The Biasi Multipoint flue accessories range is designed exclusively for the Biasi Multipoint 14S and 16S gas instantaneous water heaters. The Multipoint uses a Ø 60/100 mm coaxial flue system (C13/C33 appliance type) — the same diameter as the Biasi condensing boiler range but with dedicated terminals and connectors specific to the Multipoint. These parts are not interchangeable with the condensing boiler flue accessories. The system must exit through an external wall or roof; the flue cannot be connected to a shared or common flue. All Multipoint flue accessories use push-fit connections with integrated seals. The Multipoint operates as a non-condensing water heater, so flue gas temperatures reach up to 118°C at nominal input — all accessories are rated accordingly.
Installation — Gas Safe Engineer Required. All Multipoint flue components must be installed by a Gas Safe Registered Engineer in accordance with current Gas Safety (Installation & Use) Regulations and the Biasi Multipoint installation manual. The flue must not be connected to a common or shared chimney. The unit must be installed vertically — inclination will cause incomplete combustion. Maximum permitted flue lengths must not be exceeded. Do not mix Multipoint flue parts with condensing boiler flue accessories — part numbers and terminal designs differ.
Flue Length and Elbow Deductions. The Multipoint 14S and 16S are C13/C33 appliance type with a Ø 60/100 mm coaxial flue. Each 90° elbow deducts from the permitted maximum run; each 45° elbow deducts a smaller amount — refer to the Biasi Multipoint installation manual for the specific permitted maximum length for your installation route. The flue gas temperature at nominal input reaches 118°C, which is significantly higher than a condensing boiler — ensure all accessories, wall penetrations, and sealants are rated for this temperature.
Multipoint Flue System Overview. The Biasi Multipoint 14S and 16S connect to the flue via a single coaxial collar at the top of the unit (item 1 in the unit parts diagram). The coaxial system draws combustion air through the outer duct and exhausts flue gases through the inner duct — providing a room-sealed (fan-flued) installation with no requirement for additional room ventilation. A vertical connection adapter (10999.1399.0) is used when the flue must first exit the unit vertically before routing horizontally to the terminal.
Biasi Multipoint Flue Accessories
| Product |
Part No. |
Description |
| Wall Mount Kit |
10999.4111.0 |
Wall mounting kit for the Biasi Multipoint 14S and 16S water heater. Provides the wall fixings, expansion screws, and mounting hardware required to securely hang the Multipoint on the installation wall. The Multipoint must be mounted vertically on a flat, stable surface capable of supporting the unit's weight. When the installation wall is a combustible material, a non-combustible heat-resistant mounting board exceeding the unit frame size by at least 10 mm in all directions must be used — this kit provides the fixing hardware for that board arrangement. Clearance requirements: 450 mm above, 50 mm each side, and 300 mm below the unit must be maintained to combustible materials. The installation template (Figure 5.6–5.8 in the Multipoint manual) shows the two top-hole and two bottom-hole fixing pattern with centres at 180 mm horizontally and 601 mm vertically. |
| Horizontal Flue Kit |
10999.1398.0 |
Complete horizontal flue terminal kit for the Biasi Multipoint 14S and 16S, Ø 60/100 mm coaxial. Designed for a standard direct through-wall exit where the flue exits horizontally through an external wall. Includes the terminal, outer air duct, inner flue pipe, and wall plate with all seals. The Multipoint flue terminal is specific to the Multipoint water heater and must not be substituted with condensing boiler terminals (different part numbers apply). For installations requiring a longer horizontal run, add 1 m extensions (10999.0149.0) and elbows as required, staying within the maximum permitted flue length stated in the installation manual. The flue must slope slightly downward towards the terminal to allow condensate drainage away from the unit. |
| Vertical Flue Kit |
10999.1405.0 |
Complete vertical flue terminal kit for the Biasi Multipoint 14S and 16S, Ø 60/100 mm coaxial. Used for roof-exit installations where a wall exit is not possible or practical. Includes the roof terminal, inner and outer pipes, and seals. An appropriate roof flashing plate must be sourced to suit the specific roof type (pitched or flat) — verify compatibility and roof penetration requirements before installation. For longer vertical runs, 1 m extension pieces (10999.0149.0) and pipe support brackets are required at the intervals specified in the installation manual. The Vertical Connection adapter (10999.1399.0) is used at the boiler collar to transition from the unit's top connection to the vertical flue pipe. |
| Vertical Connection Adapter |
10999.1399.0 |
Vertical flue connection adaptor for the Biasi Multipoint 14S and 16S. Connects the coaxial flue collar at the top of the Multipoint unit to a vertical or angled flue run. This adaptor is the first piece of the flue system at the boiler on a vertical installation, transitioning from the unit's integrated flue collar to the standard 60/100 mm coaxial pipe system. Required on all vertical flue installations and on horizontal runs that route upward before turning horizontally. Supplied with integrated push-fit seal. Note: the Multipoint flue collar connection geometry differs from the condensing boiler range — always use Multipoint-specific adaptor parts. |
| 1 m Flue Extension |
10999.0149.0 |
1 metre coaxial flue extension for the Biasi Multipoint 14S and 16S, Ø 60/100 mm. Used to extend the flue run beyond the length provided in the terminal kit — on either horizontal or vertical routes. Each extension adds 1 m to the total flue run. Combine with 90° elbows (10999.0152.0) and 45° elbows (10999.0153.0) to navigate corners and obstructions. The total extended run must remain within the maximum permitted flue length for the Multipoint as stated in the installation manual. Push-fit connection with integrated seal — no additional sealant or adhesive required. |
| 90° Flue Elbow |
10999.0152.0 |
90° coaxial elbow for the Biasi Multipoint 14S and 16S flue system, Ø 60/100 mm. Changes the direction of the flue run by 90° — used to route the flue around structural obstacles, over ceilings, or to turn from a vertical to a horizontal run. Each 90° elbow deducts from the maximum permitted flue length — refer to the Biasi Multipoint installation manual for the exact deduction value. Push-fit connection with integrated seal. Do not use condensing boiler 90° elbows (e.g. 10999.0390.1) on the Multipoint — Multipoint-specific elbows must be used. |
| 45° Flue Elbow |
10999.0153.0 |
45° coaxial elbow for the Biasi Multipoint 14S and 16S flue system, Ø 60/100 mm. Provides a gentler 45° change of direction — useful for angling the flue gradually away from a wall surface, routing around shallow obstructions, or improving flue aesthetics where a 90° elbow would be intrusive. Each 45° elbow deducts a smaller amount from the maximum permitted flue length than a 90° elbow — refer to the Biasi Multipoint installation manual for the exact deduction value. Two 45° elbows can be used in place of a single 90° elbow where a smoother bend is preferred. Push-fit connection with integrated seal. |
Quick Reference — Multipoint Flue Accessories at a Glance
Wall Mount Kit
10999.4111.0
Horizontal Flue Kit
10999.1398.0
Vertical Flue Kit
10999.1405.0
Vertical Connection
10999.1399.0
1 m Extension
10999.0149.0
Frequently Asked Questions
Can I use Biasi condensing boiler flue accessories on the Multipoint?
No. Although both the condensing boiler range and the Multipoint water heater use a Ø 60/100 mm coaxial flue diameter, the terminal designs, connection geometry, and part numbers are different and not interchangeable. The Multipoint operates at significantly higher flue gas temperatures (up to 118°C) compared to a condensing boiler (typically 40–85°C), and the dedicated Multipoint accessories are designed for these higher temperatures. Always use the Multipoint-specific parts listed above.
Can the Multipoint be connected to a shared or common flue?
No. The Biasi Multipoint installation manual explicitly states that the flue cannot be connected to a common flue. The unit must have its own dedicated sealed flue system exiting directly through an external wall or roof. This is a regulatory requirement under the Gas Safety (Installation & Use) Regulations and Building Regulations Part J.
When do I need the Vertical Connection Adapter (10999.1399.0)?
The Vertical Connection Adapter is required whenever the flue run exits the unit vertically — either on a full vertical (roof-exit) installation, or on an installation where the flue first rises vertically before being redirected horizontally to the wall terminal. It is the first piece of the flue system at the unit collar on these routes. On a direct horizontal wall-exit installation using the Horizontal Flue Kit (10999.1398.0), the connection at the unit is handled by the terminal kit itself and the adapter is not required.
What clearances are required around the Multipoint on a combustible wall?
The Biasi Multipoint installation manual requires the following minimum clearances to combustible materials: 450 mm above the unit, 50 mm each side, 300 mm below, and 350 mm in front. Where the installation wall itself is a combustible material, a non-combustible heat-resistant mounting board extending at least 10 mm beyond the unit frame in all directions must be fitted before the Wall Mount Kit (10999.4111.0) is used. Electric wires and equipment must maintain a minimum 400 mm horizontal clearance from the unit.
Does the Multipoint need additional room ventilation because it is room-sealed?
No. The Biasi Multipoint 14S and 16S are room-sealed (fan-flued) appliances — appliance type C13/C33. Combustion air is drawn from outside through the outer duct of the coaxial flue system, and flue gases are expelled through the inner duct to outside. Because the unit does not draw air from the room, no additional room ventilation is required for the combustion process. Standard room ventilation requirements for habitable spaces still apply in accordance with Building Regulations.
