Keston Spa 120 litre User manual

KESTON SPA
UNVENTED STORAGE CYLINDERS
SINGLE ANDTWIN COIL MODELS
lnsta llation lnstructions
&
Perfo rma nce Specification
Fully Approved To Building Regulations G3 and L
WRAS Approved to theWater Regulations
KESTON BOILERS LTD
34 WEST COMMON ROAD
HAYES, BROMLEY
KENT BR2 7BX
Tel:[phone]
Fax[phone]
Email: [email protected]
Web: www.keston.co.uk
Single Coil Models
Spa 120 litre
Spa 150 litre
Spa 210 litre
Spa 300 litre
Twin Coil Models
SpaTwin 210
SpaTwin 300
lndirect
Stainless Steel
Cylinders with
Ultra-High
Performance
lssue 04-2007
Specialists in high
Efficiency Commercial
& Domestic Heating
Equipment

READ CAREFU LLY BEFORE INSTALLATION
INCORRECT INSTALLATION MAY INVALIDATE GUARANTEE
CONTENTS
1. Component Check List
2. Handling and Storage
3. Location and Cylinder Mounting
4. Warnings
5. Markings and Specification
6. Connection Layout and Recommendations for
Pipework and Discharge Lines
7. Flushing and Commissioning
8. Electrical Specification and Wiring
g. SecondaryCirculation
10. Scale Advice and Maintenance
1 1. Trouble Shooting and Maintenance
12. Spares
13. Safety & Relevant British Standards
14. Tank Data Plate
Note to lnstaller: Please leave lnstallation manual with Householder after installation
PAGE
3
4
4
4
5
6
9
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10
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13
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14
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INTRODUCTION
The Keston Spa is a range of Duplex stainless steel un-vented water heaters with ultra high performance
coils for indirect heating.The use of stainless steel for both coil and iank ensures long lifJ and high
strength ensuring high pressure performance.The ultra high efficiency coils give rapid reheat and high
volume hot water delivery.
The units are supplied with manifold type pressure regulating/expansion relief valves preset to 3bar and
with integral strainer. However,the manifold can be separated to tlvo sections should you wish to install
the pressure regulating valve at a remote location. An expansion vessel is also suppliei for connection to
the cold supply. Use of an externat expansion vessel allows the entire volume of ihe tank to be used for
water storage.
The units are also fitted with a 3kW electric immersion heater as standby heating and adjustable
thermostat with overheat shut down to control the supply of indirect heat to thl unit.
EI
E
r
#
Operating Data:
Maximum Water Supply Pressure to pressure iegulating ralve
Operating Pressure of unit
Expansion Vessel Charge Pressure
Expansion Relief Valve Setting
Maximum Primary Working Pressure
Opening Temperature of T&P Valve
Opening Pressure ofT&P Valve
Performance Data:
Model Spa Spa i Spa Spa
't20 150 210 300
Re-heat 15C60C(approx) 23mins 25mins 35mins 44mins lSmins
Re-heat after 7006 draw-off l Tmins l Tmins 22 mins 2g mins 1l mins
(approx)
NB: Above figures assume constant primary coil flow of 82C and sufficient heat input to fully utilise
the coil output.5paTwin figures assume both coils used concurrently with sufficient boiler power
'1. ComponentCheck-List
The following items accompany your Spa Unvented Storage Cylinder.
Combined control and overheat
thermostat with manual cut-out
switch, variable thermostat
(30 -70C) and sensor.
90C/7 bar ?Temperature and
Pressure (T&P) relief valve
Discharge tundish
2-Port Motorised Valve Expansion vessel, hose and
wall mounting kit
12.0 bar
3.0 bar
3.0 bar
6.0 bar
3.5 bar
90c
7 bar
Spa Twin Spa Twin
210 300
22mins
14 mins
Combined strainer/pressure
reduction valve.3.0 bar, with stop
tap, check valve,expansion relief valve 6
bar.
3kW /230VAC electric element with safety
cut-out switch and variable thermostat -
1.75" BSP head
Diagnostic gauge
M
ry
w
@

Lpanslon
wlthWall
Eracket
Ssndary ktum Circult
(21o,250& 300 Lilzes Flexlble Ho*
Enhanced
Cold Conn*tbn
Handling & Storage
- Do not lift via valves or element bosses on unit
- Expansion vessels must not pe dented.
- Store unit away from excess heat or frost
- Always transport cylinders in the vertical position
Location and Cylinder Mounting
- Site the unit as close as possible to main points of usage. Outlets above the Spa
unit will reduce the outlet pressure by 0.1 bar for every 1m of height difference.
- Avoid locating the unit where freezing temperatures may be experienced.All
expose pipework should be insulated.
- Ensure unrestricted access to plumbing connections and top of expansion vessel
- Allow sufficient clearance for removal of immersion heater and valves.
- ln floor standing the unit place the unit on a load bearing surface sufficient for the
weight of the unit when full of water.
- The unit must be installed and transported vertically unless otherwise indicated on
packaging
- Valves can be mounted in any orientation provided discharge downpipes can be run
to drain in accordance with instructions (seeTundish).The discharge pipework
should have a minimum fall of 1:200 from the unit.
- A drainage safe tray should be placed under the cylinder to facilitate servicing
Warnings
- Boilers without thermostatic control,such as and steam heating plant should not be
used with this unit unless appropriate additional safety controls are installed. Solid
fuel boiler must not be used with any unvented unit.
- Under no circumstances must.the unit be filled or operated without the factory
fitted T&P relief valve.
I
- Do not fit a stop or check valve between the inlet safety group and the cylinder
- Do not apply heat to any component or any welding to cylinder or pipe connections.
- All electrical wiring should be carried out by a registered electrical contractor and
must conform to IEE Wiring Regulations.
- lf a replacement immersion heater is required at any time, do not fit an immersion
heate(s) without thermal cut-out(s).
- Ensure unit is flushed for 3 minutes via hot tap before switching on.
- Do not use excessive plumbers paste or flux, which may damage the controls'
- Do not swit{h on power until the unit is full of water. Do not open electric elements
unless power is switched off.
- Position discharge tundish away from any electrical components.
- Do not allow discharge pipes to kink or block in any way.
goller
Boller
Return
Non
Return
Bonze
Pump
lmmttlon
[hter

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Markings and Specification
Single Coil Spa
l/2'F PTRY Bo$
Sond
..__ llrwdon
H6ter .
(rct.lw.yr fitt€d,
sbbte)
t/2T Sbt 80s
' zmm Cold fed whh dtp
plpo to d.i€toa ln bottom
ofcyllnder
DIMENSIONS (in mm) IMM
ABCDEF
MODEL CAPACTY WEIGHT
(Litres) Empty Full Height Dia
(ks) (ks)
Spa 120 120 35 , : 155
Spa 150 150 40 . 190
Spa 210 2lO 50 260
Spa 300 3oo 60 360
906 550
1093 550
1469 5s0
2032 550
290
330
365
365
(kw)
3
'3
3
6
330
370
405
405
390 34s N/F N/F
465 385 N/F N/F
46s 465 N/F 11s0
465 660 1100 1600

Double CoilSpaTwin
l/2'F PTFw E6t
l/2'F Sbt 86s
,/
*
i s*nd"ty t"ru.
I {rct ,tmys Rn"a1
',
i!
, j* 22sm Cold H wlth dlp
Flpe b defldo. ln botum
ofcylhds
MODEL CAPACIIY WEIGHT
(Litres) Empty Full Heighr Dia
.(kst (ks)
SpaTwin2l0 210 55 265 1469 550
SpaTwin3@ 300 60 365 2032 550
DMENSIONS (in mm) IMM
ABCDEFGH(kW)
36s 420 779 834 lrso t268 46s 830 3
365 420 979 1034 1600 1832 465 1030 3

3.
14.
5.
6.
6. Connection Layout & Recommendations
The performance of any unvented mains fed cylinder is always limited by the supply of mains water to
the unit. A high static mains pressure is not a guarantee of adequate supply. The static mains supply
pressure should be measured as well as the size of tfue supply pipe. Unvented mains fed cylinders
should not be used where the water supplies have inadequate pressurg flow rate or where the supply
may be intermittent.
1 . For cylinder sizes up to 300 litres a suggested supply pressure of 1 bar or more is desirable.
2. For cylinders of 200 litres or below with water pressure below 1.5 bar use 22mm supply and
distribution pipework
Use 22mm pipe distribution up to the first branch connection
For 300 litres and over use 28mm or larger pipework lf long pipe runs are required extra
expansion vessel capacity may be necessary.
All hot pipework should be insulated.
Use the balanced cold take-off connectiori of the pressure reduction valve to ensure
satisfactory shower performance. However, it should be noted that this witl reduce the total
available regulated flow available from the tank
Do not vent the primary circuit from the boiler to the water heater system.
Better performance will be obtained by using 22mm pipe, limiting the number of elbows and
fittings and using swept bends.
Follow connection layout on page 3. Connect valves with flow in arrow direction marked on
valve bodies.
10. For indirect cylinders the control thermostat and overheat thermostat must be wired to the
Motorized valve supplied, or some other suitable device to shut off the flow to the coil that is
approved by a member of EOTA or by a body with NACCB accreditation.
1 1 . The high efficiency coil of the Spa tank offer a higher resistance to boiler water flow than
other lower efficiency traditional cylinders. Consideration should therefore be given to
additional pump capacity or a coil flow/return bypass arrangement. Such a by-pass may then
be adjusted to balance cylinder and boilpr flow accordingly. Refer to the cylinder coil pressure
drop curves below for pump selection. '
12. For twin coil models the boiler should be connected to the upper coil.The lower coil should
be used for the additional heat source, such as s6lar thermal or heat pump.
Coil Pressure Drop Curves
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Water FlowThrough Coil - Usec
f.i 0.8 0"9

How to drain the System
1. Switchofftheelectrical powertotheimmersionheate(s)andshutdowntheboiler.Closethestop
cock valve.
2. Open a hot water tap on order to reduce pressure in the cylinder. Leave the hot water tap open.
3. Connect a hose to the draining tap ensuring it reaches a level below the unit (this will ensuie a siphon
is established to drain the maximum amount of water) CAUTTON WATER DRATNED OFF MAy BE VERY HOTI
Discharge Pipework and Tundish
- Tundish must be visible
- Dischargepipemustbetofixedgratingandnotlocatedtocausepossibledischargeinjurytopersons.
Tvoical Discharoe Pioe Arranoement
Table 1: Sizing of copper discharge pipe D2 for common temperature relief valve outlet sizes.
Valve Min size Min size of Maximum resistance allowed Resistance created
outlet ofdischarge dischargepipe asalengthofstraightpipe byeachelbowor
Size pipe Dl D2 from tundish (i.e, no elbows or bends) bend
G1/2 l5mm 22mm
28mm
35mm
G3/4 22mm 28mm
35mm
42mm.
Gl 28mm 35mm
42mm
54mm
up to 9m
upto 18m
up to 27m
up to 9m
up to 18m
up to 27m
up to 9m
upto 18m
up to 27m
0.8m -i
1.0m
1.4m
1.0m
1.4m
1.7m
1.4m
1.7m
2.3m
Worked example:
The example below is for a G1l2 temperature relief valve with a discharge pipe (D2) having 4 no.elbows
and length of 7m from the tundish to the point ofdischarge.
From Table 1 : Maximum resistance allowed for a straight length of 22mm copper discharge pipe (D2) from
a Gll2 temperature relief valve is 9.0m. Subtract the resistance fo r 4 no.22mtm elbows at 0.8m each =
3.2m
Therefore the maximum permitted length elbows equates to 5.8m is less than the actual length of 7m
therefore calculate the next largest size. Maximum resistance allowed for a straight length of zgmm pipe
(D2) from a G112 temperature relief valve equates to l8m.Subtract the resistanie for 4 no.2gmm elbows
at 1.0m each = 4m.
Therefore the maximum permitted length equates to l4m.
As the actual length is 7m, a 28mm (D2) copper pipe will be satisfactory.
The tundish should be vertical, located in the same space as the Spa tank and fitted as close as possible
and within 500mm of the temperature relief valre.
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 1 8m equivalent resistance length should be at least two sizes larger than the
nominal outlet size of the safety device, between 18m and 27m at least 3 sizes larger, and so
on' Bends must be taken into account in calculating the flow resistance. Refer to the worked
example.
An alternative approach for sizing discharge pipes would be to follow 856700: 1987
Specification for design, installation, testing and maintenance of services supplying water for
I domestic use within buildings and their curtilages, Appendix E, section E2 and table 2l .

c)
d)
i)
ii)
i ii)
iv)
b) have a vertical section of pipe at least 300mm long, below the tundish before any elbows or
bends in the pipework
be installed with a continuous fall.
have discharges visible at both the tundish and the final point of discharge but where this is
not possible or is practically difficult there should be clear visibility at one or other of these
locations. Examples of acceptable discharge arrangements are;
ideally below a fixed grating and above the water seal in a trapped gully.
Downward discharges at low level; i.e. up to 1OOmm above external surfaces such as car
parks, hard standings, grassed area etc. are acceptable providing that where children may play
or otherwise come into contact with discharges a wire cage or similar guard is positioned to
prevent contact, whilst maintaining visibility.
Discharges at high level; e.g. into a metal hopper and metal down pipe with the end of the
discharge clearly visible (tundish visible or not) or onto a roof capable of withstanding high
temperature discharges of water 3m from any plastics guttering system that would collect
such discharges (tundish visible)
Where a single pipe serves a number of discharges. such as in block of flats, the number
served should be limited to not more than 6 systems so that and installation discharging can
be traced reasonable easily.The single common discharge pipe should be at least on pipe size
larger than the largest individual discharge pipe D2 to be connected lf unvented hot water
storage systems are installed where discharges from safety devices may not be apparent i.e.
in dwellings occupied by blind, infirm or disabled people,consideration should be given to
the installation of an electronically operated device to warn when discharge takes place.
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Note: The discharge will consist of scalding water and steam. Asphalt, roofing felt and nonmetallic rainwater goods may
be damaged by such discharges.
7. Flushing and Commissioning
- Ensure all pipe connections are tight, including immersion heate(s).
- Check the immersion heater setting is not above 60C and that the live and neutral connec-
tions are correct.
- Open a hot tap farthest from the unit. Open the mains stop cock to fill the unit.
- Flush for three minutes.
- Close off taps and check pipework for leaks.
- Switch on electricity to the immersion heate(s) or switch on the boiler. Refer to boiler manu
facturer s instructions or commissioning.
- Bring the unit to approx 65C. Check that water does not discharge via theTundish pipework
during heating.

Cut out
lmmersion
HeaterWring
Connect Live to
thermostat
Heat resisting cable
from Double Pole
isolating switch
Connect Earth
Connect Neutral
- Hand guarantee card to user.
8. Electrical Specification & Wiring (lmmersion Heater)
- Element terminals are marked N(Neutral) and L(Live)
- Ensure earth connection of 3 wire supply is connected to earth.
- Recommended supply for 3kW element is 2.5mm cable to 85614l
- A 16 Amp timer is recommended for 3kW elements
-The unit is not fitted with a fuse.
- All heating elements operate on a 230 VAC 50Hz mains supply. Do not fit immersion
heate(s) without thermal cutout(s).
FUSE RATING:
The fuse rating for two 3kW immersion heaters wired separately from the main fuseboard should be l5
Amps.
Electrical Wiring
Drawing
Cylinder Thermostat
From Timeclock Motorised Valve
DHW Output
N
E
L
To Boiler
Electrical Specification and Wiring (Thermostat Control)
- The cylinder control thermostat is mounted at the top of the unit in a housing with cable
entry point.
- The unit houses two thermostats, a control thermostat and an overheat thermostat.
Operation of either thermostat must cease the supply of heat to the cylinder.
- Remove the thermostat housing cover. Wire the two thermostats inside in series to the hot
water control valve as shown below. Electrical 5pecification and Wiring (Thermostat Control)
for additional heat source refer to the suppliers manual. However, the manual reset limit ther
mostat should be used to isolate any further supply of heat to the Spa.
9. Secondary Circulation
- A pump is required together with a non-return valve.
- The pump should be fitted with isolating valves on either side and sited to minimise air
accumulation away from the high point of the circuit. An air bleed valve may be located at
1O the high point.

- The return pipe shourd be fitted to the secondary return/drain off tapping near the base of
the cylinder.
- A drain off cock (not suppried) shourd be fitted iniine in the secondary return near the
connection to the cylinder to,faciritate dninage.of the cyrinder for main,"nun.. priiir"r.
- A non-return valve (not supplied) must be fittea to prevent backflow.
- calculate the flow rate and pump size by determining the totar heat ross in flow and return
in wafts.
- consid,eration should be given to the fitting of an additional vessel where excessively large
secondary loop circuits are used.
Required flow rate
3.Water is cold
- Crossflow from cold supply
- Boiler not switched on
(indirect)
- Air locked primary flow
- Thermostat settings incorect
- Cut out switch need reset
= Totalwatts litres/second
4186x t000xT
whereT = temperature difference between flow and return (normally the desirable drop is 5C and the
hot water temperature should be 60C).
'10. Scale Advice and Maintenance
- ln areas of hard water high storage temperatures (above 50C) will result in scale deposition
- lt is advisable to set-the thermostat to the required level and fit a water softener or scale
inhibitor (capabre of the required circuit flowrate) in the cord suppry rine.
Maintenance
- The valve easing gear on the pressure and temperature relief valve must be operated at
least once every 6 months.
- The charge pressure of the expansion vessel should be checked annually with a pressure
gauge at the top (and whh a hot tap open and the cold supply turned o?f). Recharge with
clean dry air to 3.5 bar.
- clean the pressure reducing valve filter every 2 years or of flow from water heater begins to
deteriorate.
l l.Trouble Shooting & Fault Guide i
WARNINGS
lf hot water discharges at tundish do not turn off supply main, switch off power to electric
elements and shut down heating boiler (indirect modeis)
The cause of this could be a failure of the safety controls and you should immediately contact
your installer or our service operator.
SYMPTOM5 POSSIBLE CAUSES
1. No or low flow - poor mains pressure
- Restricted pipework
- Mains stopcock
- Sticking jumper in stop
- Blocked filter
2. Discharging cold - Loss of expansion vessel
- Defective pressure
- Blocked or defective
ACTION
- Check that all arrows on valves are in water flow direction.
- Use larger diameter pipework
- Operate stopcock or replace
- Replace stop cock
- Clean filter
- Check and recharge vessel reliefvahe (with hot tap open)
- Replace pressure valve reducing valve
- Operate expansion valve expansion reliefvalw
mechanism to clear or replace
- Check mixer taps and fit check through mixer top or other
\lalve on hot outlet from heater fittlngs.
- CARRY OUT PROCEDURE BELOW
Warnings (Electric Modelt
Always isolate the electrical supply before opening heating elements.
Confirm that power supply is reaching the elemenls.
lfthermal cut-out switches have operated press in the red button. rf this fairs to heat the
cylinder the element has failed and should be replaced. Fit new element and reset thermal cut-out.
wth power to the element and the cut-out reset, check the vottage on thermar cut-out outpui.
lf this is incorrect replace cut-out switch. - 1 1

1 2. Spares
ITEM DESCRIPTION
1/2 inch Temperature and
Pressure ReliefValve
3/4inch pressure reduction valvg
expansion relief manifold
1 2 litre Expansion Vessel
(1 20, 1 50 litre sizes)
1 8 litre Expansion Vessel
(210 litre size)
24 litre Expansion Vessel
(300 litre size) '
lmmersion Heater
Control Thermostat
ovdrheat Thermostat
Motorized Valve 22mm
Tundish
Diagnostic Gauge
Expansion Vessel Hose
MODEL
K51.120.04.00.1
K5r.12s.06.00.0 2
K5t.200.01.00.1
KSt.300.03.00.0
K51.400.01.00.1
KSt.125.02.00.1
KS1.12s.03.02.0
K51.125.03.01.0
KSt.125.07.00.2
Kst.l 25.10.00.0
SPECIFICATION
1/2 inch male inlet, 15mm comp.
outlet,90C,7 bar
2mm comp inlet,22mm comp
outlet,3 bar supply,6 bar relief.
3/4 inch male inlet.3 bar
3/4 inch male inlet.3 bar
3/4 inch male inlet.3 bar
3kW. 2.25 inch male.80C cut-out
1.75inch boss
Adjustable 30 to 70C
80C Cut-Out Manual Reset
22mm 2-port VElve
15mm/22mm Compression
13. Safety & Relevant British Standards
lnstallation of this tank as an unvented hot water system falls within the scope of the Building
Regulations I 995 (Part G).These require that installation of an unvented sysiem shall be noti
fied to the local authority Building control Department;also that the work mrst be carried
out by a competent person as defined in the Approved Document G3.
The Electricity ar Work Regulations 1989.
The manufacturers notes must Nor be taken, in any way, as overriding statutory obligations.
Tank Data Plate
Single Coil Spa Twin Coil Soa
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Twin Coil Spa
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