Elterm Ensign Electric Combi Boiler 9kW CH / 14kW DHW

Description

The Elterm Ensign (AsC) 9kW CH / 11-24kW DHW electric combi boiler combines a central heating body and an instantaneous hot water heater in a single wall-mounted housing. It delivers 9kW of central heating output alongside 11-24kW of instantaneous domestic hot water, with no external hot water cylinder required — making it a compact fit for flats and smaller properties without mains gas.

Manufactured by Elterm using Basic LED automation, the Ensign's two functions operate independently of one another: the central heating and hot water sides can run at the same time without one affecting the other's temperature control. The unit includes 4x PV-ready functionality for cooperation with a solar installation, and can be paired with any voltage-free (0V) wired or wireless room controller.

9kW

Central heating output

11-24kW

DHW instantaneous output

Class D

Energy efficiency (A+++ to D)

24 months

Manufacturer guarantee

70°C

Max CH operating temperature

4x

PV-ready features included

Installation, Electrical Safety & Warranty

Electrical and hydraulic assembly must be carried out by a qualified, legally authorised installer, with overcurrent and RCD protection sized correctly for the model. To keep the manufacturer's extended guarantee valid, a boiler protection kit (magnetic filter and water descaler) must be fitted and the heating system flushed, cleansed and inhibited to BS 7593 before commissioning.

Instantaneous Hot Water — Usage Notes

The DHW side heats water on demand rather than storing it, so it is best suited to one hot water outlet running at a time (or two taps together on the higher-output 11-24kW versions). A magnetic filter on the hot water side is strongly recommended to protect the instantaneous heater from limescale damage and blockage, particularly in hard water areas.

Two Systems, One Housing

A central heating boiler and an instantaneous DHW flow heater share one wall-mounted unit, cutting installation cost and freeing up space that a separate cylinder would otherwise use.

Independent Operation

The central heating and hot water functions operate independently of each other, so demand on one side does not interrupt performance on the other.

PV Ready Functionality

Includes 4x PV-ready features — an operation counter, adjustable maximum power lock, a voltage-free (0V) contact for external control, and a disconnectable contact for a second heat source — to help the boiler cooperate with solar generation.

Sealed or Open Vented

Can operate in both sealed and air-vented heating systems, giving flexibility when retrofitting into an existing wet central heating circuit.

Compact Wall-Mounted Design

No cylinder, no flue, and a single wall-mounted footprint make the Ensign well suited to flats and properties where space and installation access are limited.

GSM & Wi-Fi Control Options

Compatible with optional GSM and Wi-Fi controllers, plus radio control variants for room and weather-compensated operation, for remote monitoring and adjustment.

Technical Specification — Elterm Ensign (AsC) 9kW CH / 11-24kW DHW

Model code

135709 (11/13kW DHW) · 135809 (18/21/24kW DHW)

Central heating power

9kW / 400V

DHW instantaneous power

11-24kW (modulated)

Automation

Basic LED control panel

Energy efficiency class

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

Max CH operating temperature

70°C

Max DHW operating temperature

65°C

CH connections

¾" external

DHW connections

½" external

Central heating equipment included

4l expansion vessel, circulation pump, safety valve, air vent, electronic pressure gauge

DHW flow rate (Δt = 30°C)

5.7-6.9 l/min (11-13kW flow heater) or up to 12.2 l/min (18-24kW flow heater variants on this platform)

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; extended guarantee available subject to protection kit and BS 7593 flushing/inhibiting

Can the Ensign fill a bath without running out of hot water?

Yes. Because it heats water instantaneously rather than storing it in a cylinder, the DHW side does not run out the way a stored hot water system can — provided demand stays within the flow rate the unit is rated for.

Can the 9kW central heating side run at the same time as the hot water?

Yes. The central heating and DHW functions in the Ensign operate independently of one another, so hot water demand does not reduce central heating output, and vice versa.

Do I need a hot water cylinder with this boiler?

No. The Ensign's built-in instantaneous flow heater removes the need for a separate hot water storage cylinder, which is one of the main reasons it suits flats and space-constrained properties.

What protects the hot water side from limescale?

A magnetic filter fitted on the hot water inlet is strongly recommended to prevent limescale build-up and protect the instantaneous heater from damage or blockage, especially in hard water areas.

What electrical supply does this model need?

Confirm this against the rating plate and a qualified electrician's assessment: Elterm's manufacturer documentation shows the Ensign range built mainly for 400V 3-phase supply, though some versions and UK listings describe single-phase configurations. Never assume the supply type without checking the specific unit.

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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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