IT'S WHAT'S ON THE INSIDE THAT COUNTS
25kW condensing system boiler
Customer Benefits
- SEDBUK A Rate
- 5 Year Warranty*
- OpenTherm Compatible
- Compact Size – H-700mm, W-400mm, D-300mm
- Fully ErP compliant
- Backlit LCD
- Whisper Quiet in Operation
- Built in frost protection
- Integral colour coded valve kit eliminates unsightly valves below the boiler
- User friendly controls, simple and easy to use
- High density insulation
- Minimum low power of only 3.7kW further reduces energy cost


Installer Benefits
- Brass and Premium Branded Components for Lasting Quality
- Stainless Steel main heat exchanger
- Fully accessible from the front making service easier
- Side clearance of only 1mm required
- Easy release control panel allows easy access for servicing
- Built-in deep condensate trap designed to reduce external nuisance freezing in winter
- Multi fix wall hanging bracket available (optional)
- Flexible condensation pipe for multi positioning discharge drain
- Lightweight design to aid installation
- Removable side panels
- Built in automatic by-pass
- Low Nox class 6 – 36.06 mg/kWh
- Anti-locking pump feature
- Stand-off bracket available for piping down the back of the appliance (optional)
Simple yet innovative, the control display on the HE98S System slides up with ease to allow easy access when servicing.
Clear View Display Screen
The HE98S System combination boiler has a high resolution backlit LCD screen, featuring customer friendly buttons for optimum operation, making it easy to use in poor light conditions. This feature enables the user to easily set the heating temperature, and view the system pressure.

Single coil stainless steel heat exchanger

The stainless steel single coil heat exchanger will ensure constant water speeds over a long lifecycle, coupled with this being able to access the heat exchanger from the front facilitates ease of service through the lifecycle of the boiler. The coil itself is designed to have wide water ways which lessens the likelihood of debris build up in the heat exchanger, the absence of manifolds lengthens the life expectancy of the heat exchanger by reducing the number of weld points and the number of seals.

OpenTherm
(compatible room stat required)
OpenTherm boilers provide more precise control directly from the room thermostat to the boiler’s software which modulates the gas valve and central heating pump. This allows the precise gas input requirement to match the varying demand signal i.e. if the house needs to be one degree warmer the control tells the boiler it can start and run at a lower power. By reducing the flow temperature to a minimum of the heat required,the flow temperature is kept below the dew point (50°C),thus allowing the boiler to operate in condensing mode which is more efficient. Without OpenTherm even with the best controls the boiler will always run at full power consuming significantly more energy (both gas and electric) affecting the homeowner’s energy bill. Whereas with our HE98S System by just applying the necessary heat there is a significant saving available and all of this is done automatically by the boiler and its controls.

Demand heat by using a basic switch live into
the side of the PCB housing, or wire direct to
the main PCB with volt free or OpenTherm.
Dimensions & Clearances

Flue Options
The HE98S System can be fitted with either a 100mm standard (concentric), a 125mm flue duct or a twin (eccentric) flue duct, which can be installed either vertical or horizontal, depending on the customer’s requirement.
A one metre standard horizontal flue kit is supplied separately; this can extend to 8 metres if required, or 13 metres vertical (maximum without bends). The above flue arrangements should fit most requirements however, alternative systems (Twin or 125mm) are available.
See installation manual for all flue lengths and options.
Part | Description Flue 60/100 | Part No |
1 | 1 metre horizontal flue kit | TER160050 |
2 | Straight flue header/Sample Point | COL160050 |
3 | 1 metre high plume kit | TER110101 |
4 | 1 metre flue extension | PRFE |
5 | 45o in line flue bend | PR45FBI |
6 | 90o in line flue bend | PR90FBI |
7 | Flashing sleeve/plate | TEG060050 |
8 | 1 metre vertical terminal | TER110200 |
9 | 90o flue exhaust deflection bend | CUR110100 |
10 | 45o flue exhaust deflection bend | CUR110050 |


Quality
Built to exacting ISO 9001 standards using quality components, all our boilers carry the European CE mark. Each Ravenheat appliance undergoes rigorous testing and operating procedure before being carefully packed for maximum protection, ready to leave our factory.
Boiler Specification
HE98S SYSTEM | |
Central Heating Max/Min Output (Adjustable Modulation) | 3.7 - 26.4 kW |
Expansion Vessel | 8L |
Maximum Central Heating Temperature | 80oC |
Installation Clearance Side Top Below | 1 mm 125 mm 80 - 150 mm |
Connections: Gas Heating Flow And Return Condensate (push fit) | 15mm 22mm 3/4" |
Flue Connection | 100 mm |
Electrical Mains Supply | 230V 50HZ Fused 3amp |
Nat Gas AB and A 2005/2009 | 90.3 / 88.9% |
μs seasonal space heating energy efficiency | 92% |
NOx Class | 6 (36.06mg/kWh) |
OpenTherm Compatible | Yes |
Noise level | 52 dB |
Auxiliary Electricity Consumption elmax at full load elmin at part load PSB in standby mode | 0.045 kW 0.017 kW 0.005 kW |

CONDITIONS OF 5 YEAR WARRANTY
Boiler must be correctly installed. Boiler must be commissioned by a Gas Safe registered engineer. Boiler must be registered with Ravenheat upon purchase (so 5 year warranty can be activated). Boiler must be correctly maintained and serviced by a qualified, competent person. For any other information please refer to the user guide and installation instructions.
Technical After-Sales Service
Ravenheat have a technical helpline at its central headquarters in Leeds. Service engineers or their customers have the satisfaction of knowing they will receive advice, and the knowledge that one of Ravenheat’s own technicians is on hand should an on-site visit be required. Ravenheat only use their own highly qualified technicians thereby ensuring the highest quality and most reliable customer care.
Ravenheat run their own unique comprehensive installer training programme working alongside the regulative bodies and trade associations. The training programme is open to any Gas Safe Registered installer. For further information visit our training days page or emailing us at [email protected].
