The EHC Comet 7/9/12/14.4kW System Electric Boiler (EHC.CS14.4KW) is the mid-power model in the Comet Standard System range, built on over 21 years of EHC electric heating expertise. It is designed for properties with a higher heat demand than the base model can cover, delivering central heating and domestic hot water via an S-Plan configuration from a single wall-mounted unit.
This model runs on a single-phase 240V supply with four selectable output settings — 7.2kW, 9.6kW, 12kW or 14.4kW — configured on-site to match the property’s heat loss and available electrical capacity. The pump, expansion vessel, automatic air vent, auto-bypass and high-current thermal cut-out are all factory-fitted inside the casing, removing the need for external plumbing or pipework.
7.2–14.4 kW
Selectable Output
240V 1N~
Single Phase Supply
5 Years
Manufacturer Warranty
Important Safety Information
This boiler must be installed by a qualified electrician in accordance with BS 7671 Wiring Regulations. A 30mA RCD, dedicated local isolation and an in-line magnetic filter are all mandatory — failure to fit a magnetic filter to this boiler will invalidate the manufacturer’s warranty.
Please Note
At this power range, MCB ratings run up to 63A and load current up to 60A at the top 14.4kW setting. A load check of the property’s incoming electrical supply is strongly recommended, and upgrading the main fuse is often required. Supply cable size must be calculated by a qualified electrician in line with BS 7671.
Key Features
Flexible Multi-Output Technology
Four selectable outputs (7.2, 9.6, 12 or 14.4kW) let installers range-rate the boiler on site to match the exact heat loss of larger properties.
Six-Stage Modulation
A stainless steel heat exchanger with six-stage heating modulates output in real time, reducing electricity consumption and running costs.
Virtually Silent Operation
Rated at just 41dB, the Comet Standard operates quietly enough for airing cupboards, kitchens and utility rooms.
Underfloor Heating Compatible
Adjustable flow temperature from 20–85°C makes it equally suited to underfloor heating and traditional radiator systems.
Compact Wall-Mounted Design
All core components — pump, expansion vessel, auto-air vent and auto-bypass — are built into a single 716 x 316 x 235mm casing for a one-person lift and install.
Trusted EHC Technology & Support
Backed by 21+ years of UK electric heating manufacture and a 5-year manufacturer’s warranty (registration required).
Specification
Performance
Rated Power Output
7.2 / 9.6 / 12.0 / 14.4 kW
Rated Voltage
240V 1N~ (single phase)
Outlet Flow Temperature Range
20–85°C
Maximum Temperature
100°C
Minimum System Flow Rate
4.5 l/min
Electrical Data
MCB Rating
40 / 50 / 63 / 63 A
Load Current
30.0 / 40.0 / 50.0 / 60.0 A
Minimum Supply Cable Cross-Section*
4 / 6 / 10 mm²
Maximum Supply Cable Cross-Section
16 mm²
Maximum Allowed Network Impedance
0.24 / 0.22 Ω
Hydraulics & Build
Boiler Connections
G 3/4" (internal thread)
Maximum System Pressure
0.3 MPa (3 bar)
Minimum System Pressure
0.05 MPa (0.5 bar)
Built-In Expansion Vessel
5 litres, 1.5 bar precharge
Safety Class (Ingress Protection)
IP 22
Heat Exchanger
Stainless steel
Dimensions & Warranty
Dimensions (H x W x D)
716 x 316 x 235 mm
Manufacturer Warranty
5 years (registration required, T&Cs apply)
Good to Know
*Minimum cable cross-sections are the manufacturer’s stated minimums only. The cable size for your installation must be calculated separately by a qualified electrician in accordance with BS 7671, accounting for cable type, routing and supply voltage deviation.
Frequently Asked Questions
Will my property’s electrics cope with the 14.4kW setting?
At 14.4kW this boiler draws up to 60A and requires a 63A MCB. A qualified electrician should carry out a full load check of the incoming supply before installation, as an upgrade to the property’s main fuse is often needed at this output.
Can this boiler provide hot water as well as heating?
Yes. The EHC.CS14.4KW can be installed for heating only, or for combined heating and domestic hot water when wired in an ‘S’ Plan configuration alongside a compatible hot water cylinder and twin-channel control.
Do I need to choose one fixed output, or can it be changed later?
The boiler ships with all four output settings available. The installer configures the required output (7.2, 9.6, 12 or 14.4kW) during commissioning via the DIP switches and control panel software — it is not locked to a single kW rating at the factory.
Is a magnetic filter really mandatory?
Yes. A magnetic filter must be fitted to the return of this boiler. This is a manufacturer warranty condition, not just best practice — installing without one will void the warranty regardless of any other fault.
Is this boiler suitable for underfloor heating?
Yes. The adjustable flow temperature range of 20–85°C covers both low-temperature underfloor systems and standard radiator circuits, and the boiler is compatible with wet underfloor heating installations.