Elterm Electric System Boiler 4 to 14kW

Description

The Elterm Sergeant (AsBN) electric system boiler is built to heat both radiator or underfloor heating circuits and, when the optional DHW package is fitted, a separate domestic hot water cylinder. In the 4kW to 14kW output band it is well matched to flats, apartments and smaller homes without a mains gas supply, or to properties adding electric heating as a backup to a heat pump.

Built on Elterm's Basic LED automation platform, the boiler is wall-mounted, requires no flue, and includes a built-in expansion vessel, circulation pump and safety valve as standard. Its optional DHW package adds a three-way solenoid valve, cylinder sensor and priority DHW logic, so heating and hot water can run from the same compact unit.

4-14kW

Power range covered

99.5%

Boiler efficiency

Class D

Energy efficiency (A+++ to D scale)

24 months

Manufacturer guarantee

70°C

Max CH operating temperature

PV Ready

4x solar-integration features

Installation & Electrical Safety

Electrical and hydraulic installation, commissioning and servicing must be carried out by a qualified, legally authorised installer, with overcurrent and RCD protection sized to the fuse and cable table below. The manufacturer's 24-month guarantee is void if the boiler is connected or operated incorrectly, or if a boiler protection kit (magnetic filter and water descaler) is not fitted where required by the warranty terms.

Compact, Flue-Free Design

Wall-mounted with no flue or chimney connection required, making it straightforward to fit in flats, utility cupboards or plant rooms without external ventilation work.

PV Ready Functionality

Includes an operation counter, adjustable maximum power lock, voltage-free (0V) contact, and disconnectable contact for cooperating with a solar PV installation or a second heat source.

Built-In System Components

Comes with an integrated expansion vessel, circulation pump, safety valve, air vent and pressure gauge, reducing the number of separate parts an installer needs to source.

Modulating Output

Higher-output versions can be split into lower power stages via the control panel, allowing the same unit to be de-rated to suit the actual heat loss of the property once installed.

Hygienisation Cycle

Where the DHW package is fitted, a built-in hygienisation function heats the cylinder to 70°C to control Legionella risk, recommended every 2 to 3 weeks.

Anti-Stop Protection

An automatic Anti-Stop function runs the pump for one minute every 14 days when the boiler is switched off, preventing the pump rotor from seizing between heating seasons.

Technical Specification — Elterm Sergeant (AsBN), 4-14kW band

Model codes (4-14kW band)

123006 (6kW) · 123009 (9kW) · 123012 (12kW)

Power outputs

4kW single-phase entry · 6kW · 9kW · 12kW (higher outputs to 24kW also available on this platform)

Electrical supply

6kW & 9kW: 230V single-phase or 400V 3-phase · 12kW: 400V 3-phase

Automation

Basic LED control panel

Energy efficiency class

D (ErP scale spans A+++ to D)

Boiler efficiency

99.5%

Max CH operating temperature

70°C

Max DHW operating temperature

65°C (with DHW package fitted)

Connections

¾" external (CH flow/return)

Built-in equipment

Expansion vessel, circulation pump, safety valve, air vent, pressure gauge

Optional DHW package

Electrovalve, cylinder sensor, activation code — requires min. 12kW coil cylinder (not supplied)

System compatibility

Sealed or open-vented (air-vented) central heating systems

Standards compliance

LVD, RoHS, EMC, WEEE, ErP directives

Manufacturer guarantee

24 months from installation date, subject to registered commissioning and boiler protection kit fitment

Electrical Protection by Power Output

4kW (1-phase)

1 x 20A fuse, 3 x 4mm² cable

6kW (1-phase)

1 x 32A fuse, 3 x 4mm² cable

6kW (3-phase)

3 x 10A fuse, 5 x 2.5mm² cable

9kW (3-phase)

3 x 16A fuse, 5 x 2.5mm² cable

12kW (3-phase)

3 x 20A fuse, 5 x 4mm² cable

Model

Power

Supply

DHW Package

Sergeant 6kW

6kW

230V or 400V

Optional (code 100003)

Sergeant 9kW

9kW

230V or 400V

Optional (code 100003)

Sergeant 12kW

12kW

400V

Optional (code 100003)

What's the difference between this and the heat-only version?

This is the same Elterm Sergeant boiler platform. On its own it heats a wet central heating circuit only. Fitting the optional DHW package adds priority control of a separate hot water cylinder, turning it into a system boiler that covers both heating and hot water.

Do I need to buy a hot water cylinder separately?

Yes. The DHW package only supplies the electrovalve, cylinder sensor and activation code; it requires a separately purchased indirect cylinder with a coil rated at a minimum of 12kW to work correctly.

What electrical supply is needed for a 9kW or 12kW model?

The 6kW and 9kW versions can run on either a 230V single-phase or 400V 3-phase supply. The 12kW version requires a 400V 3-phase supply. A qualified electrician should confirm fuse rating and cable size against the protection table above.

Is this boiler suitable for a flat without gas?

Yes, this power band (4-14kW) is well suited to flats and smaller homes, where its compact wall-mounted design and lack of a flue make installation straightforward.

How often does the hot water need hygienising?

Where the DHW package is fitted, Elterm recommends running the hygienisation cycle every 2 to 3 weeks. This heats the DHW circuit to 70°C to help control the risk of Legionella bacteria in the stored water.

BTU Calculator

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Room Dimensions

Length (in m):

Width (in m):

Height (in m):

Room Type

Living Room

Bedroom

Kitchen

Bathroom

Conservatory

Hallway

Glazing Type

Single Glazed

Double Glazed

Triple Glazed

External Walls

0 Wall

1 Wall

2 Walls

3 Walls

4 Walls

Insulation Level

Poor

Average

Good (New Build)

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Required Heating

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Watts

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