If you need hot water on demand, without a cylinder, without a tank and without waiting for it to heat up, a gas instantaneous water heater is one of the most practical answers there is. The Biasi Multipoint 16S is a wall-mounted, room-sealed 30kW unit that heats water only as you use it, delivering up to 16 litres per minute to several outlets at once.
Open the tap and the water arrives at the temperature you set. No cylinder to heat, no stored water to run out of, and no manual tap-blending mid-shower.
It comes in two versions, natural gas and LPG, which makes it one of the few genuinely flexible options for properties both on and off the mains gas network. In this guide we explain how it works, where it fits best, which model you need, and the one accessory we recommend you order with it. We also cover a separate option for electric-only properties: the Biasi Pro-Electric 14kW combi boiler.
The explainerHow the Biasi Multipoint 16S works
A conventional system stores hot water in a cylinder and keeps it hot until it is needed. The Multipoint takes a different approach: it heats water only at the moment you open a tap. Cold mains water flows through the unit, a fan-assisted burner fires, and the water leaves at your chosen temperature.
What makes the 16S more than a basic on/off heater is its control system. A microcomputer reads three sensors at once: the water flow sensor, the inlet temperature sensor and the outlet temperature sensor. It then adjusts a proportional gas valve in real time to hold your set temperature, even if a second tap opens partway through a draw.
Set anywhere from 35°C to 65°C on the digital LCD touch panel. The unit holds that outlet temperature as flow rate and inlet temperature change.
The last-used temperature is remembered, so the heater is ready at your preferred setting from the first draw after a power cycle.
Normal holds your set temperature. Auto maps the outlet temperature to the measured inlet temperature. Eco modulates gas supply to minimise consumption.
While the hot tap is open, the temperature cannot be raised above 48°C, helping prevent accidental scalds. Nine independent safety systems are built in.
Why 0.2 bar matters
The 16S fires from a minimum inlet pressure of just 0.2 bar and a minimum flow of 2.5 L/min. That is among the lowest activation thresholds for a 30kW instantaneous heater, and it is what makes the unit workable in upper-floor flats, loft conversions, rural properties and other places where mains pressure can be marginal.
Room-sealed, so no extra ventilation
The Multipoint is a type C13/C33 room-sealed, fan-flued appliance. It draws combustion air from outside through the outer duct of a 60/100 mm coaxial flue and expels flue gases through the inner duct. Because it does not take air from the room, it can be installed in a wider range of locations than an open-flued heater.
The headline 16 L/min figure is measured at a 25°C temperature rise. In a typical UK winter, with cold water arriving at around 10°C, the 16S delivers approximately 9.5 L/min at a comfortable 42°C. That is enough for a good-flow shower and a running basin at the same time.
It is worth sizing on this winter figure rather than the headline number. If two bathrooms will regularly run together, or you use a high-volume shower head, the 16S gives more headroom than the smaller 14S (28kW, 14 L/min), which suits one or two bathrooms with normal sequential use.
Applications: homes, commercial kitchens, caravans and shepherd huts
Because there is no cylinder, no cold water tank and no need for a full heating system, the Multipoint suits a much wider range of buildings than you might expect.
Ideal where high or simultaneous hot water demand is the problem. It also works where there is no room for a cylinder, in flats, loft conversions and extensions where mains pressure is modest.
Hand-wash stations, prep sinks and pot-wash areas all need reliable hot water with no recovery time. Continuous supply and back-to-back demand are exactly what an instantaneous heater handles well.
Off-grid or semi-permanent sites often run on LPG. The LPG model gives a static caravan or holiday let genuine mains-pressure-style hot water without a stored tank.
Compact, wall-mounted and cylinder-free, so it suits small footprints. Paired with a bottled or tank LPG supply, it can provide a proper hot shower in a remote spot.
Two things to plan for before you buy. First, the Multipoint needs a 230V mains electrical supply for the fan, ignition, control system and display. It will not run in a power cut, and a switchable fused spur is required. Second, it must be installed by a Gas Safe registered engineer, and it must have its own dedicated flue to an external wall or roof. It cannot connect to a shared or common flue.
For off-grid sites with no mains electricity at all, speak to us before ordering so we can check what will work for your setup.
Natural gas or LPG: the two Multipoint 16S models
Both models are the same 30kW, 16 L/min appliance. The difference is the gas the unit is factory-set for. Choose the one that matches the fuel supply at your property.
Factory-set for natural gas (G20, 20 mbar). The right choice for any property on the mains gas network, from family homes and flats to commercial kitchens.
£390.00 inc. VAT Buy Natural Gas ModelFactory-set for LPG (G30/G31, 29 to 37 mbar). Built for off-grid homes, caravans, static homes, shepherd huts and any site running on bottled or tank propane or butane.
£390.00 inc. VAT Buy LPG ModelCan I convert between gas types? Yes. The unit is certified for both fuel families (gas category II2H3P / II2H3B/P) and can be converted using the appropriate Biasi conversion kit. Conversion is a job for a Gas Safe registered engineer only, and the Benchmark commissioning checklist must be updated afterwards. Never connect a natural gas unit to LPG, or the reverse, without conversion first.
Natural gas vs LPG at a glance
| Feature | Natural Gas model | LPG model |
|---|---|---|
| Factory-set gas | Natural gas (G20, 2H) | LPG (G30 butane / G31 propane) |
| Supply pressure | 20 mbar nominal | 29 to 37 mbar |
| Best for | Mains-gas homes and businesses | Off-grid homes, caravans, huts, rural sites |
| Max flow (25°C rise) | 16 L/min | 16 L/min |
| Nominal heat input | 30 kW | 30 kW |
| Outlet temperature | 35°C to 65°C | 35°C to 65°C |
| Flue | 60/100 mm coaxial | 60/100 mm coaxial |
| Price (inc. VAT) | £390.00 | £390.00 |
The wall mount kit you need: 10999.4111.0
Biasi Multipoint Wall Mount Kit, part number 10999.4111.0. This is the wall mounting kit for the Multipoint 14S and 16S. It comes with the fittings and mounting hardware you need to hang the unit securely, and we recommend ordering it with every Multipoint.
On the product page, choose Wall Mount Kit from the Type selector. Prices on that page start from £59.00 inc. VAT.
View Wall Mount KitThe Multipoint must be mounted vertically on a flat, stable surface that can support its weight. Any tilt can cause incomplete combustion. Where the wall is combustible, a non-combustible, heat-resistant mounting board must be fitted first, extending at least 10 mm beyond the unit frame on every side. Keep these clearances to combustible materials: 450 mm above, 50 mm each side, 300 mm below and 350 mm in front.
Don't forget the flue
The flue is not included with the heater. You will need a Multipoint-specific 60/100 mm coaxial flue kit. These parts are not interchangeable with Biasi condensing boiler flue accessories, even though the diameter is the same, because the Multipoint runs at flue gas temperatures up to 118°C. All the flue options are on the same accessories page.
| Accessory | Part number | Use |
|---|---|---|
| Wall Mount Kit | 10999.4111.0 | Hangs the unit on the wall |
| Horizontal Flue Kit | 10999.1398.0 | Direct through-wall exit |
| Vertical Flue Kit | 10999.1405.0 | Roof exit |
| Vertical Connection Adapter | 10999.1399.0 | First piece at the unit on vertical routes |
| 1 m Flue Extension | 10999.0149.0 | Extends the run |
| 90° Flue Elbow | 10999.0152.0 | Changes direction by 90° |
| 45° Flue Elbow | 10999.0153.0 | Gentler change of direction |
No gas at all? The Biasi Pro-Electric 14kW combi boiler
The Multipoint gives you hot water only. If you need heating and hot water from a single unit, and you have no gas supply (or would rather not have one), the Biasi Pro-Electric 14kW Single Phase Combi Boiler covers both jobs from electricity alone.
Wall-mounted electric combi with no flue, no gas and no condensate drain. Modulates from 2 to 14 kW, delivers up to 7 L/min of hot water, and comes with a 3-year warranty.
£1,095.00 inc. VAT Buy Electric CombiNo combustion means no flue route and no gas safety risk. Site it in any room where the electrical supply can reach, such as a kitchen, airing cupboard or utility room.
It uses the same ¾" heating and ½" hot water connection sizes as a conventional gas combi, so it can drop into existing pipework and radiators.
A dedicated floor heating mode limits flow temperature to 60°C, protecting underfloor circuits. Radiator mode goes up to 80°C.
A 24-period timer makes it easy to run heating and hot water during cheap-rate or self-generated electricity periods.
Is it right for your property?
The single-phase 14kW model suits flats, apartments and 1 to 2 bedroom properties with one bathroom. At 7 L/min it can supply one shower at a time. Running two showers together would exceed its capacity, so for multi-bathroom homes with simultaneous demand a stored hot water system is a better fit.
Electrical requirements. At full load the boiler draws 61A. It needs a dedicated circuit with at least 10 mm² cable and an 80A MCB/ELCB, installed by a Part P registered electrician who will issue a certificate. Many older properties will need a consumer unit or incoming supply upgrade, so check this before you order.
Add the fittings pack
Biasi's installation literature shows full-bore isolation valves and an automatic bypass valve in the recommended system schematic, and the plumber's checklist asks the installer to confirm a bypass valve has been fitted. The optional Biasi Pro-Electric Combi Boiler Fittings Pack (Ei1124503) gathers the brass valves, copper tails and unions to make those connections, so the boiler can be isolated for servicing.
Brass isolation valves, copper tails and bend, union nuts and sealing washers, designed around the Pro-Electric combi's connections. Sold separately from the boiler.
£77.00 inc. VAT Buy Fittings PackOne more warranty point: Biasi's manual also requires a magnetic filter on the heating return, and states that failing to fit one will affect your warranty. The fittings pack does not include a filter, so add one separately.
Control it with the Drayton Lifestyle RFPT
The boiler accepts a standard 2-wire on/off demand signal at its room thermostat input, so it works with conventional wired thermostats. The Drayton Lifestyle RFPT is a straightforward way to add proper room temperature and schedule control: a wireless, battery-powered thermostat paired with an included mains SCR receiver that outputs a volt-free switch signal.
7-day schedule with up to 6 switching periods a day, 5 to 35°C range, 30 m typical wireless range, and the SCR receiver included in the box. Batteries not included.
£63.00 inc. VAT Buy ThermostatBecause the thermostat is wireless, you can position it where it senses the room best without running cable. The SCR receiver is mains-connected, so it must be wired by a competent person to current wiring regulations.
The full electric combi bundle
| Component | Role | Price (inc. VAT) |
|---|---|---|
| Biasi Pro-Electric 14kW Combi Boiler | Heating and hot water | £1,095.00 |
| Biasi Fittings Pack (Ei1124503) | Isolation valves, tails and unions | £77.00 |
| Drayton Lifestyle RFPT (THD22120) | Wireless room thermostat with receiver | £63.00 |
Which Biasi solution is right for you?
| Question | Multipoint 16S | Pro-Electric 14kW |
|---|---|---|
| What does it provide? | Hot water only | Heating and hot water |
| Energy source | Natural gas or LPG (plus 230V supply) | Electricity only |
| Hot water flow | Up to 16 L/min (25°C rise) | Up to 7 L/min (30°C rise) |
| Flue needed? | Yes, 60/100 mm coaxial | No flue |
| Installer | Gas Safe registered engineer | Part P registered electrician |
| Best for | Homes with high or simultaneous demand, kitchens, caravans, huts | Flats and 1 to 2 bed homes with no gas |
| Price (inc. VAT) | £390.00 | £1,095.00 |
Frequently asked questions
Does the Multipoint 16S work in a power cut?
No. It needs 230V mains power for the microcomputer control system, the DC fan, the electronic ignition and the display. With no power there is no fan, no ignition and no combustion. If your property has frequent interruptions, discuss options with your installer and Biasi before specifying.
Should I choose the 16S or the 14S?
The 14S (28kW, 14 L/min) suits a 1 to 2 bathroom property with one outlet in use at a time. The 16S (30kW, 16 L/min) gives about 14% more flow and is the better choice for two bathrooms used together, a large-volume shower head, or a busy kitchen alongside a bathroom.
Is the flue included with the heater?
No. The flue is sold separately. You need a Multipoint-specific 60/100 mm coaxial kit: horizontal for a through-wall exit, or vertical for a roof exit. Extensions and elbows are available for longer or more complex routes.
How do I register the 2-year guarantee?
Call Biasi UK on 01922 714600 within 30 days of purchase, with your installer's Gas Safe details to hand. The guarantee covers manufacturing defects where the unit was installed and commissioned to the manual and the Benchmark checklist was completed.
Can the Pro-Electric 14kW run underfloor heating?
Yes. A floor heating mode limits the flow temperature to 60°C to protect underfloor circuits. Switch between radiator mode (up to 80°C) and floor heating mode on the touchscreen.
Does the Drayton RFPT replace my programmer?
It replaces the room thermostat function. The SCR receiver is wired in place of the existing room thermostat connection, and the RFPT then controls room temperature. It also has its own 7-day schedule. The boiler's touchscreen additionally has a 24-period timer.
Tell us about your property, your fuel supply and your hot water demand, and our team will point you to the right Biasi solution, with a free, fast quote.
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