Page 6 Introduction
1.1 HOW A CONDENSING BOILER
OPERATES
During the combustion process, hydrogen and oxygen combine
to produce heat and water vapour. The water vapour produced
is in the form of superheated steam in the heat exchanger. This
superheated steam contains sensible heat (available heat) and
latent heat (heat locked up in the flue gas). A conventional boiler
cannot recover any of the latent heat and this energy is lost to the
atmosphere through the flue.
The Grant Vortex condensing boiler contains an extra heat
exchanger which is designed to recover the latent heat normally
lost by a conventional boiler. It does this by cooling the flue gases
to below 90°C, thus extracting more sensible heat and some of the
latent heat. This is achieved by cooling the flue gases to their dew
point (approximately 55°C).
To ensure maximum efficiency, the boiler return temperature should
be 55°C or less, this will enable the latent heat to be condensed out
of the flue gases.
• The boiler will achieve net thermal efficiencies of 100%.
To achieve maximum performance from the Grant Vortex boiler,
it is recommended that the heating system is designed so that a
temperature differential of 20°C between the flow and return is
maintained.
The Grant Vortex boiler will however still operate at extremely high
efficiencies even when it is not in condensing mode and therefore
is suitable for fitting to an existing heating system without alteration
to the radiator sizes. The boiler is capable of a maximum flow
temperature of 75°C.
1.2 BOILER DESCRIPTION
The Grant Vortex range of automatic pressure jet oil boilers have
been designed for use with a fully pumped central heating system
with indirect domestic hot water cylinder.
They are not suitable for use with either a direct cylinder or a
‘primatic’ cylinder or gravity hot water.
The boilers are suitable for use on open vented or sealed central
heating systems. System models are supplied with the necessary
components factory fitted. Refer to Section 7.
All boilers are supplied with the control panel and burner factory
fitted.
All the models in the current Grant Vortex range of boilers are
designed to comply with the maximum NOx emissions* under the
Energy-related Products Directive (ErP).
* From the 26th September 2018, the maximum NOx emissions for
all new oil fired boilers (up to and including 400kW for both new
build and replacement boiler installations) is 120mg/kWh.
1.3 FLUE OPTIONS
The boilers can be connected to either a conventional flue system or
a balanced flue system, as required.
1.3.1 FOR CONVENTIONAL FLUE
APPLICATIONS
Where a chimney is to be lined - Grant recommends the use of the
Grant ‘Orange’ flue system, specifically designed for the Vortex
range of condensing boilers. Refer to Section 9.2 for further details.
Where a rigid conventional flue - either internal or external - is
required, Grant recommends the use of the Grant ‘Green’ and
‘Orange’ flue system components. As no flue adaptor is supplied
with the boiler it will be necessary to purchase the Grant CF
adaptor kit in order to correctly connect this system to the boiler.
Flue adaptor kit (Grant product code: CFA15/70) is used for all
models as they all use the 100 mm ‘Green’ and ‘Orange’ system
components to construct a flue of maximum vertical height 19
metres.
1.3.2 FOR BALANCED FLUE
APPLICATIONS
The following flue kits are available from Grant Ireland. Refer to
Section 9.4.
Yellow system
Standard low level concentric balanced flue - components
available:
• Extensions 225 mm, 450 mm and 675 mm
• 90° extension elbow
• 45° extension elbow
• 45° elbow
• Plume diverter kits
Green system
Standard external high level/vertical flue starter kit (room sealed) -
components available:
• External high level/vertical flue starter kit short (room sealed)
• Extensions 150 mm, 250 mm, 450 mm, 950 mm
• Adjustable extension 195 to 270 mm
• 45° elbow
• High level terminal
• Vertical terminal
White system
High level and vertical concentric balanced flue kit- components
available:
• Extensions 225 mm, 450 mm, 950 mm
• Adjustable 275 to 450 mm
• Vertical concentric balanced flue kit
• Extensions 225 mm, 450 mm, 950 mm
• Adjustable extension 275 to 450 mm
• 45° elbow
Plume Kit (15/26 models only)
A flexible vertical balanced flue system designed to be fitted inside
1 INTRODUCTION
The flue system materials and construction
MUST be suitable for use with oil-fired
condensing boilers. Failure to fit a suitable
conventional flue may invalidate the
guarantee on the boiler.
NOTE
