keston qSpa 120 User guide

qSpa & qSpa Solar

Installation and Servicing Instructions

When replacing any part on this appliance, use only spare parts that you can be

assured conform to the safety and performance specification that we require.

Do not use reconditioned or copy parts that have not been clearly authorised by Keston.

For the very latest copy of literature for specification and maintenance practices visit our website

www.keston.co.uk where you can download the relevant information in PDF format.

ISSUE 06: MAY 2017

These instructions should be read in conjunction with the installation/servicing
instructions issued by the manufacturer of the heat source being used.

Any installation must be in accordance with the relevant requirements of the Gas
Safety Regulations, Building Regulations, I.E.E. Wiring Regulations and the Water Fitting
Regulations (England and Wales) or Water Byelaws (Scotland). It should be read in
accordance with the relevant recommendations of the following:
BS 6798; BS EN 12828, BS EN 12831, BS EN 14336; BS 5546;
BS 5440:1; BS 5440:2; CP 331:3
BS EN 806-1 to 5, BS EN 8558:2011: BS EN 1458-1:2011 and BS 7593:2006

qSpa is covered by Section G3 of the Building Regulations (England and Wales)
Technical Standard P3 (Scotland) and Building Regulation P5 (Northern Ireland).
Compliance can be achieved via a Competent Person Self Certication Scheme or
noticaton of installation to the Local Authority Building Control Department.

It must be installed by a competent person as dened by the relevant regulations.
Manufacturers notes must NOT be taken as over-riding statutory obligations.

This appliance is not intended for use by persons (including children) with reduced
physical, sensory or mental capabilities, or lack of experience and knowledge unless
they have been given supervision or instruction concerning use of the appliance by
a person responsible for their safety. Children should be supervised at all times to
ensure they do not play with the appliance.

This information is provided to assist generally in the selection of equipment.
Responsibility for selection and specication of our equipment must however remain
that of our customer and any experts or consultants concerned with the installation(s).

ISSUE 06: MAY 2017

Section Page

DESIGN

Description 3

Technical Information 6

System Design 8

INSTALLATION

Installation 10

Commissioning 20

SERVICING AND MAINTENANCE

Servicing and Maintenance 21

Fault Finding 22

Short Parts List 25

APPENDIX

Appendix 26

Terms & Conditions 27

Notes 28

Please note: that we do not therefore accept any responsibility for matters of
design selection or specication, for the eectiveness of an installation or system
containing one of our products unless specically requested to do so in writing.

All goods are sold subject to our Conditions of Sale which are set out at the rear of this
specication. In the interest of continuously improving the qSpa range, Keston Heating
reserve the right to modify the product without notice, and in these circumstances
this booklet, which is accurate at the time of printing, should be disregarded. An
updated set of Instructions will be produced and supplied with new appliances and
will be made available for other appliances on request.

qSpa is produced under an ISO 9001:2008 Quality Management System approved
by BSI.

Benchmark places responsibilities on both manufacturers and installers. The purpose is to
ensure that customers are provided with the correct equipment for their needs, that it is
installed, commissioned and serviced in accordance with the manufacturers instructions
by competent persons and that it meets the requirements of the appropriate Building
Regulations. The Benchmark Checklist can be used to demonstrate compliance with
Building Regulations and should be provided to the customer for future reference.

Benchmark Checklist 30

Benchmark Service Record 31

Page 2

DESIGN

Manufacturer: Keston Heating

Maximum inlet pressure to
Pressure reducing valve 12 bar
Operating pressure (PRV setting) 3 bar
Expansion vessel charge pressure 3 bar
Expansion relief valve setting 4.5 bar
Opening pressure of P & T Relief Valve 6 bar
Opening temperature of P & T Relief Valve 89-96°C
Energy cut-out thermostat setting 85°C
Max. working pressure - Primary heat exchanger (Indirect models) 6 bar
Max. working pressure - Solar heat exchanger (Solar models) 10 bar
Immersion heater rating 3kW, 240V AC

All cylinders are manufactured in accordance with the requirements of BS EN 12897
The tundish must be positioned so that it is visible to the occupant and is away from
electrical devices.

Components supplied with qSpa:

• Cold water inlet PRV combination valve/expansion relief

• Pressure and temperature relief valve

• Control thermostat

• Energy cut-out thermostat

• Energy cut-out motorised valve (indirects only)

• Tundish

• 3kW Immersion heater including control and cut out thermostats

• Expansion vessel/mounting bracket/exible hose

• Technical/user product literature

(Note: Please refer to table on pages 6-7 to conrm the quantity of immersion heaters
supplied with the unit)

In any situation where the volume of heated pipework (eg. secondary circulation
pipes or manifold pipework for multiple units) exceeds 10 litres, then an
additional expansion vessel must be tted to accommodate the extra expansion
volume.

Handling Before Installation

qSpa must be handled with care and stored the correct way up in a dry place. Any
manual handling/lifting operations will need to comply with the requirements of
the Manual Handling Operations Regulations issued by the H.S.E. The appliance can
be moved using a sack truck on the rear face although care should be taken and the
route should be even. In apartment buildings containing a number of storeys we would
recommend that the appliances are moved vertically in a mechanical lift. If it is proposed
to use a crane, expert advice should be obtained regarding the need for slings, lifting
beams etc.

A specic manual handling assessment is shown in Appendix at the rear of this manual.

Maintenance

Modifications should not be made to this
product. Replacement parts, including
immersion heaters, should be purchased from
Keston Heating, or agents approved by them.
Unvented hot water storage vessels need
regular routine checks, and these are detailed
below. It is for this reason that this manual must
always be left with the qSpa.

It is essential that these checks be carried out
at the time of boiler maintenance by a qualied
installer:

1. Manually open the relief valves in turn, and
check that water is discharged from the
valves and runs freely through the tundish
and out at the discharge point. Ensure that
the valves re-seat satisfactorily. (Note - the
water may be very hot).

2. It is important to check that the discharge
pipework is carrying the water away
adequately. Check for blockages etc. if it is
not.

3. Turn the mains water o and remove and
clean the strainer element in the Pressure
Reducing Valve.

4. Check the charge pressure in the expansion
vessel and repressurise if required

5. Re-ll the system and ensure that all relief
valves have re-seated.

6. The Benchmark Service Record should be
updated at each service.

7. Check the water pressure downstream of the
combination valve is 3 bar in static condition.

8. Check and if necessary, descale the heat
exchanger in hard water areas ie. above
200ppm (mg/l).

Note:

The cylinder is factory tted with a temperature
& pressure relief valve that must not be used for
any other purpose or removed.

The cylinder is factory tted with immersion
heaters with thermal cut outs. Immersions
without thermal cut outs must not be tted.

The Environment

This product has been manufactured using many recyclable materials, including the
approved HCFC/CFC free polyurethane foam insulation. At the end of its useful life, it
should be disposed of at a Local Authority Recycling Centre, to maximise the products
full environmental benets.

Page 3

DESCRIPTION

DESIGN

Figure 1

qSpa is a range of indirect unvented hot water
storage cylinders, manufactured in the latest
high quality duplex stainless steel. They are
designed to provide mains pressure hot water
and are supplied as a package which complies
with Section G3 of the Building Regulations.
The appliance is extremely well insulated using
high density HCFC free foam insulation with an
ozone depleting potential (ODP) of zero and a
global warming potential (GWP) of 2. It is tted
with all necessary safety devices and supplied
with all the necessary control devices to make
installation on site as easy as possible.

qSpa is available in two basic variants:

1. qSpa Indirect - For use with gas or oil boilers
(Figure 1). Unvented cylinders must not be
used with solid fuel boilers or steam as the
energy source.

2. qSpa Indirect Solar - For providing hot
water by solar gains and gas or oil boilers
(Figure 2). Unvented cylinders must not be
used with solid fuel boilers or steam as the
energy source.

qSpa Indirect

qSpa

INDIRECT

qSpa Indirect is an unvented hot water storage
cylinder and is provided with a high eciency
internal primary coil which is designed for use
with a gas or oil boiler and is suitable for both
open vented and sealed pumped primary
systems.

When used with a sealed heating system the
boiler must incorporate its own energy cut-out
overheat thermostat.

qSpa Indirect models are listed in table on

Page 6 & 7.

DESCRIPTION

Page 4

DESIGN

Figure 2

qSpa Indirect Solar

qSpa Indirect Solar is an unvented hot water
storage cylinder and is provided with a
high eciency internal primary coil which is
designed for use with a gas or oil boiler and
is suitable for both open vented and sealed
pumped primary systems.

When used with a sealed heating system the
boiler must incorporate its own energy cut-out
overheat thermostat.

A high eciency solar coil is positioned below
the primary coil to ensure maximum benet of
solar gain energy.

qSpa Indirect Solar models are listed in table

on Page 6 & 7.

Note:
The cold supply elbow c/w drain tapping
must be tted as shown in gs 1 and 2. A
exible hose can then be connected to the
drain tapping and, providing the hose runs
below the lowest level of the cylinder, then
all the water contents can be drained out
by syphonic action. (The cold feed pipe dips
internally to the base of the cylinder.)

qSpa

INDIRECT SOLAR

Page 5

DESCRIPTION

DESIGN

Table 1

L

P

Solar Indirect

A

B

I

D

E

K

Indirect

A

C

D

F

J

B

G

E

I

C

N

J

G

M

Model

qSpa

90

120

150

180

210

250

300

400

Solar qSpa

180

210

Stock Code

KESPLUIN090 A 32 91 20 111 3 12 764 550 522 n/a 382 345 n/a 45.1 272 235 325 n/a n/a n/a n/a n/a n/a 16.5 0.59 0.165 n/a n/a 17 n/a

KESPLUIN120 B 39 119 23 142 3 12 931 550 689 n/a 437 345 n/a 63.1 327 235 325 n/a n/a n/a n/a n/a n/a 18 0.59 0.165 n/a n/a 21 n/a

KESPLUIN150 B 47 148 26 174 3 18 1118 550 876 n/a 499 385 n/a 83.2 389 235 365 n/a n/a n/a n/a n/a n/a 18.5 0.68 0.191 n/a n/a 25 n/a

KESPLUIN180 B 55 178 30 208 3 18 1306 550 1064 n/a 561 425 n/a 103.4 451 235 405 n/a n/a n/a n/a n/a n/a 19 0.78 0.216 n/a n/a 30 n/a

KESPLUIN210 B 62 208 33 241 3 24 1494 550 1252 1141 632 425 n/a 123.7 513 235 405 n/a n/a n/a n/a n/a n/a 20.5 0.78 0.216 n/a n/a 32 n/a

KESPLUIN250 C 74 248 38 286 3 24 1744 550 1502 1353 955 505 705 110.5 595 235 485 n/a n/a n/a n/a n/a n/a 21.5 0.97 0.241 n/a n/a 36 n/a

KESPLUIN300 C 86 287 43 330 3 35 1990 550 1748 1562 1092 505 786 128.5 676 235 485 n/a n/a n/a n/a n/a n/a 25 0.97 0.241 n/a n/a 38 n/a

KESPLUIN400 D 118 400 55 455 3 2 x 24 2030 630 1787 1595 1117 566 799 180 669 235 546 n/a n/a n/a n/a n/a n/a 30.5 1.27 0.31 n/a n/a 41 n/a

KESPLUIN180S B 55 178 31 209 3 18 1306 550 1064 n/a 693 385 n/a 82.2 859 879 969 235 365 451 941 220 n/a 18 0.59 0.165 0.68 0.191 28 96

KESPLUIN210S B 62 208 35 243 3 24 1494 550 1252 1141 736 385 n/a 105.5 922 922 1052 235 365 513 1064 243 n/a 18.5 0.68 0.191 0.68 0.191 35 101

Heat Loss

Energy Eciency Class

Watts Litres kg kg bar Litres A=mm mm B=mm C=mm D=mm E=mm F=mm Litres G=mm I=mm J=mm K=mm L=mm M=mm N=mm P=mm R=mm kW m

Capacity (Total Volume)

Weight - Full

Weight - Empty

Expansion Vessel size.

expansion valve set at 4.5 bar

cold supply, expansion vessel connection and

Pressure Regulator 3 bar inlet group c/w balance

Pre-charged to 3 bar

Overall Height

Overall Diameter

Pressure & Temperature

Return Tapping

22mm Secondary

Relief Valve 6bar 90°C

250

300

400

KESPLUIN250S C 74 248 40 288 3 24 1744 550 1502 1353 796 505 n/a 136 1002 982 1152 235 485 595 1252 275 n/a 19 0.78 0.216 0.97 0.241 38 107

KESPLUIN300S C 86 287 44 331 3 35 1990 550 1748 1562 922 505 n/a 155.3 1128 1108 1278 235 485 676 1128 305 n/a 20.5 0.78 0.216 0.97 0.241 41 125

KESPLUIN400S D 118 400 59 459 3 2 x 24 2030 630 1784 1592 872 557 n/a 190 1060 930 1190 238 548 651 1383 357 n/a 22 0.97 0.241 1.27 0.31 45 165

TECHNICAL INFORMATION

Page 6

DESIGN

NOTES

1. Not all models - see table 2.

2. Recovery times based on Primary
Coil/I.H. duty (ie. assumes the boiler
output is adequate).

3. All connections are supplied with
compression fittings for direct
connection to copper pipework.

4. The diagrams shown are generic.
For exact product specification
refer to the table eg. the number

5

3

°

°

5

1

5

°

1

1

°

5

°

5

,

7

of immersion heaters varies
depending on model.

5. Heat up and recovery times based
on 0.25 l/s primary ow rate and at
82°C ow temperature.

Cold Feed 22mm

Heater - High Level

On Peak Immersion

Compression Connection

Heater - Low Level

O Peak Immersion

Volume of On Peak Water

Heated

Coil

Connection

Connection

22mm Solar Flow

22mm Solar Return

Compression Connection

Dual Control & Overheat Stat

22mm Primary Return Compression

(28mm tails for 400 litre model)

22mm Primary Flow Compression

(28mm tails for 400 litre model)

Compression Connection

Solar Pocket

Solar Pocket

Heater - Low Level

Dual Control & Overheat Stat

Second O Peak Immersion

kW Rating of Primary Coil

Surface Area of

Primary Heater Coil

2

bar m2bar min Litres

Pressure Loss Across

Primary Heater Coil

Surface Area of

Solar Heater Coil

Pressure Loss Across Solar Heater

Heat Up Time from 15°C to 60°C

(applies to Primary Heat Source only)

Dedicated Solar Volume

Page 7

TECHNICAL INFORMATION

DESIGN

1

2

3

4

6

7

9

5

8

qSpa Indirect

Basic Appliance

1. Hot water draw o (22mm) compression

2. Temperature & pressure relief valve 89-96°/6
bar

3. Hot water secondary return 22mm

(not tted to smaller sizes, see table 1)

4. Immersion heater 1¾” BSP 3kW

5. 22mm cold supply compression

6. Immersion heater 1¾” BSP 3kW

7. Dual control/overheat stat pocket (22mm)

8. Primary return (22mm)

- (28mm tails for 400 litre models)

9. Primary ow (22mm)

- (28mm tails for 400 litre models)

Part G3 loose components supplied in a
separate box

A. Combination inlet group incorporating

pressure reducing valve, strainer, check
valve, balance cold take o point, expansion
relief valve and expansion vessel connection
points.

B. Potable expansion vessels c/w exible hose

and integral wall bracket

C. Tundish
D. Dual control thermostat and combined

overheat thermostat

E. Two port (22mm) zone valve for
primary circuit
F. Wiring junction box for primary system

SYSTEM DESIGN

Page 8

DESIGN

11

10

1

2

3

12

8

7

4

9

6

5

12

qSpa Indirect Solar

Basic Appliance

1. Hot water draw o (22mm) compression

2. Temperature & pressure relief valve 89-96°/6

bar

3. Hot water secondary return 22mm
(not tted to smaller sizes, see table 2)

4. Immersion heater 1¾” BSP 3kW

5. 22mm cold supply

6. Dual control/Overheat stat pocket (solar)

7. Primary return (22mm)

- (28mm tails for 400 litre models)

8. Primary ow (22mm)

- (28mm tails for 400 litre models)

9. Dual control/Overheat stat pocket (boiler)

10. Solar coil return to panel collector (22mm)

compression

11.

Solar coil ow from panel (22mm) compression

12. Solar thermostat pocket

Part G3 loose components supplied in a
separate box

A.

Combination inlet group incorporating
pressure reducing valve, strainer, check valve,
balance cold take o point, expansion relief
valve and expansion vessel connection points.

B. Potable expansion vessels c/w exible hose

and integral wall bracket
C. Tundish
D. Dual control thermostat and combined

overheat thermostat (x2)
E. Two port (22mm) zone valve for
primary circuit
F. Wiring junction box for primary system

Page 9

SYSTEM DESIGN

INSTALLATION

General Design Considerations

The cupboard footprint needs to be at least 650mm square for standard units up to
300 litres, 730mm for 400 litre and 575mm for slimline units. The base chosen for the
cylinder should be level and capable of supporting the weight of the unit when full of
water as shown in General Data. The discharge pipework for the safety valves must have
a minimum fall of 1 : 200 from the unit to a safe discharge point. All exposed pipework
and ttings on the cylinder should be insulated, and the unit should NOT be xed in a
location where the contents could freeze.

In new systems, pipes should be insulated to comply with building regs, the maximum
permissible heat loss is indicated in the table opposite, and labelled accordingly as follows:
i. Primary circulation pipes for domestic hot water circuits should be insulated

through their length, subject only to practical constraints imposed by the need
to penetrate joists and other structural elements.

ii. All pipes connected to hot water storage vessels, including the vent pipe, should

be insulated for at least 1 metre from their points of connection to the cylinder (or
they should be insulated up to the point where they become concealed).

In replacement systems, whenever a boiler or hot water storage vessel is replaced in
an existing system, any pipes that are exposed as part of the work or are otherwise
accessible should be insulated as recommended for new systems, or to some lesser
standard where practical constraints dictate.

The pipe connecting the boiler ow to the appliance must not be less than 22mm
copper or equivalent.

Standard and Slimline Model Selection Guide

Max number

Max hot water demand

1 shower room Bedsit (0) 90

1 bathroom 2 (2) 120

1 bathroom 4 (3) 120

1 bathroom + separate shower room 6 (4) 150

1 bathroom + 2 separate shower rooms or 2

bathrooms

2 bathrooms + separate shower room 7 (5) 210

2 bathrooms + 2 separate shower rooms 7 (5) 250

3 bathrooms + 2 separate showers rooms 9 (6) 300

3 bathrooms + 3 separate showers rooms 9 (6) 400

Solar Model Selection Guide

Max hot water demand Bedrooms

1 shower room Bedsit 180

1 bathroom 1-3 180

1 bathroom + 1 shower room 1-3 210

1 bathroom + 2 shower rooms 2-4 250

2 bathrooms + 1 shower room 3-4 300

2 bathrooms + 2 shower rooms 4-5 400

of bed spaces

(Bedrooms)

7 (5) 180

Indirect

litres

Indirect

litres

Insulation of pipework

Pipe outside

diameter

15mm 7.89W/m

22mm 9.12W/m

28mm 10.07W/m

35mm 11.08W/m

Further guidance on converting heat loss limits
to insulation thickness for specific thermal
conductivities is available in TIMSA “HVAC
guidance for achieving compliance with Part L
of the Building Regulations”.

Mains Water Supply

Existing properties with a 15mm supply will be
satisfactory provided the local mains pressure is
good, but should be conned to single bathroom
properties. For new properties where simultaneous
demand is required to more than one bathroom
or a bathroom and one or more en-suites, the
communication and service pipe into the dwelling
should be a minimum of 22mm (usually in the
form of a 25mm MDPE supply). The optimum
performance is achieved if the inlet pressure is
3 bar dynamic. However, the qSpa will function
with lower inlet pressures, but this will reduce the
performance. For optimum performance, 30L per
minute incoming mains ow should be present,
however the qSpa will work at lower ow rates,
although performance will be aected. Normally
qSpa provides well in excess of 40 litres/min in
most conditions. Flow rates for ALL mains pressure
systems are subject to district pressures and system
dynamic loss. Particularly on larger properties with
more than one bathroom, the pipe sizes should be
calculated in accordance with BS EN 806-3:2006
and BS 8558:2011.

Model Selection

The suggested model sizes are based on
typical hot water usage. For high specication
dwellings an increase of one model size should
be considered.

Maximum

heat loss

INSTALLATION

Page 10

INSTALLATION

General Restrictions

a. The highest hot or cold water draw o point should not exceed 10 metres above

the Pressure Reducing Valve.

b. An ascending spray type bidet or any other appliance with a Class 1 back-syphonage

risk requiring a type A air gap should not be used.

c. qSpa should not be used where steam is the primary heating medium, or in a

situation where maintenance is likely to be neglected.
d. Unvented cylinders are not suitable for use with solid fuel boilers.
e. If the supply to the mixer ttings (other than a dual outlet type) is not taken from

the balanced supply the system will become over pressurized and cause the

pressure relief valve to discharge. Over time this could also cause the premature

failure of the appliance itself which will not be covered by the warranty.

f. In larger properties with a number of bathrooms/en-suites and long pipe runs

we would recommend that the balance cold supply is provided with its own

pressure reducing valve and is not taken from the balanced cold connection on

the combination valve. In this case it will also be necessary to t a small expansion

vessel on the balanced cold water system to accommodate the pressure rise caused

by the increase in temperature of the balanced cold water.
g. Check the performance requirements of the terminal ttings with regard to ow/

pressure are suitable.
h. I n relation to potable water systems, expansion vessels shall be installed in a vertical

orientation and located so that the length of the connecting pipe work is kept to

a minimum.

Shower Fittings

Aerated taps are recommended to prevent splashing. Any type of shower mixing valve
can be used as long as both the hot and cold supplies are mains fed. However, all mains
pressure systems are subject to dynamic changes particularly when other hot and cold
taps/showers are opened and closed, which will cause changes in the water temperature
at mixed water outlets such as showers. For this reason and because these are now no
more expensive than a manual shower we strongly recommend the use of thermostatic
showers with this appliance. These must be used in 3 storey properties where the
impact on pressure/temperature of opening another tap in the system is greater than
normal. The shower head provided must also be suitable for mains pressure supplies.

Pipe Layout

In all mains pressure installations it is important
to remember that the incoming cold supply
must be shared between all terminal ttings. It
is important that a 22mm supply is brought to
the appliance and a 22mm take-o is continued
at least to the bath. If there are two baths, 28mm
pipework should be considered. One metre of
smaller diameter pipework, or ow restrictors,
should be provided on the nal connection to
all outlets so as to balance the water available.
In any event the distribution pipework should
generally be in accordance with BS EN806-1 to 5.

Plastic Pipework

This appliance is suitable for use with plastic
pipework as long as the material is recommended
for the purpose by the manufacturer and is installed
fully in accordance with their recommendations.

Secondary Hot Water Circulation

All models 210 litres and above are tted with
a secondary return tapping as standard (see
table on page 6 & 7 for details). If tted, an extra
expansion vessel may be necessary. A non­return valve MUST be FITTED near the return
connection. No valve or terminal tting should
be installed between the non return valve and
the cylinder. (See schematic arrangement on
page 13.) All pipes kept hot by the secondary
circulation should be insulated.

DHW

P&T

ERV/NRV

TO
EXTERNAL
TAP

DC

DC

M

DC

INCOMING COLD SUPPLY

PRV

SINK

SH

SCV

WM or DWM

WATER SOFTENER (IF NECESSARY )

WHB

SCV

DCV

Page 11

WC BATH

Note:
Cold supplies to single taps must be

taken from the mains cold water
system.

Cold supplies to mixer taps must be
taken from the balanced cold water
connection on the combination
valve.

WHB

W.C.

DC

DC

INSTALLATION

INSTALLATION

Typical Discharge Pipe Arrangement

15 mm
discharge
pipe

600 mm max.

P & T
Relief
Valve

300 mm

min.

22 mm metal pipe with continuous
fall up to 9m equivalent length (D2).

NOTES:

The discharge will consist of scalding
waterand steam. Asphalt, roong felt
and non-metallic rainwater goods may
be damaged by such discharges.

It is not acceptable to discharge straight
into a soil pipe.

Expansion
relief valve

Dotted line showing
alternative route with
single tundish being used

Discharge below
xed grating

Fixed Grating

Trapped gully

Pressure & Temperature/expansion Relief
Valve Pipework

The relief valve should be installed to discharge
in accordance with G3 of the Approved
Document of the Building Regulations and
should be piped to where it is visible, but will
not cause danger to persons or damage to
materials.

The following information is taken from
Approved Document G3 of the Building
Regulations and is provided to assist with
the design and installation of the discharge
pipework. However, the information is not
exhaustive and reference should always be
made to Approved Document G3 of the Building
Regulations. The nal decision regarding any
arrangements rests with Building Control and
it is recommended that their advice is sought
if you have any concerns regarding this aspect
of the installation.

The two safety valves will only discharge
water under fault conditions. When operating
normally water will not be discharged.

Worked Example

The example below is for G1/2 temperature relief valve with a discharge pipe (D2)
having 4 elbows and length of 7m from the tundish to the point of discharge.

From the table below:

Maximum resistance allowed for a straight length of 22mm copper discharge
pipe (D2) from a G1/2 temperature relief valve is: 9m subtract the resistance for
4 x 22mm elbows at 0.8m each = 3.2m.

Therefore the maximum permitted length equates to: 5.8m.

5.8m is less than the actual length of 7m therefore calculate the next largest size.

Maximum resistance allowed for a straight length of 28mm pipe (D2) from a G1/2
temperature relief valve equates to: 14m.

As the actual length is 7m, a 28mm (D2) copper pipe will be satisfactory.

Sizing of copper discharge pipe ‘D2’ for a temperature relief valve

with a G1/2 outlet size (as supplied)

Deduct the gure

Size of discharge

pipework

Maximum length of

straight pipe

(no bends or elbows)

below from the

maximum length for

each bend or elbow in

the discharge pipe

22mm Up to 9m 0.8m

28mm Up to 18m 1m

35mm Up to 27m 1.4m

The tundish should be vertical, located in the
same space as the unvented hot water storage
system and be tted as close as possible and
within 600mm of the safety device e.g. the
temperature relief valve.

The discharge pipe (D2) from the tundish should
terminate in a safe place where there is no risk
to persons in the vicinity of the discharge, be
of metal and:

a) Be at least one pipe size larger than the

nominal outlet size of the safety device unless
its total equivalent hydraulic resistance
exceeds that of a straight pipe 9m long
i.e. discharge pipes between 9m and 18m
equivalent resistance length should be at
least two sizes larger than the nominal outlet
size of the safety device, between 18 and
27m at least 3 sizes larger, and so on. Bends
must be taken into account in calculating
the ow resistance. Refer to the table and
the worked example.

An alternative approach for sizing discharge

pipes would be to follow BS EN 806-2:2005
Specication for design installation, testing
and maintenance of services supplying water
for domestic use within buildings and their
curtilages.

b) Have a vertical section of pipe at least

300mm long, below the tundish before any
elbows or bends in the pipe work.

c) Be installed with a continuous fall.

INSTALLATION

Page 12

INSTALLATION

d) It is preferable for the discharge to be visible at both the tundish and the nal point

of discharge but where this is not possible or practically dicult there should be

clear visibility at one or other of these locations. Examples of acceptable discharge

arrangements are:

1. Ideally below the xed grating and above the water seal in a trapped gulley.

2. Downward discharges at a low level; i.e. up to 100mm above external surfaces
such as car parks, hard standings, grassed areas etc are acceptable providing that
where children play or otherwise come into contact with discharges, a wire cage
or similar guard is positioned to prevent contact whilst maintaining visibility.

3. Discharges at a high level; e.g. into metal hopper and metal down pipe with the
end of the discharge pipe clearly visible (tundish visible or not) or onto a roof
capable of withstanding high temperature discharges of water and 3m from
any plastic guttering systems that would collect such discharges.

This is integral within the combination inlet
group to reduce the likelihood of contaminants
fouling the valve seat. Following installation this
line strainer must be cleaned and replaced. This
needs to be carried out on a regular basis. as part
of the annual maintenance/service check.

Tundish

This is to allow the discharge from any Relief
Valve to be seen. It must be tted away from
any electrical devices. See page 12 for discharge
pipework details.

Expansion Vessels Installation

4. Where a single common discharge pipe serves more than one system, it should
be at least one pipe size larger than the largest individual discharge pipe (D2)
to be connected.

5. If unvented hot water storage systems are installed where discharges form
safety devices may not be apparent i.e. in dwellings occupied by blind, inrm
or disabled people, consideration should be given to the installation of an
electronically operated device to warn when discharge takes place.

Safety

The safety devices supplied or tted on an qSpa are selected for their suitability for the
temperatures and pressures involved. They must not be changed, removed or by-passed
and it is essential that only genuine replacement parts supplied or approved by Keston
Heating are used. All parts are available to approved installers from Keston Heating.

Line Strainer

Schematic Diagram

Secondary

Return Circuit

Hot Outlet

To prevent water stagnation and particulate
accumulation affecting water quality, it is
recommended that the expansion vessel be
installed in the vertical orientation so that the
tting accommodating thermal expansion or a
pressure surge is:-

1. bottom fed and upright; and

2. that the connecting pipework to the tting:-

- rises continuously; and

- is kept to a minimum;

2 expansion vessels on 400 litre Models

All 400 litre models are supplied with two 24 litre
expansion vessels. These can be coupled together
and tted to the expansion cylinder tapping on
the combination inlet valve, or by some other
means on the cold/hot water inlet pipework.
There must be no valve on the pipe work between
the expansion cylinders and the unvented
cylinder which could prevent the expansion of
the water contained in the unvented cylinder
reaching the expansion cylinders.

Combination Inlet Group

Combines elements 1, 2 and 3 below.

Stop
Tap

Kitchen

Cold

Tap

Pump

Boiler

Flow

Boiler

Return

Non Return

Valve

To Drain

Immersion Heater

2 Port Valve

P&T
Relief Valve

Tundish

Expansion Vessel(s)

ERV

NRV

Combination

Page 13

PRV

Valve

Balanced

Cold

Outlets

1. Pressure Reducing Valve - The cold water
supply to any mixer taps/showers must
be taken from the cold water tapping of
this valve to ensure balanced hot and cold
pressures. This valve is factory set to ensure
the correct operating pressure for the qSpa.

2. Non Return Valve - This is integral with the
pressure reducing valve to prevent backow of
hot water towards cold water draw o points.

3. Cold Water Expansion Relief Valve - This safety
device is preset at the factory and will relieve
excess cold water pressure resulting from a
fault condition.

INSTALLATION

INSTALLATION

Combination Valve

I.V.

I.V.

If two qSpa cylinders are coupled together the secondary inlet and outlet pipes must
be balanced. The units must be tted on the same level.

Note: No valves must be tted between the expansion vessel and the storage cylinder(s).

Pressure & Temperature Relief Valve

This safety device is also pre-set at the factory and relieves before the temperature
reaches 100°C. It is also a Pressure Relief Valve, and is pre-set to 6 bar.

The immersion thermostat has two terminals
A and B. The Live (brown) wire should be
connected to terminal A and the Neutral (blue)
wire should be connected to terminal B. It has
been our experience that Crimp terminals make
better connections. The immersion heater must
be fully earthed (earth post) and connected via
a double pole isolator switch having a contact
separation at least 3mm, see diagram opposite.

Danger of electrocution: before making any
adjustments to the thermostat isolate the
immersion heater from the mains electricity
supply at the fuse spur unit.

The immersion heater thermostats incorporate
a manual reset safety/overheat cut out
thermostat. Should this operate, investigate
the cause before pressing the red reset button
labelled safety. If there is no apparent fault
adjust the control setting down slightly to
prevent nuisance tripping.

If another heat source is used to heat the
cylinder and this is allowed to raise the water
temperature excessively then the overheat
thermostat will trip. This is likely on solar
thermal products when the solar thermostats
are set at high temperatures.

Thermostat Type TSE tted in the

E

L

Immersion Heater Wiring

Immersion Heaters

The immersion heaters tted to our units are 3kW 240V ~AC. Check that the mains
supply conforms to this, and all external wiring conforms to the most recent
revision of the IEE wiring regulations. An Incoloy element is used on this product for
standard domestic use and water conditions, use our Titanium elements in all other
circumstances, part number SH002.

The immersion heater is tted into the hot water cylinder using an O-ring. After the
unit is lled with water check for leaks to determine if the O-ring has sealed and
tighten carefully using the appropriate tool. To prevent damage to the O ring do not
use excessive force to tighten the immersion heater.

The immersion heater is supplied with a thermostat which has been tested
for operation in the cylinder and complies with the European directives for
Electromagnetic compatibility and radio interference. It is Rated at 16 Amp 250V ~AC.

N

indirect cylinders - is supplied set
in position 5 at 60°C ± 4°C.

When ordering a replacement
part the TSR thermostat type will
be supplied with the immersion
heater.

The Direct cylinder is intended to be heated
from an off peak supply using the lowest
immersion heater(s) and boosted via the upper
immersion heater from an on peak supply.
Suitable controllers are available to control this
operation eectively.

Solar Thermistors / sensors

Care must be taken to ensure that the solar probes
are fully inserted into the pockets provided.

Important

Failure to follow the drain down procedure will
invalidate the warranty. (see page 20)

NEVER drain the cylinder of hot water and

then close all cylinder inlets and
outlets.

REASON as the air remaining in the cylinder

cools the pressure inside the
cylinder will fall below atmospheric
and cause damage to the cylinder.

NEVER close the cold main and drain the

cylinder via any tap connected to it.

REASON as the water drains, the pressure

inside the cylinder may decrease
below atmospheric and this may
cause damage to the cylinder.

In line with good plumbing practice, use of
excessive ux should be avoided.

INSTALLATION

Page 14

INSTALLATION

Warming/Overflow

Pipe

Minimum
distance as
required by

boiler

manufacturers

instructions

Boiler

Schematic Open Vented Primary System

F & E Cistern

Motorised Valve

(Energy cut-out)

Gate Valve

(Not supplied)

Motorised Valve

Pump

150mm max.

(Not supplied)

Schematic Sealed Primary System

Heating/primary Systems

The boiler and primary/heating systems should
be sized and installed in accordance with BS
EN 12828:2003, BS EN 12831:2003 & BS EN
14336:2004.

Safety

qSpa is tted with a Combined Temperature/
Pressure Relief Valve to cope with any increase
in system temperature and pressure above the
design limitations, when used with boilers up
to 45kW output, which is the maximum allowed
by section G3 of the Building Regulations.
The primary water temperatures should be
controlled as outlined below.

Primary Circuit

It is essential that the circuit between the boiler
and the qSpa is pumped. The motorised zone
valve supplied should be tted adjacent to the
unit and controlled by the cylinder thermostat
supplied. The thermostat and motorised valve
must be wired so that they both switch off
should an overheat situation develop. When
wiring the supplied components, it is important
to follow the wiring diagram in the Wiring
Section of these instructions.

Safety Valve

Boiler

Gate Valve

(Not supplied)

Expansion

Vessel

Gauge

Pump

Motorised Valve
(Energy cut-out)

Motorised Valve

(Not supplied)

Sealed Primary Circuit

Any boiler used must be tted with an over
temperature cut-out. Unvented primary circuits
may be filled or replenished by means of a
temporary connection between the circuit and
a supply pipe provided a ‘Listed’ double check
valve or some other no less eective backow
prevention device is permanently connected
at the inlet to the circuit and the temporary
connection is removed after use.

Alternatively, a CA device can be used, which
will allow the system to be permanently
connected to the cold mains supply. The
primary system can then be topped up, when
required, in the same way as an open vented
system tted with an F&E Cistern.

Gate Valve

All our cylinders are tested to BS EN 12897 at 15
l/mim.

In extreme situations where excessive flow
rates, above 25 l/min are present, then a gate
valve on the return from the cylinder to the
boiler, before it joins the central heating return,
may be required to reduce excessive ow rates
and therefore any potential noise problems.

Page 15

INSTALLATION

INSTALLATION

Motorised Valve

Energy cut-out

(Not supplied)

Schematic Solar Indirect System

Motorised Valve

Energy cut-out

(Not supplied)

Solar Panel

Solar

Controller

Expansion

Vessel

Solar Pumping Station

All components in a solar primary system must
be marked or identiable in such a way that
their design pressure and temperature can be
readily determined.

A pressure relief valve to control the risk of
over-pressure in system components should
be tted. A termination from a pressure relief
valve should minimise the risk of damage to
persons or materials. Suitable locations are
into a high temperature receptacle, an internal
gully or externally at ground level. High level
termination from walls or on roofs could cause
injury to people or animals below if the valve
were to release scalding water and steam.

The pipe leading to the safety device and the
collector should be of rigid and non-deformable
construction, without any possibility of
restriction or closure by any other fitted
component.

A more detailed diagram of our recommended
arrangement for a typical solar system is shown
on page 18.

This provides all the necessary controls and
safety devices necessary for the solar system i.e.
the two port zone valve is wired as an energy
cut out and the pump/valve will only allow heat
transfer as required under control of the solar
controller.

The solar pocket provided accommodates an
8mm diameter sensor which, with the sensor
located in the solar collector (or in the ow
pipe immediately adjacent to the collector),
will provide the information required by the
solar controller.

Note: If the motorised valve is not used then
any factory built hydraulic station for solar
use MUST be tted with suitable non-return
valves in both flow and return pipes to
prevent gravity circulation when the pump
is not running.

If there is a possibility of the solar controller that
you install causing the cylinder temperature to
exceed 80°C, under normal working conditions,
then a Solar tempering valve must be tted to
the domestic hot water outlet of the cylinder.
This must limit the hot water temperature to a
maximum of 60°C.(ref building regulations part
G3 3.63). Suitable plumbing congurations for
installing this valve are shown on page 17 of this
manual. NB. Any tted Overheat thermostats
may require resetting in the winter months to
enable backup heat sources to heat the cylinder.

INSTALLATION

Page 16

INSTALLATION

✗

Figure 1: Cold port of the blending valve connected to mains supply

NOT ALLOWED

Mixed HW out

Mains CW in

Figure 2: Cold port of the blending valve connected to balanced cold

supply - NON-RETURN VALVE MUST BE FITTED

Mixed HW out

Non-Return Valve (must be fitted)

Balanced cold feed

Mains CW in

Fitting Blending Valves To The Unvented
qSpa Appliances

When tting a blending valve to the unvented
appliances, it is important that the installation
does not contravene the G3, WRC and Health
and Safety directives or the manufacturers
recommendations. If this is the case, then
the warranty should be null & void. The key
requirements to comply with these regulations
are: -

1. Any fitting or material in contact with
potable water (e.g. a blending valve) must
be approved by WRC or an equivalent body.

2. Connections or wiring arrangements must
not bypass any safety devices.

3. Any expansion due to heating must not be
allowed to expand back into the cold mains.

4. The settings of any safety devices must not
be tampered with or adjusted.

The diagrams opposite shows how the
blending valve can be piped onsite.

Figure 1 shows the cold water port of the
blending valve connected to the mains cold
water supply before the inlet control group.
This arrangement is completely unacceptable
and illegal because: -

• the water is allowed to expand in to mains
cold water supply.

• the vessel will be charged to the incoming
mains supply which may be considerably
higher than the working pressure of the
vessel.

If this arrangement is used then the Keston
Heating warranty will not be valid.

Figure 3: Cold port of the blending valve connected to mains supply

to the vessel after the inlet control group

Mixed HW out

Balanced cold feed

Mains CW in

Page 17

Figure 2 shows the cold water port of the
blending valve connected to the balanced
cold water outlet. This arrangement will only
be acceptable if a WRAS approved non-return
valve is tted, otherwise: -

• during the heating cycle, the water will
expand back into the mains supply, as the
regulating valve must not be relied upon
to act as a check valve under all operating
conditions.

• depending upon the characteristics of the
blending valve, hot water may also ow from
the balanced cold water taps.

Figure 3 shows the cold port of the blending
valve connected to the cold water supply to the
vessel after the inlet control group. This should
be the preferred method. It is recommended
that the installer should ensure that there is no
gravity circulation in the pipework connected to
the cold port. If necessary, this can be achieved
by tting a non-return valve or using a thermal
trap.

INSTALLATION

INSTALLATION

Schematic Showing Solar Wiring Requirements

Solar Controller

S1

S1

No isolation valve
should be installed
between the solar
circuit and the safety
valve (pressure relief
valve)

1 bar

Pressure
Relief Valve

S1 S2 S3

1 2 3 4 5 6 7 8

Unvented Cylinder

Anti Gravity

Solar

T

T

Check Valve

Pumping
Station

LNR1R2 NN

201918171615141312

Anti Gravity
Check Valve

Dual Thermostat

o

+ C

o

+ C

TWO PORT

2 1

C

1

2

C

ZONE VALVE

(Not
supplied)

A

B

Solar Coil

This valve must be tted on

the return to the solar panels

and be suitable for higher

temperatures operation

INSTALLATION

1 98765432 10

L N

230 VAC 5 amp
Mains Supply

Page 18

Standard 10 way
wiring junction box
(Not supplied)

1 98765432 10

11

12

N L 1 2 3 4

OFF ON OFF ON

HW CH

1 2 3 4

Room ThermostatCentral Heating Control

L

N

E

Mains Supply
Fed Via Double
Pole Isolator
230 VAC ~ 5 Amps

Danfoss
WB12
Wiring
Centre

HTG
VALVE

HW
VALVE

Typical schematic wiring diagram for an unvented installation

The electrical installation must
comply with IEE requirements.

For electrical installation

refer to BS7671

Note: Do not attempt

the electrical work unless

you are competent to carry

out to the above standard

BlueBl

BrownBr

Green

Grey

Green / Yellow

G

Gr

G/Y

WIRE COLOUR LEGEND

Black

Orange

Yellow

White

Red

B

Or

Y

Wh

R

Br Bl G/Y Br Br Bl G/Y

Or

Gr

5 Amps

Br Bl

G/Y

Br Br B

*Br

Bl

G/Y

Br

B

Bl Br Br Br

Br Bl B

G/Y

* Blue core used
from standard 3 core
flex please ensure you
use brown sleeving at
both terminating ends
to identify core potential.

4 core cable

L N

L

L_P

SL_B

ENN_P

E_P

Br Bl G/Y B Br Bl G/Y

Boiler
Pump

ISSUE No : 5

APPROVED

DRN.

DATE

07-12-10

N. Fursman

V4043A
TWO PORT
ZONE VALVE

A

B

HTG

Br Bl G/Y

OrGr

V4043A
TWO PORT
ZONE VALVE

A

B

DHW

Br Bl G/Y Or Gr

GAS BOILER

Boiler Permanent Live

Boiler Neutral

Boiler Earth

Boiler Switch Live Demand

Boiler Controlled Pump

Provide extra core
from terminal 12 to
L-P connection on
the boiler (shown
dotted) and remove
the boiler pump link
if the boiler has an
independant
pump output.

L

N

E

(S-PLAN) WIRING DIAGRAM WITH TWO 2 PORT VALVES AND BOILER CONTROLLED PUMP OVERRUN OPTION

Br Bl G/Y

B

Br

Or

ELECTRONICS

1

C

2

1

C

2

Dual Cylinder Stat

Overheat Stat

Spade

connectors

required
for earth

connections

Control Stat

G/Y Br

R (Supplied with stat)

*BrB

4 core cable

1 98765432 10

11

12

N L 1 2 3 4

OFF ON OFF ON

HW CH

1 2 3 4

Room ThermostatCentral Heating Control

1

C

2

1

C

2

Dual Cylinder Stat

Overheat Stat

Spade

connectors

required
for earth

connections

Control Stat

L

N

E

Mains Supply
Fed Via Double
Pole Isolator
230 VAC ~ 5 Amps

HTG
VALVE

HW
VALVE

Typical schematic wiring diagram for an unvented installation

The electrical installation must
comply with IEE requirements.

For electrical installation

refer to BS7671

Note: Do not attempt

the electrical work unless

you are competent to carry

out to the above standard

BlueBl

BrownBr

Green

Grey

Green / Yellow

G

Gr

G/Y

WIRE COLOUR LEGEND

Black

Orange

Yellow

White

Red

B

Or

Y

Wh

R

Br Bl G/Y Wh Br BrBl G/Y

Or B

Gr Gr

5 Amps

Br Bl

G/Y

Br Br B

*Br

Bl

G/Y

Bl Br Br Br

Br Bl B

G/Y

G/Y Br

R (Supplied with stat)

*BrB

* Blue core used
from standard 3 core
flex please ensure you
use brown sleeving at
both terminating ends
to identify core potential.

4 core cable

4 core cable

L N

L

L_P

SL_B

ENN_P

E_P

Br Bl G/Y B Br Bl G/Y

Boiler
Pump

ISSUE No : 4

APPROVED

DRN.

DATE

07-12-10

N. Fursman

A

B

HTG

Wh Bl G/Y

OrGr

A

B

DHW

Br Bl G/Y Or Gr

GAS BOILER

Boiler Permanent Live

Boiler Neutral

Boiler Earth

Boiler Switch Live Demand

Boiler Controlled Pump

Provide extra core
from terminal 12 to
L-P connection on
the boiler (shown
dotted) and remove
the boiler pump link
if the boiler has an
independant
pump output.

L

N

E

(Y-PLAN) WIRING DIAGRAM WITH 3 PORT VALVE/2 PORT SAFETY VALVE AND BOILER CONTROLLED PUMP OVERRUN OPTION

Br Bl G/Y

B

B

Br

Or

ELECTRONICS

13

V4073A

MID POSITION

ZONE VALVE

V4043A

TWO PORT

ZONE VALVE

INSTALLATION

Page 19

INSTALLATION

INSTALLATION

Connections can come loose in transit, and all should be checked before installation.

The 90 degree elbow tted on the hot draw o needs to be positioned and tightened
by installer.

The control thermostat for indirect heat exchanger heat up of our cylinders are usually
set at between 60°C - 65°C. During commissioning the actual temperature that the
cylinder reaches when the thermostat(s) operate should be tested and adjusted so
that it achieves a minimum of 60°C. This temperature needs to be achieved on a
regular basis.

Check the pressure on the air side of the expansion vessel = 3 bar. This must be done
when the water in the cylinder is free to expand in atmospheric pressure or the cylinder
and relevant pipe work is empty.

Check that the drain cock is closed, and open all the cold and hot water taps and other
terminal ttings. Allow the system to ll with water, and to run until there is no air left
in the system. Close the taps and inspect the system closely for leaks.

Manually open the Relief Valves one by one and check that water is discharged and
run freely through the tundish and out at the discharge point. The pipework should
accept full bore discharge without overowing at the tundish, and the valve should
seat satisfactorily.

In line with good plumbing practice, use of excessive ux should be avoided. When
soldering above the cylinder, ensure ux/solder does not contaminate the cylinder
below, since this can cause corrosion. Flushing should be done performed as per BS
EN 806:4 2010 section 6.2.

Allow the cylinder to heat to normal working temperature, then thoroughly ush the
domestic hot and cold water pipework through each tap.

NOTE: If this appliance is to be installed in other than a single domestic dwelling ie. in
an apartment block or student ats etc., the hot and cold water system will need to be
disinfected in accordance with BS EB 806:4 2010 section 6.3 and the Water Regulations.

caused through a failure to do this adequately
will not be covered by the warranty.

For the reasons mentioned, we recommend the
use of a non chlorine based disinfectant such as
Fernox LP Sterox as manufactured by Cookson
Electronics when carrying out disinfection of
systems incorporating these appliances.

Remove the lter from the combination inlet
group clean and replace. Rell the system and
open all hot taps until there is no air in the pipe
work. ENSURE CYLINDER IS DRAINED PRIOR

TO CHECKING OR REMOVING FILTER FROM
THE COMBINATION INLET GROUP.

Allow the cylinder to heat to normal working
temperature with whatever heat source is to be
used, and check again for leaks. The pressure
relief valve or the P&T valve should not operate
during the heating cycle. If the P&T valve
operates before the pressure relief valve due to
high pressure, check that the inlet control group
is tted correctly, and no valve is between the
inlet control group and the cylinder.

The boiler/heating systems should be lled and
commissioned in accordance with good practice
following the guidance in BS 7593:2006/the
boiler manufacturers instructions. This includes
adequately ushing the system to remove any
debris that may have been introduced during
installation/maintenance.

NOTE

Because the qSpa appliance is stainless steel, the use of chlorine as the disinfection
agent can cause damage unless the appliance is adequately ushed and relled with
the mains water immediately on completion of the disinfection procedure. Damage

IMPORTANT - DRAIN DOWN PROCEDURE

1 Switch o both the boiler and the immersion heater

2 Open the nearest hot tap and run all hot water until cold, then close it

3 Close the incoming cold main at the stop tap

4 Hold open the pressure and temperature relief valve until water stops

discharging into the tundish and leave it open

5 Open the cold taps starting from the highest point and working down to

the lowest tap, leaving them open

6 When the cold taps have stopped draining, open the hot taps starting from

the highest and working down to the lowest tap

7 Open the drain cock and ensure the pressure and temperature relief valve

is held open until the cylinder is empty

At the time of commissioning, complete all
relevant sections of the Benchmark Checklist
located on the inside back pages of this
document.

This must be completed during commissioning
and left with the product to meet the Warranty
conditions oered by Keston Heating.

COMMISSIONING

Page 20

SERVICING AND MAINTENANCE

The Registered Installer is responsible for the safe installation and operation of the
system. The installer must also make his customer aware that periodic maintenance
of the equipment is essential for safety.

Maintenance periods will vary for many reasons. Keston Heating recommend a
maximum of 12 months to coincide with boiler maintenance. Experience of local
water conditions may indicate that more frequent maintenance is desirable, eg, when
water is particularly hard, scale-forming or where the water supply contains a high
proportion of solids, eg, sand. Maintenance must include the following:

1. Check and clean lter

2. Manually check the operation of the temperature relief valve.

3. Manually check the operation of the expansion relief valve.

4. Check discharge pipes from temperature and expansion relief valves are free from
obstruction and blockage and are not passing any water.

5. Check the condition and if necessary descale the heat exchangers in hard water
areas.

6. Check that water pressure downstream of pressure reducing valve is within the
manufacturers limits.

7. Check operation of motorised valve.

8. Check the pressure on the air side of the expansion vessel. This must be done with
the pressure on the water side at zero (gauge pressure).

9. Check and advise the householder not to place any clothing or other combustible
materials against or on top of this appliance.

10. On completion of the work, ll in the Benchmark Service Record towards the back
of this manual.

IMPORTANT NOTE

When draining down the appliance for any reason, the instructions
provided in the Commissioning Section (Page 20) MUST be followed to
prevent potential damage to the cylinder.

After servicing, complete the relevant Service Interval Record section of the Benchmark
Checklist located inside this document.

Page 21

SERVICING AND MAINTENANCE

SERVICING AND MAINTENANCE

Scale

In hard water areas it is recommended that an in-line scale inhibitor is tted. Reducing
the temperature of the stored water will reduce the rate at which scale forms. If the
recovery rate is badly aected, this is an indication that scaling may have occurred.
In this event, follow the procedures as recommended by a reputable Water Treatment
Company.

General

No water at the tap. Check that the mains water supply is turned ON. Check the line
strainer is not blocked. Check that the combination valve has been tted so that water
is owing in the correct direction.
If the water at the tap is cold, ensure that the boiler has been switched ON and is
working correctly. Check that there are no air locks in the primary system. ISOLATE
THE UNIT AT THE MAINS ELECTRIC SUPPLY AND THEN CHECK THE FOLLOWING:
i. The cylinder thermostat
ii. The thermal cut-out, which can be re-set by pushing the red button
iii. The motorised valve
iv. The boiler thermostat
v. The boiler thermostat cut-out (if tted)

ANY ENERGY CUT-OUT MUST NEVER BE BY-PASSED UNDER ANY CIRCUMSTANCES.

If the units are not getting hot and the heat source is electrical, ensure that the
immersion heaters are isolated from the mains before re-setting the energy cut-out.
If the immersion heater(s) need replacing this should be done with the units supplied
from Keston Heating.

Discharge From Relief Valves

If cold water is discharging from the expansion relief valve into the tundish check the
pressure on the expansion vessel when cold and recharge if necessary.

If the fault continues and the problem cannot be stopped by operating the easing
control a few times then either the Pressure Reducing Valve or the Relief Valve may
be at fault. If the cold water pressure is too high, this would suggest that the Pressure
Reducing Valve is at fault and the Keston Heating approved replacement should be
tted. If the pressure is correct then the Relief Valve will require replacing with a
Keston Heating approved component.

See Commissioning for drain down procedure.

If there is an overheat fault and very hot water is being discharged, turn o the heat
source, but not the water supply.

When the supply is cool, check thermostats and energy cut-outs in the boiler and
immersion heaters and replace the faulty component with one supplied by Keston
Heating and check that it works correctly before returning the system to full operation.

FAULT FINDING

Page 22

SERVICING AND MAINTENANCE

START

YES

Is boiler on?

YES

Is hot water programmer

in ‘on’ position?

YES

Is zone valve in

correct position?

YES

Is control temperature

set at 60ºC - 65ºC?

YES

Has high limit cut out?

NO

NO

NO

NO

NO NO

Switch on

Set programmer

Re-set, check wiring &

plumbing is correct

Re-set

Is all wiring to the

controls ok?

FAULT - No Hot Water (Indirect)

Re-wire

YES

Re-set

END

NO

YES

Replace thermostat

Page 23

FAULT FINDING

SERVICING AND MAINTENANCE

FAULT - Poor Water Flow at Hot Taps

START

YES

Is incoming mains supply
flow/pressure adequate?

YES

Is in-line strainer

(in combination valve)

clean?

YES

Is pressure reducing valve

(in combination valve)

working?

YES

Is system free from

restrictions/blockages?

YES

NO

NO

NO

NO

Water service check by

supply company required

Clean or replace strainer

as appropriate

Service /replace PRV

as appropriate

Clear obstructions

START

Is pressure downstream

of pressure reducing valve

NO

correct?

YES

Is valve seal and seat
clean & undamaged?

YES

Is heater operating at

less than 60ºC?

NO

Re-set temperature

END

NO

YES

charge pressure correct?

Clean or replace

as required

Is expansion vessel

YES

Replace ERV/TPRV

NO

YES

Recommission

expansion

vessel pressure

Is ERV/TPRV

discharging?

NO

FAULT - Water Discharge Into Tundish

FAULT FINDING

Replace PRV END

Page 24

SERVICING AND MAINTENANCE

SPARE PARTS LIST

Description Quantity Stock Code No.

1 3kW immersion element 1 176749

2 22mm 90° compression elbow c/w/drain 1

3 Pressure and temperature relief valve 6 bar 89-96°C 1 176748

4 Inlet group set at 3 bar c/w expansion relief valve set at 4.5 bar 1 176750

5 ¾” exible hose 1 176755

7 12 litre expansion vessel 1 176751

8 18 litre expansion vessel 1 176752

9 24 litre expansion vessel 1 176753

10 35 litre expansion vessel 1 176754

12 22mm 2 port valve (indirects only) 1 176758

13 Junction wiring box (12 way) 1 176759

14 Control and overheat limit thermostat 1 176757

15 15mm x 22mm tundish 1 176756

Page 25

SHORT PARTS LIST

Description

Manual handling means any transporting or supporting of a load (including lifting,
putting down, pushing, pulling, carrying or moving) by hand or bodily force.

Scope

This assessment will cover the largest unit within each product range.

For specic weights and dimensions please refer to technical data section.

Main Hazards

Vision may not be clear due to the size of the products.
Adopting an incorrect method of lifting may cause injury, attempting to lift these
products will require help from others. (Team lifts)

Control Measures

Manual lifting procedure

The lift, key factors in safe lifting are:

a. Balance
b. Position of back
c. Positioning of the arms and body
d. The hold
e. Taking the lead for team lifts

a. Balance - Since balance depends essentially upon the position of the feet,

they should be apart about hip breadth with one foot advanced giving full
balance sideways and forward without tension. In taking up this position,
lifting is done by bending at the knees instead of the hips and the muscles
that are brought into use are those of the thigh and not the back.

b. Position of back - Straight - not necessary vertical. The spine must be

kept rigid, this coupled with a bent knee position, allows the centre line of
gravity of the body to be over the weight so reducing strain.

c. Positioning of arms and body - The further arms are away from the side,

the greater the strain on the shoulders, chest and back. Keep elbows close
to the body arms should be straight.

d. The hold - Before lifting ensure you have a good hold.

e. Taking the lead for team lifts- As

more than one person is required
for these products ensure that one
person is taking the lead. This may
be you so ensure that each person
that is helping is made aware of the
weight and of the items listed within
this assessment. Make sure you and
any others helping know the route
you intend to take that it is clear of
any obstructions. Never jerk the load
as this will add a little extra force and
can cause severe strain to the arms,
back and shoulders. If there are steps
involved decide on where you will
stop and take a rest period. Move
smoothly and in unison taking care
to look and listen to others helping
with the lift. Where possible use
a sack truck to move the product
over long at distances, only lift the
products when necessary. If in doubt
stop and get more help.

Individual capability

Individual capability plays an important
part in handling these products. Persons
above average build and strength will
nd it easier and should be in good
health. Persons below average build and
strength may require more rest periods
during the handling process.

Pregnant women should not carry out
this operation.

Persons who are not in good health
should seek medical advice prior to
commencing any lifting or manual
handling operation.

Residual risk

Following the guidelines given above will
reduce any risk to injury.

All persons carrying out this operation
must be fully trained and copies of the
specic risk assessment made available
for inspection and use in their training
process.

Further guidance on Manual Handling
can be obtained from the Health and
Safety Executive. Manual Handling
Operations Regulations 1992 (amended
by Health and Safety (Miscellaneous
Amendments) Regulations 2002.

MANUAL HANDLING OF APPLIANCE PRODUCTS

APPENDIX

APPENDIX

Page 26

TERMS AND CONDITIONS

COMPANY LIABILITY AND GUARANTEE

1. Subject to the terms of these Conditions of Sale and Guarantee Terms Keston Heating provide Guarantees in respect of specic products as

set out in this clause.

2. Each Guarantee is strictly conditional upon the following:-

2.1. Complaints must be given to us immediately, before any action is taken, as responsibility cannot be accepted if repairs or renewals are

attempted on site without our written approval.

2.2. The unit has been installed in accordance with our installation and service instructions and all relevant codes of practice and regulations in

force at the time of installation.

2.3. All necessary inlet controls and safety valves have been tted correctly.

2.4. The unit has only been used for the storage of potable water supplied from the public mains. The water quality shall be in accordance with

European Council Directive 98/83 EC, or revised version at the date of installation, and is not fed with water from a private supply. Particular:

Chloride content: Max. 200 mg/l

Sulphate content: Max. 200 mg/l
Combination chloride/sulphate: Max. 300 mg/l (in total)

2.5 Where appropriate the unit has been regularly maintained as detailed in the installation and service instructions

2.6. Defects caused by corrosion or scale deposits are not covered by any Guarantee.

2.7. Where we agree to rectify any defect we reserve the right to undertake the work on our own premises.

2.8. We will not accept any labour charges associated with replacing the unit or parts for any of the following products listed.

2.9. If the newly tted water heater is not in regular use then it must be ushed through with fresh water for at least 15 minutes. Open at least

one hot water tap once per week, during a period of at least 4 weeks.

3. Guarantees are provided in respect of specied goods supplied by Keston Heating as follows:-

(a) Domestic and Commercial Open Vented Cylinders and Tanks.

The storage vessel is guaranteed for ten years and if it proves to be defective either in materials or workmanship, we will either repair or

supply replacement at our option with the closest substitute in the case of any obsolete product to any address in Great Britain.

(i) free of all charge during the rst year after delivery by us.

(ii) thereafter at a charge of one-tenth of the then current list price and any copper price supplement and delivery charge during the second

year after delivery by us and increasing by a further one-tenth on the second and subsequent anniversary of delivery by us.

(b) Unvented Cylinders

Keston Heating guarantee the components including controls, valves and electrical parts for two years from the date of purchase. IT SHOULD

BE NOTED THAT THE FACTORY FITTED TEMPERATURE AND PRESSURE RELIEF VALVE MUST NOT BE REMOVED OR ALTERED IN ANY WAY OR
THE GUARANTEE WILL NOT BE VALID. KESTON HEATING WILL NOT BE RESPONSIBLE FOR ANY CONSEQUENTIAL LOSS OR DAMAGE HOWEVER
IT IS CAUSED.

The guarantee for the stainless steel vessel is for twenty ve years against material defect or manufacturing faults if the original unit is

returned to us AND PROVIDED THAT:

(i) It has not been modied, other than by Keston Heating.

(ii) It has not been subjected to wrong or improper use or left uncared for.

(iii) It has only been used for the storage of potable water supplied from the public mains, max 200mg/litre chloride.

(iv) It has not been subjected to frost damage.

(v) The benchmark service record is completed after each annual service.

(vi) The unit has been serviced annually.

(vii) Any disinfection has been carried out strictly in accordance with BS6700.

If the stainless steel vessel proves to be defective either in materials or workmanship we reserve the right to either repair or supply

replacements or the closest possible substitute in the case of any obsolete product and will collect and deliver to any address in England,
Scotland and Wales (excluding all islands):

(i) free of charge during the rst year after delivery by us.

(ii) thereafter at a charge of one twenty fth of the then current list price during the second year after delivery by us and increasing by a

further one twenty fth on the second and subsequent anniversary of delivery by us.

ACTION IN THE EVENT OF FAILURE

We will require the return of a cylinder which develops a leak for inspection. If our examination conrms a failure then an appropriate level of

credit against the cost of the original cylinder will be issued in line with the terms of our warranty.

Please note:

- Installation must have been carried out by a licensed specialized company (heating contractor or plumber) following the version of
installation instructions in force.

- Keston Heating or its representative was given the opportunity to check complaints on site immediately after any defect occurred.

- Conrmation exists that the system was commissioned properly and that the system was checked and maintenance was performed
annually by a specialised company licensed for this purpose.

Page 27

TERMS AND CONDITIONS

Page 28

Page 29

MAINS PRESSURE HOT WATER STORAGE SYSTEM COMMISSIONING CHECKLIST

This Commissioning Checklist is to be completed in full by the competent person who commissioned the storage system as a means of
demonstrating compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.

Failure to install and commission this equipment to the manufacturer’s instructions may invalidate the warranty but does not affect statutory rights.

MAINS PRESSURE HOT WATER STORAGE SYSTEM COMMISSIONING CHECKLIST

Customer name: Telephone number:

Address:

Cylinder Make and Model

Cylinder Serial Number

Commissioned by (PRINT NAME): Registered Operative ID Number

Company name: Telephone number:

Company address:

Commissioning date:

To be completed by the customer on receipt of a Building Regulations Compliance Certicate*:

Building Regulations Notication Number (if applicable)

ALL SYSTEMS PRIMARY SETTINGS (indirect heating only)

Is the primary circuit a sealed or open vented system? Sealed Open

What is the maximum primary ow temperature? °C

ALL SYSTEMS

What is the incoming static cold water pressure at the inlet to the system? bar

Has a strainer been cleaned of installation debris (if tted)? Yes No

Is the installation in a hard water area (above 200ppm)? Yes No

If yes, has a water scale reducer been tted? Yes No

What type of scale reducer has been tted?

What is the hot water thermostat set temperature? °C

What is the maximum hot water ow rate at set thermostat temperature (measured at high ow outlet)? I/min

Time and temperature controls have been tted in compliance with Part L of the Building Regulations? Yes

Type of control system (if applicable) Y Plan S Plan Other

Is the cylinder solar (or other renewable) compatible? Yes No

What is the hot water temperature at the nearest outlet? °C

All appropriate pipes have been insulated up to 1 metre or the point where they become concealed Yes

UNVENTED SYSTEMS ONLY

Where is the pressure reducing valve situated (if tted)?

What is the pressure reducing valve setting? bar

Has a combined temperature and pressure relief valve and expansion valve been tted and discharge tested? Ye s No

The tundish and discharge pipework have been connected and terminated to Part G of the Building Regulations Yes

Are all energy sources tted with a cut out device? Yes No

Has the expansion vessel or internal air space been checked? Yes No

THERMAL STORES ONLY

What store temperature is achievable? °C

What is the maximum hot water temperature? °C

ALL INSTALLATIONS

The hot water system complies with the appropriate Building Regulations Yes

The system has been installed and commissioned in accordance with the manufacturer’s instructions Yes

The system controls have been demonstrated to and understood by the customer Yes

The manufacturer’s literature, including Benchmark Checklist and Service Record, has been explained and left with the customer Yes

Commissioning Engineer’s Signature

Customer’s Signature

(To conrm satisfactory demonstration and receipt of manufacturer’s literature)

This Commissioning Checklist is to be completed in full by the competent person who commissioned the storage system as a means of
demonstrating compliance with the appropriate Building Regulations and then handed to the customer to keep for future reference.

Failure to install and commission this equipment to the manufacturer’s instructions may invalidate the warranty but does not affect statutory rights.

Customer name: Telephone number:

Address:

Cylinder Make and Model

Cylinder Serial Number

Commissioned by (PRINT NAME): Registered Operative ID Number

Company name: Telephone number:

Company address:

Commissioning date:

To be completed by the customer on receipt of a Building Regulations Compliance Certicate*:

Building Regulations Notication Number (if applicable)

ALL SYSTEMS PRIMARY SETTINGS (indirect heating only)

Is the primary circuit a sealed or open vented system? Sealed Open

What is the maximum primary ow temperature? °C

ALL SYSTEMS

What is the incoming static cold water pressure at the inlet to the system? bar

Has a strainer been cleaned of installation debris (if tted)? Yes No

Is the installation in a hard water area (above 200ppm)? Yes No

If yes, has a water scale reducer been tted? Yes No

What type of scale reducer has been tted?

What is the hot water thermostat set temperature? °C

What is the maximum hot water ow rate at set thermostat temperature (measured at high ow outlet)? I/min

Time and temperature controls have been tted in compliance with Part L of the Building Regulations? Yes

Type of control system (if applicable) Y Plan S Plan Other

Is the cylinder solar (or other renewable) compatible? Yes No

What is the hot water temperature at the nearest outlet? °C

All appropriate pipes have been insulated up to 1 metre or the point where they become concealed Yes

UNVENTED SYSTEMS ONLY

Where is the pressure reducing valve situated (if tted)?

What is the pressure reducing valve setting? bar

Has a combined temperature and pressure relief valve and expansion valve been tted and discharge tested? Ye s No

The tundish and discharge pipework have been connected and terminated to Part G of the Building Regulations Yes

Are all energy sources tted with a cut out device? Yes No

Has the expansion vessel or internal air space been checked? Yes No

THERMAL STORES ONLY

What store temperature is achievable? °C

What is the maximum hot water temperature? °C

ALL INSTALLATIONS

The hot water system complies with the appropriate Building Regulations Yes

The system has been installed and commissioned in accordance with the manufacturer’s instructions Yes

The system controls have been demonstrated to and understood by the customer Yes

The manufacturer’s literature, including Benchmark Checklist and Service Record, has been explained and left with the customer Yes

Commissioning Engineer’s Signature

Customer’s Signature

(To conrm satisfactory demonstration and receipt of manufacturer’s literature)

* All installations in England and Wales must be notied to Local Authority Building Control (LABC) either directly or through a

Competent Persons Scheme. A Building Regulations Compliance Certicate will then be issued to the customer.

© Heating and Hotwater Industry Council (HHIC)

www.centralheating.co.uk

While this Checklist can be used for any installation covered by its description, only appliances manufactured by Scheme Members will
be covered by the rules and requirements of the Benchmark Scheme.

BENCHMARK

Page 30

SERVICE RECORD

It is recommended that your hot water system is serviced regularly and that the appropriate Service Record is completed.

Service Provider

Before completing the appropriate Service Record below, please ensure you have carried out the service as described in the manufacturer’s instructions.

SERVICE 01

Engineer name:

Company name:

Telephone No:

Comments:

Signature

SERVICE 03

Engineer name:

Company name:

Telephone No:

Comments:

Signature

SERVICE 05

Engineer name:

Company name:

Telephone No:

Comments:

Date:

Date:

Date:

SERVICE 02

Engineer name:

Company name:

Telephone No:

Comments:

Signature

SERVICE 04

Engineer name:

Company name:

Telephone No:

Comments:

Signature

SERVICE 06

Engineer name:

Company name:

Telephone No:

Comments:

Date:

Date:

Date:

Signature

SERVICE 07

Engineer name:

Company name:

Telephone No:

Comments:

Signature

SERVICE 09

Engineer name:

Company name:

Telephone No:

Comments:

Signature

Date:

Date:

Signature

SERVICE 08

Engineer name:

Company name:

Telephone No:

Comments:

Signature

SERVICE 10

Engineer name:

Company name:

Telephone No:

Comments:

Signature

Date:

Date:

Page 31

BENCHMARK

Keston Heating. pursues a policy of continuing improvement in the design and performance of its products.

The right is therefore reserved to vary specification without notice.

Keston Heating.,

Keston

PO Box 103, National Avenue, Kingston Upon Hull, HU5 4JN

Tel [phone] Fax [phone]

Registration No. London 322 137

Helpline: 01482 443005

www.keston.co.uk