Mira Gem 88 Operation manual

Installation & User Guide
MIRA GEM 88
These instructions are to be left with the user
SHOWER CONTROL

2
CONTENTS
Introduction.............................................................................................3
Important Safety Information .................................................................4
PackContents Checklist .........................................................................5
Dimensions .............................................................................................7
Specifications..........................................................................................8
1. PressureRange ..............................................................................8
2.Connections.....................................................................................8
3.StoredWater Temperature ...............................................................8
4. Flow Rates.......................................................................................9
InstallationRequirements .................................................................... 10
Typical suitable installations ..............................................................11
Installation............................................................................................. 16
Mira Gem 88 - Surface Mounted Shower Control................................ 16
1. Rising and falling inlet supplies ......................................................16
2. Rear entry inlet supplies.................................................................19
Mira Gem 88 B - Built-in Shower Control ............................................ 22
1. Solid or dry-lined wall structures ....................................................22
2. Stud partition or dry partition wall structures...................................26
3.Showercubicleorlaminatedpanel .................................................28
Refitting the Cavity Seal ....................................................................... 30
ReversedInlets...................................................................................... 32
Operation............................................................................................... 33
Maintenance .......................................................................................... 34
Faultdiagnosis ..................................................................................34
General ..............................................................................................35
Spare Parts ............................................................................................ 36
Accessories ........................................................................................... 40
Notes...................................................................................................... 41
CustomerService.................................................................... Back Page

3
Ifyouexperienceany difficulty with theinstallationoroperationofyour new shower
control,thenpleasereferto"FaultDiagnosis",beforecontactingKohlerMiraLimited.
Our telephone and fax numbers can be found on the back cover of this guide.
INTRODUCTION
Thank you for purchasing a quality Mira product. To enjoy the full potential of your
new product, please take time to read this guide thoroughly, having done so, keep it
handyforfuturereference.
ArangeofMira1/2"manualshowercontrolswhichprovideindependentselectionof
spray force and temperature. The Mira Gem 88 is available with a choice of surface
mountedandbuilt-inmodels.
The Mira Gem 88 is not a thermostatic shower control and does not sense supply
temperatureorpressurevariations. Therefore,inletwatertemperaturesandpressures
especiallythehot,should berelativelyconstantinordertomaintainastable showering
temperature.
The Mira Gem 88 is suitable for installation with the following packages:-
- Gravity fed systems (balanced pressure hot and cold)
- Pumpedsystems(balancedpressurehotandcold)
- Unventedthermalstore*(balancedpressure hot and cold)
- Unventedsystems * (balanced pressure hotand cold)
* Fitted with a pressure reducing valve (PRV) recommended to be set at 3.5 bar.
The Mira Gem 88 is not suitable for mains pressure (cold) with gravity pressure
(hot) or combination boilers/instantaneous water heaters.
Shower controls covered by this guide:
Mira Gem 88
Surfacemountedshowercontrolforconnectiontoexposed pipework.
Chromeorwhitecolourmodels are available.
The Mira Gem 88 is designed to be fitted with the pipe centres set at a distance of
153 mm for rear supply connection and the pipes centre set at a distance of 151 mm
for rising / falling pipes connection (See the installation template provided).
Ifthe MiraGemis replacinganexistingshower,thedistancebetweenthe pipecentres
can vary from 149 to 154 mm to facilitate the installation.
Mira Gem 88 B
Built-inshowercontrolforconnectiontoconcealed pipework.
Chromeorwhitecolourmodels are available.

4
IMPORTANT SAFETY INFORMATION
Warning!
1. Productsmanufacturedbyusaresafeandwithoutriskprovidedtheyareinstalled,
used and maintained in good working order in accordance with our instructions
andrecommendations.
Caution!
1. Read all of these instructions.
2. Retain this guide for later use.
3. Pass on this guide in the event of change of ownership of the installation site.
4. Follow all warnings, cautions and instructions contained in this guide.
5. Anyone who may have difficulty understanding or operating the controls of any
showershouldbeattended whilst showering. Particularconsiderationshouldbe
giventotheyoung, the elderly,theinfirm,oranyoneinexperienced in thecorrect
operationofthecontrols.
6. The temperature control can be turned from FULL HOT to FULL COLD. As
such, turning the control to full hot will deliver water at the hot water storage
temperature.
7. Whenthisproducthasreachedtheendofitsserviceablelife,itshouldbedisposed
ofina safemanner,inaccordance withcurrentlocalauthority recycling,orwaste
disposal policy.

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2 x Pipe Concealing Plates 
**2 x Olives 
** 4 x Concealing Caps
(2 Spares)
1 x Mira Gem 88 Shower Control 
** 2 x Wall Plug ** 1 x 2.5 mm A/F
Hexagonal Wrench 
** Supplied in the component pack.
1 x Installation Template 
2 x Compression Nuts 
** 1 x Flow Regulator 
Tick the appropriate boxes to familiarize yourself with the part names and to
confirm that the parts are included.
1. Mira Gem 88 Surface Mounted Shower Control
PACK CONTENTS CHECKLIST
9

** 2 x Fixing Screws 

6
2. Mira Gem 88 Built-in shower control
3.Documentation
1 x Installation & User Guide 
1xCustomerSupportBrochure 
1 x Mira Gem 88 B Shower Control
With Building-in Shroud ** 2 x Fixing Screw 
** 2 x Wall Plug ** 1 x 2.5 mm A/F
Hexagonal Wrench 
1 x Concealing Plate 
1 x Concealing Plate
Bracket Assembly 
** 2 x Flow regulator 
1 x Temperature Knob 
1 x Grey Indicator
Trim Bearing 
1 x Indicator Trim 
1 x Flow Lever 
1 x Flow Control Bearing 
** Supplied in the component pack.

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190
126
Note! NOT TO SCALE - All dimensions are nominal and in millimetres
35
149 - 154
172
35 91
50 - 68
DIMENSIONS
2. Mira Gem 88 Built-in shower control
1. Mira Gem 88 Surface Mounted Shower Control

8
1. Pressure Range
Mira Gem 88
1.1 Minimum maintained pressure 0.1 bar (1.0 metre head) when used with Mira
showerfittings.
1.2 Maximummaintainedpressure5bar.
1.3 Maximum static pressure 10 bar.
Mira Gem 88 B
1.4 Minimummaintainedpressure0.1 bar.
1.5 Maximummaintainedpressure5bar.
1.6 Maximum static pressure 10 bar.
2.Connections
Mira Gem 88
2.1 Inlet 15 mm compression.
2.2 Outlet 1/2" BSP male/15 mm Compression.
Mira Gem 88 B
2.3 Inlet 1/2" BSP female.
2.4 Outlet 1/2" BSP female.
3. Stored Water Temperature
3.1 It is recommended that the temperature of stored water should never exceed
65°C. A stored water temperature of 60°C is considered sufficient to meet all
normalrequirementsandwillminimisethedepositionofscaleinhardwaterareas.
SPECIFICATIONS

9
4. Flow Rates
0
5
10
15
20
25
30
35
050100 150 200 250 300
Supply Pressure kPa
Flow Rate l/min
0
5
10
15
20
25
30
35
0 50 100 150 200 250 300
Supply Pressure kPa
Flow Rate l/min
Force
Sooth
Start
Economy
Sooth
Economy
Start
Force
Mira Gem 88 with HC Response Shower Fittings
Mira Gem 88 with LC Response Shower Fittings

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Readthesection 'Important Safety Information' first.
Installation must be carried out in accordance with these instructions, and must be
conductedbydesignated,qualifiedand competent personnel.
1. Installations mustcomply with UKWaterRegulations/Bye-laws(Scotland), and
Building and Plumbing Regulations in force at the time of installation.
2. Layout andsizing of pipework must besuchthatwhenotherservicesare used,
pressures at the shower control inlets are maintained approximately equal and
do not fallbelowtherecommendedminimum.
3. Do not install the product in a position in which service access is restricted.
4. Do not fit any form of flow control in the shower outlet.
5. Do not use excessive force when making connections.
6. Do not install the product in a position where it could become frozen.
7. Do not installthe Gem88toan instantaneouswaterheater orcombinationboiler
system.
8. The Mira Gem 88 is designed to be fitted with the pipe centres set at a distance
of 153 mm for rear supply connection and the pipe centres set at a distance of
151mm forrising/fallingpipesconnection(Seetheinstallationtemplateprovided).
If the Mira Gem 88 is replacing an existing shower, the distance between the
pipes centre can vary from 149 to 154 mm to facilitate the installation.
INSTALLATION REQUIREMENTS

11
1. Gravity fed showers - The shower control MUST be fed from a cold water
storage cistern andhot water cylinder providingnominallyequal pressures.
Typical suitable installations
Key to symbols
Drop tight pressure reducing
valve (PRV)
Twin impeller inlet pump
Float operated valve
Stop or servicing valve
Shower control
Warning or overflow pipe Non-return Valve
Mini expansion vessel
Tempering valve
Gravity Fed Showers

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2. Pumped showers (inlet pumps) - The shower control can be installed with an
inletpump(twinimpeller).Thepump MUST belocatedonthefloor nexttothe hot
watercylinder.Thehot water cylinder/vent pipes must be arranged as shown to
achieveairseparation.
Pumped Showers (inlet pumps)
Pumped Showers (outlet pumps)
3. Pumped showers (outlet pumps) -Theshowercontrol can beinstalledwithan
outletpump(singleimpeller).Thepump MUST belocatedon thefloorneartothe
showercontrol. Thehotwatercylinder/ventpipemustbearrangedasshownto
achieveairseparation.
90 °
30 ° to 60 °
30 ° to 60 °
90 °

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HOT
COLD
Combined outlet PRV
with internal non-return valves
- Expansion vessel required.
Cold takeoff after PRV
- Expansion pressure taken up by
unvented cylinder expansion vessel.
Reduced pressure to cold inlet of shower
Reduced pressure
to unvented cylinder
High Inlet Pressure
Reduced pressure to
cold inlet of shower
Expansion Vessel
Safety devices
not shown
for clarity
4. Unvented mains pressure showers - The shower can be installed with an
unvented, stored hot water cylinder. Only a "competent person" as defined by
the Building Regulations may fit this type of system.
Forpackageswith nocoldwatertake off aftertheappliancereducing valve,itwill
be necessary to fit an additional drop tight pressure reducing valve when the
mainspressureisover 5bar.Thedroptight pressure reducingvalvemustbeset
at the same value as the unvented package pressure reducing valve.
Note!An expansionvesselMUST befitted(and regularlymaintained)if anyform
ofbackflowpreventiondeviceis fitted, e.g. non-return valveorcheckvalve.This
willensurethat excess expansionorpulsepressures donotdamagetheproduct
or the plumbing system.
High Inlet Pressure
Reduced pressure
to unvented cylinder
Unvented Mains Pressure Showers

14
5. Mains pressurised instantaneous hot water shower, heated from a thermal
store - Packages of this type, fitted with a tempering valve can be used. A drop
tight pressure reducing valve MUST be fitted if the supply pressures exceed 5
barmaintained.
An expansion vessel MUST be fitted (and regularly maintained) if any form of
backflow prevention device is fitted, e.g. non-return valve or check valve. This
will make sure that excess expansion or pulse pressures do not damage the
product or the plumbing system. The expansion vessel may already be fitted
externally or internally within the thermal store (check with thermal store
manufacturer).
COLD HOT
NOT SUITABLE FOR
HOTCOLD
INSTANTANEOUSWATER
HEATERS/COMBINATIONBOILERS GRAVITY HOT - MAINS PRESSURE
COLD

15
High pressure installations
Ifwaterflowfrom the shower istoohighormaintainedpressure over 1 bar,thefitting
ofaflowregulatorisrecommended(asillustratedbelow).
Exposed shower valves and BIV
Fit the white 12 l/min flow regulator to the
hose.
BIRProducts
Fit the brown 12 l/min flow regulator.
Nipple Outlet
Washer
Flow Regulator
Hose
Flow Regulator
Flow Regulator
Flow Regulator

16
Backplate
Grub
Screw
Mira Gem 88 - Surface Mounted Shower Control
1. Rising and falling inlet supplies
1.1 Determinewhetherthehotorcoldwater
services will be connected to the
showercontrolfromthebottom(rising)
ortop(falling).
1.2 TheMiraGem 88issupplied withinlet
connections hot left, cold right and
bottom outlet as standard.
1.3 Decide on a suitable position for the
shower control. The position of the
showercontroland theshowerfittings
must provide a minimum gap of 25
mmbetweenthe spill-over levelofthe
showertray/bathandthehandset.This
istopreventback-siphonage.
1.4 Use the installation template to mark
the positions of the holes for the
backplate.
Note! For rising/falling supplies the
distance between the pipe centres is
151mm(Seetheinstallationtemplate)
1.5 Loosenthebackplategrubscrewsand
using the 2.5 mm A/F hexagonal
wrench provided, remove the
backplate from the shower control
body.
Hose Retaining Ring
25 mm Minimum
Spill-over
Level
Spirit Level
Installation Template
151 mm
INSTALLATION

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1.6 Drill and suitably plug the two fixing
holes. Securethebackplatetothewall
by means of the screws provided.
1.7 Install the hot and cold supply pipes.
Thedistancebetweenthepipe centres
must be 151 mm.
1.8 Adjusttheinletelbowtoaccept falling
or rising supplies as follows:-
Using the 2.5 mm A/F hexagonal
wrench loosen the grub screws and
removetheinlet elbows.
Make sure that the 'O' seal is on the
inlet connector, not in the 'V' groove.
Turn the inlet elbows to the required
position and refit onto the inlet
connectors.
Tightenthegrubscrews to fixtheinlet
elbows and fit the concealing caps.
1.9 Locate the shower control body onto
thebackplateandsecurebytightening
therecessedgrubscrewusingthe 2.5
mmA/Fhexagonalwrench.
Backplate
WallPlug
Screw
Inlet Elbow
'O' Seal
Shower Control Body
Grub Screw
Concealing Cap
V Groove

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1.10Thoroughly flush the incoming hot
and cold water supply pipes before
connecting the shower control.
1.11Fit the compression nuts and olives
over the supply pipes and then make
the connection to the inlet pipework.
Make sure that you protect the plated
surfaces.
1.12Turn on the water supplies to the
showermixer andcheckforanyleaks.
1.13Turn the flow lever 1/4 of a full turn
anticlockwiseforwaterflow. Operate
temperatureknobandmake sure that
thedirectionalhotandcold indicators
arecorrect.
HOT = anticlockwise
COLD = clockwise
Note! If this is not the case, refer to
section: Reversed inlets.
Turn flow lever fully clockwise to stop
waterflow.
1.14This completes the installation of the
Mira Gem 88 for connection torising
and falling inlet supplies.
Compression Nut
Olive Nipple
Flow lever
Temperature Knob

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2.0 TheMiraGem 88issuppliedwithinlet
connections hot left, cold right and
bottom outlet asstandard.
2.1 Decide on a suitable position for the
shower control. The position of the
showercontroland theshowerfittings
must provide a minimum gap of 25
mmbetweenthe spill-over levelofthe
showertray/bathandthehandset.This
istopreventback-siphonage.
2.2 Use the installation template to mark
the positions of the holes for the
backplate and the pipes centre.
2.3 Use a spirit level and a pencil to mark
the route for the hot and cold water
supply pipes at 153 mm centres.
Note! If the Mira Gem is replacing an
existingshower,thedistancebetween
thepipecentresisadjustablefrom149
to 154 mm to facilitate installation.
2.4 Removetheplaster and brick/blockto
the required depth to conceal the
pipework.
2.5 Install the supply pipes. The pipes
must project from the finished wall by
13 mm. Finish the surface of the wall
as required. The recesses in the wall
for the concealing plates must be 32
mm diameter x 10 mm deep.
13 mm From Finished
Wall Surface
WallPlug
Spirit Level
153 mm Centres
Backplate
Screw
InstallationTemplate
Hose Retaining Ring
25mmMinimum
Spill-over
Level
153 mm
2. Rear entry inlet supplies

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2.6 Loosenthebackplategrubscrew and
using the 2.5 mm A/F hexagonal
wrench provided, remove the
backplate from the shower control
body.
2.7 Drill and suitably plug the two fixing
holes. Securethebackplatetothewall
by means of the screws provided.
2.8 Fit the concealing plates over the
pipework into the enlarged recess in
the finished wall surface.
2.9 Thoroughly flush the incoming hot
and cold water supply pipes before
connecting the shower control.
2.10Fit the compression nuts and olives
to the supply pipes.
2.11Alignthevalveover thebackplateand
inlet pipe work. If the pipe work and
thenipplesarenotaligned,thenipples
can be moved to achieve the
alignment. This adjustment can
achieve an alignment of the pipes
centrebetween149-154mm.
2.12Locate the shower control body onto
thebackplateandsecurebytightening
the grub screw using the 2.5 mm A/F
hexagonalwrench (supplied).
Make the connections to the inlet
pipework. Protect the chrome plated
surfaces when tightening the
compressionnuts.
Concealing Plate Supply Pipe
Compression Nut
Olive