Keston K80, K50, K60, K260, K340 Range Guide

Modular Wall
Mounted
Ultra-High
Efficiency Gas
Condensing
Boilers

for Low Cost
Commercial
and Industrial
Heating

● Small diameter plastic flue systems

can be extended up to 39 metres
vertically or horizontally

● Low cost plastic flue material saving

thousands of pounds on installation
costs

● Boilers from 38 kW to 100 kW output

● Modular systems available to match

any heating output

● Compact size and preassembled

design reduces space requirements
and installation time.

CONDENSING BOILERS

Keston BOILERS

The commercial range of Keston wall mounted gas condensing boilers covers outputs from 38 kW
(Keston 130) to 100 kW (Keston 340) with single boiler units. As with all Keston Boilers each has
an extremely high efficiency performance of 98% (GCV).

Despite their powerful outputs each unit is designed for wall mounting though floor standing
installations can be accommodated for the Keston 260 and Keston 340 using an optional floor
standing frame.

Keston Boilers offer complete and cost effective solutions to commercial and industrial heating and
in all installations can offer the highest quality systems. These are very often at much lower costs
than a single commercial boiler of equivalent output.

● Practically any heating output possible with modular system

● Wall mounted with optional floor standing frame

● Compact size from 889H x 500W x 327D

● Up to 99.1% efficient – can save 30% or more on fuel bills

● with virtually no NOx emissions (Class 5 rated)

● Flue system is small diameter plastic pipe with lengths up to

39m (Keston 260 and 340) - vertical or horizontal - can
save thousands of pounds in installation costs

● Purpose designed boiler plant rigs available for easy

installation and drastically reduced site time.

● Simple and quick to install and maintain - all access from

front and top.

● Completely room sealed, can site practically anywhere,

no need for expensive dedicated boiler room with
combustion air ventilation.

● Integral shunt pumps on Keston 260 and 340 models

● Perfect match for Keston Spa hot water storage system -

high efficiency commercial models up to 450 litre
storage.

● No complicated PCB's

● Exceptionally high quality stainless steel single pass heat

exchanger

● LPG options available for Keston 130 and Keston 170

● CE Marked, British Gas Approved and manufactured to

ISO 9001

Power POINTS

COMBUSTION EMISSIONS NOx PPM

The patented
micro-mesh burner
produces a low flame
temperature and super
low NOx combustion
at levels well below
any published
requirement.

120
110
100

90
80
70
60
50
40
30
20
10

CONVENTIONAL

SYSTEMS

PROPOSED

GERMAN

‘BLUE-ANGEL’

LIMIT

KESTON

2

Keston Commercial - Higher Output Keston 260 and Keston 340

Following the immediate success of the Keston 130 (38 kW) and the Keston 170 (50 kW) light
commercial models Keston Boilers launched two additional commercial condensing gas boilers to
further extend its range of ultra high efficiency boilers

The Keston 260 (76 kW output) and Keston 340 (100 kW output) are unique in concept and design
and each have an exceptionally high efficiency at 98% (GCV).

Despite their powerful output the boilers are designed to be wall mounted, though floor standing installations can be
accommodated using the optional floor standing frame.

The compact size means these boilers can be sited practically anywhere without the need for a dedicated boiler room.

Each model comprises two boiler modules with individual gas valve, fans, burners and heat exchanger assemblies. Each module
operates completely independently and is automatically sequenced to offer maximum load matching.

Firing sequence is regularly rotated automatically to even usage levels.

Unique FLUE SYSTEM

All Keston boilers have the advantage of a small diameter
plastic flue system and the commercial range is no
exception.

The 50 mm diameter plastic flue used on the Keston 130
and Keston 170 can be extended up to 29 metres away
from the unit. The 100 mm diameter plastic flue on the
Keston 260 and Keston 340 can be extended up to 39
metres. All boilers can accommodate vertical or horizontal
flue routes. The usage of low cost plastic pipe for the flue
can save thousands of pounds on installation costs when
compared to a conventional flue. In refurbishment projects
there is no need for expensive relining of the flue. This
system is also ideal for buildings with difficult flue options and
particularly listed buildings with various restrictions.

Added benefits of
the flue flexibility is
that the boiler can
be sited practically
anywhere in the
most convenient
position and the
flue can be
terminated in a
location where the
"plume" generated
with a condensing
boiler does not
cause a visual
nuisance.

Sheltered Housing Project:
3 Keston 170’s

How It Works

The Keston modules use
a high powered
combustion blower to
deliver a premix of gas
and air to a downward
firing burner in a high
efficiency single pass heat
exchanger. The heat exchanger is made from highly
corrosion resistant stainless steel formed into a tightly wound
coil. Hot combustion gases pass through the coil providing
heat to the water system.

Shunt pumps, integral to the appliance on the Keston 260
and Keston 340, will ensure each module receives the
correct water flow when firing.

The Keston boilers are of low mass and low water content
giving a rapid response when there is a call for heat.

The design of Keston boilers, with its single pass heat
exchanger, avoids the complications associated with other
condensing boilers and as a result does not require
complicated printed circuit boards. The unit is totally room
sealed and requires no ventilation for combustion air to the
room or compartment in which it is installed.

The Keston commercial boilers are exceptionally easy to install
and maintain and pipework header assemblies are available as
an option to assist speedy installation. They are completely
environmentally sound with negligible NOx emissions (Class 5
rated) and can save 30% on the heating bill.

Full Load Efficiency vs. Return Water Temperature

BOILER EFFICIENCIES IN %

WATER RETURNING TO BOILER °C

High efficiency condensing boilers produce more heat, using
the same amount of gas, than any other type of gas boiler.

20

30 40

50

60 70

100

95
90
85
80
75
70

CONDENSING

STAN

DARD

3