC²)
The Advanced Adaptive Gas Combustion Control system continuously reads the flame signal and adjusts both the gas valve and fan to maintain optimal CO₂ combustion at all times — regardless of changes in gas supply quality. One boiler model covers both Natural Gas (G20) and LPG (G31) with no mechanical conversion parts required; the gas type is selected and calibrated electronically by the engineer during commissioning.
Mono-Spiral Stainless Steel Heat Exchanger
The single-circuit stainless steel primary heat exchanger uses Biasi's patented mono-coil design with no junctions or welds — maintaining high efficiency even when retrofitted to older, less clean systems. Its oval cross-section promotes uniform water flow and self-cleaning circulation, preventing debris accumulation and making power-flushing straightforward at service.
Plastic-Free Brass Hydraulic Unit
The RinNova Adaptive's fully brass hydraulic manifold replaces the plastic assemblies of older designs. Brass handles pressure cycling without fatigue cracking, is completely recyclable, and eliminates a common failure mode in ageing boilers. Combined with cardboard (not polystyrene) packaging, it reflects Biasi's commitment to circular economy principles throughout the product lifecycle.
ErP-Rated Modulating Circulating Pump
The factory-fitted modulating circulating pump (ErP-rated, Class A) circulates water through the primary heat exchanger and CH system, adjusting its speed in response to system demand. Available pump head at 1000 L/h is 320 mbar. Pump modulation percentage is readable in the boiler's Info display — useful during commissioning and when diagnosing low-flow conditions. The pump can be manually unlocked for servicing using a flat-head screwdriver on the central rotor plug.
Digital Control Panel
The backlit LCD control panel displays CH temperature set-point, live system pressure, and operational status. Multi-function keys access Summer/Winter/Off modes, fault diagnostics (fault codes E01–E99 + L1), error history log, annual maintenance countdown, and the full programming menu — including Chimney Sweep (4 levels), Automatic Gas Calibration, and System Deaeration. Remote and external probe wiring accesses via the PCB terminal block.
iControl System / A+ Energy Class
The boiler achieves ErP Energy Class A as standard. Fitting the optional iControl system — comprising an advanced modulating room control, external temperature probe, WFC01 Wi-Fi module, and Biasi Connect App — raises the classification to A+. The probe connects to the external probe terminals on the PCB and allows the boiler to continuously modulate CH flow temperature in response to outdoor conditions, maximising condensing efficiency.
Service Access & Safety Systems
The three-piece removable casing provides quick access to all components. Safety systems include a flue temperature NTC probe and thermal fuse (E10 lockout above threshold), primary circuit pressure switch (E04 below minimum), by-pass valve as standard, and overheat thermostat (E02 lockout). Three automatic reignition attempts are made on ignition failure (E01) before lockout — reducing unnecessary service calls on intermittent ignition issues.
Technical Specifications — Biasi RinNova Adaptive 30S System Boiler (M300V.30 SR)
| General |
| Model designation |
M300V.30 SR |
| G.C. Appliance Number |
41-583-39 |
| Boiler type |
System (CH only — requires separate hot water cylinder) |
| Gas type |
Natural Gas G20 / LPG G31 (electronic selection — no mechanical kit) |
| Heat Input & Output |
| Nominal heat input — CH |
26.0 kW |
| Minimum heat input — CH |
3.8 kW |
| Max usable CH power 60°/80°C |
25.6 kW |
| Min usable CH power 60°/80°C |
3.6 kW |
| Max usable CH power 30°/50°C (condensing) |
28.3 kW |
| Min usable CH power 30°/50°C |
4.0 kW |
| Efficiency |
| Nominal efficiency 60°/80°C |
98.6 % |
| Minimum efficiency 60°/80°C |
94.5 % |
| Nominal efficiency 30°/50°C |
108.7 % |
| Efficiency at 30% load (30°/50°C) |
109.7 % |
| ErP seasonal efficiency ηs |
94 % |
| Energy class |
A standard; A+ with optional iControl system |
| Central Heating Circuit |
| Min / Max CH temperature |
25 / 80 °C |
| Min / Max CH pressure |
0.3 / 3.0 bar |
| Available pump head (at 1000 L/h) |
320 mbar |
| Expansion vessel capacity |
7 litres |
| Domestic hot water |
Via separate external cylinder only |
| Emissions & Electrical |
| NOx class / weighted NOx |
Class 6 / 34 mg/kWh |
| Modulation ratio |
1:9 |
| Circulating pump |
Modulating ErP-rated (Class A) |
| Voltage / power at nominal input |
230 V~ / 96 W |
| Stand-by power draw |
3 W |
| Ingress protection |
IPX5D |
| Flue & Physical |
| Min / Max flue gas temperature |
44 / 78 °C |
| 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 |
| Dimensions H × W × D |
700 × 400 × 300 mm |
| Weight |
36 kg |
| Water content |
2.0 litres |
| CH connections |
Flow Ø22 mm / Return Ø22 mm (with isolation valves) |
| Gas connection |
Ø22 mm |
| Condensate connection |
Ø20 mm |
| Warranty |
Up to 8 years (subject to Biasi T&Cs — see biasi.co.uk) |
Frequently Asked Questions
What is the difference between this system boiler and the RinNova 30S combi?
The RinNova Adaptive 30S System Boiler (model M300V.30 SR) shares the same casing and primary heat exchanger as the combi 30S but has a CH-only hydraulic circuit — no internal plate heat exchanger, no diverter valve, and no DHW flowmeter are fitted. Hot water is produced entirely by a separate external cylinder, which the boiler heats via the primary circuit. The combi version produces DHW instantaneously but is limited to one bathroom drawing at a time; the system version can supply multiple outlets simultaneously from the stored cylinder.
What cylinder size is recommended for a 30 kW system boiler?
A 30 kW system boiler will reheat a 150-litre cylinder in approximately 30 minutes from cold. For a medium to large family home with 2–3 bathrooms, a 180–250 litre cylinder is typically recommended. The cylinder should be sized to the household's peak demand period — consult a CIPHE-qualified engineer or use the CIBSE Guide G sizing tables. For unvented cylinders a G3-qualified engineer must carry out the installation.
What controls and wiring are required with this system boiler?
A complete system requires a programmer/timer, room thermostat, cylinder thermostat, and zone valves wired in an S-plan or Y-plan configuration. The boiler accepts volt-free room thermostat contacts via the remote terminal block. The optional external cylinder NTC probe connects to the E07 terminal on the main PCB, allowing the boiler to directly monitor and control cylinder temperature. Weather compensation is enabled via the external probe terminals.
Does the 7-litre integral expansion vessel cover most domestic systems?
The 7-litre integral expansion vessel (1 bar cold pre-charge) is adequate for many domestic installations. For larger systems — particularly those with extensive pipework, large radiator arrays, or where an unvented cylinder adds significant water volume to the primary circuit — calculate the total system water content and compare against the vessel sizing tables in the installation manual. An additional external expansion vessel can be added in parallel if required.
What fault codes should an engineer be aware of on the RinNova system boiler?
Key fault codes for the system boiler include: E01 (ignition lockout — check electrode, gas supply, gas valve), E02 (safety thermostat lockout — check system pressure and pump), E04 (pump circulation/pressure failure — check pressure and pressure switch), E07 (external cylinder NTC probe fault — check wiring and probe resistance), E10 (flue NTC or thermal fuse lockout — check flue probe resistance 12–14 kΩ at 20°C and thermal fuse continuity), E05 (fan anomaly), and E68/E78 (probable low gas pressure). The error history is accessible by holding keys A and C for 5 seconds until "HiS" appears on the display.
Is system water treatment required at installation?
Yes. Biasi requires the heating system to be thoroughly power-flushed and dosed with a suitable inhibitor before commissioning. A magnetic filter is strongly recommended to protect the heat exchanger and pump — and is a condition of the extended warranty. In hard water areas a scale reducer on the cold mains feed is also advisable. The condensate drain must run to a suitable internal drain point; if exposed pipework is unavoidable, insulate against freezing in accordance with current building regulations.
