Kohler Mira Zest User manual

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These instructions are to be left with the user
Installation and User Guide
ELECTRIC SHOWER
MIRA ZEST

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CONTENTS
Introduction ............................................................................................. 3
Important Safety Information ................................................................. 4
Pack Contents ......................................................................................... 6
Specifications .......................................................................................... 7
Dimensions .......................................................................................... 7
Wiring Diagram .................................................................................... 7
Plumbing .............................................................................................. 8
Electrical .............................................................................................. 8
Standards and Approvals ..................................................................... 8
Flow Rate Graph .................................................................................. 8
Installation Requirements ...................................................................... 9
Plumbing .............................................................................................. 9
Electrical ............................................................................................ 11
Installation ............................................................................................. 12
Commissioning ..................................................................................... 14
Operation ............................................................................................... 16
Fault Diagnosis ..................................................................................... 18
Maintenance .......................................................................................... 22
Cleaning ............................................................................................. 22
Cleaning the Inlet Filter ...................................................................... 22
Relief Valve Assembly - Resetting .................................................... 23
Spare Parts ............................................................................................ 24
Spare Parts List ................................................................................. 24
Spare Parts Diagram .......................................................................... 25
Notes ...................................................................................................... 26
Customer Service .................................................................... Back Page

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INTRODUCTION
Recommended Usage
Domestic
Light Commercial
Heavy Commercial
Healthcare
X
X
W
W
If you experience any difficulty with the installation or operation of your new shower
control, then please refer to "Fault Diagnosis", before contacting Kohler Mira Limited.
Our telephone and fax numbers can be found on the back cover of this guide.
Thank you for purchasing a quality Mira Zest Electric Shower. To enjoy the full potential
of your new shower, please take time to read this guide thoroughly, and keep it handy
for future reference.
Mira Zest electric showers have separate controls for power selection and for
temperature/flow adjustment. A unique flow regulator stabilises any temperature
changes caused by water pressure fluctuations, which can result from taps being
turned on or off or toilets being flushed.
Products covered by this guide:
Mira Zest 7.5 A 7.5 kW 240 V AC (6.9 kW 230 V AC) heater. Available in a
white finish.
Mira Zest 8.5 A 8.5 kW 240 V AC (7.8 kW 230 V AC) heater. Available in a
white finish.

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Warning!
1. Products manufactured by us are safe and risk-free, provided that they are
installed, used and maintained in good working order, in accordance with our
instructions and recommendations.
2. THIS APPLIANCE MUST BE EARTHED.
3. In accordance with ‘The Plugs and Sockets etc. (Safety) Regulations’ in force at
the time of installation, this appliance is intended to be permanently connected
to the fixed electrical wiring of the mains system.
4. DO NOT twist the individual cable cores of the live and neutral conductors, as
this will prevent them from entering the terminal block.
5. Make sure that any pipework that could become frozen is properly insulated.
6. DO NOT operate this appliance if it is frozen. Allow the appliance to thaw before
using. The shower unit must not be fitted where it may be exposed to freezing
conditions.
7. DO NOT fit any form of outlet flow control as the outlet acts as a vent for the tank
body. Only Mira Showers recommended outlet fittings should be used.
8. If water leaks from the pressure relief valve, maintenance will be required before
the appliance can be safely used.
9. There are no user-serviceable components beneath the cover of the appliance.
Only a competent tradesperson should remove the cover.
10. If any of the following conditions occur, isolate the electricity and water supplies
and refer to To contact us, on the back page of this guide.
• The cover is not correctly fitted and water has entered the appliance
case.
• The case is damaged.
• The appliance begins to make an odd noise, smell or smoke.
• The appliance shows signs of a distinct change in performance, indicating
a need for maintenance.
• The appliance is frozen.
11. Isolate the electrical and water supply before removing the cover.
12. Mains connections are exposed when the cover is removed.
13. Refer to the wiring diagram before making any electrical connections.
14. Make sure all electrical connections are tight, to prevent overheating.
15. This product is not suitable for areas with very high humidity (i.e steam rooms).
Please consult your installer.
IMPORTANT SAFETY INFORMATION

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Caution!
1. Read all of these instructions and retain this guide for later use.
2. Pass on this guide in the event of change of ownership of the installation site.
3. Follow all warnings, cautions and instructions contained in this guide, and on or
inside the appliance.
4. The electrical installation must comply with the “Requirements for Electrical
Installations” (commonly referred to as the IEE Wiring Regulations), or any
particular regulations and practices, specified by the local electricity supply
company in force at the time of installation. The installation should be carried out
by an electrician or contractor who is registered, or is a member of, an association
such as:
• National Inspection Council for Electrical Installation and Contracting
(NICEIC), throughout the UK.
• The Electrical Contractors Association (ECA), England and Wales.
• The Electrical Contractors Association of Scotland (ECAS).
5. This is a high power unit; it is essential to contact your electricity supply company
to ensure that the electricity supply is adequate for the purpose.
6. The plumbing installation must comply with the requirements of UK Water
Regulations/Bye-laws (Scotland), Building Regulations or any particular regulations
and practices, specified by the local water company or water undertakers. The
installation should be carried out by a plumber or contractor who is registered, or
is a member of, an association such as:
• Institute of Plumbing (IOP), throughout the UK.
• National Association of Plumbing, Heating and Mechanical Services
Contractors (NAPH & MSC), England and Wales.
• Scottish and Northern Ireland Plumbing Employers’ Federation (SNIPEF),
Scotland and Northern Ireland.
7. This appliance is not thermostatic and can produce scalding temperatures if not
operated in accordance with the instructions given in this manual.
8. Anyone who may have difficulty understanding or operating the controls of any
shower should be attended whilst showering. Particular consideration should be
given to:
• the young
• the elderly
• the infirm
• the disabled
• anyone who suffers from a medical condition that can result in temporary
incapacity (e.g. epilepsy or blackouts).
• anyone inexperienced in the correct operation of the controls.
9. When this appliance has reached the end of its serviceable life, it should be
disposed of in a safe manner, in accordance with current local authority recycling,
or waste disposal policy.

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PACK CONTENTS
¸3 x Wall Plugs
¸3 x Fixing Screws
¸1 x Mira Zest Electric Shower
Documentation
¸1 x Installation & User Guide
¸1 x Installation Template
¸1 x Guarantee Brochure
ZTick the appropriate boxes to familiarise yourself with the part names and to
confirm that the parts are included.

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SPECIFICATIONS
205 mm 103 mm
53 mm
310 mm
Dimensions
Wiring Diagram

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Plumbing
1. Minimum maintained inlet pressure for satisfactory operation: 0.7 bar (70 kPa)
2. Maximum static inlet pressure: 10 bar (1000 kPa)
3. Minimum static pressure to keep the flow valve closed: 0.5 bar (50 kPa)
Electrical
1. The appliance requires a 40 Amp fuse.
2. The terminal block will not accept cable larger than 10 mm2.
Standards and Approvals
1. This Mira Zest shower complies with all the relevant directives for CE marking.
Flow Rate Graph
1. These curves are for the specified outputs at 240 V.
2. All appliance heating elements have a manufacturing tolerance. Flow rates may
be above or below those shown on the flow rate graph.
3. The left-hand axis shows temperature rise.
Temperature rise = (Showering temperature) - (Supply water temperature)
Example: For the Mira Zest 8.5 kW on full power setting with an incoming water
supply at 10°C and a showering temperature at 42°C, the temperature rise is 32°C.
The flow rate is therefore, 4 l/min.
Flow Rate (l/min)
Temperature Rise (°C)
7.5 kW
8.5 kW

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Plumbing
1. The Mira Zest 7.5 kW and 8.5 kW electric showers are designed to operate with
a minimum maintained inlet pressure of 0.7 bar (70 kPa) up to a maximum
static inlet pressure of 10 bar (1000 kPa).
2. The appliance is normally connected to the cold water mains-fed supply. However,
the water supply can be taken from a cold water storage cistern, provided there
is a minimum maintained inlet head of water of 7 metres (the vertical distance
from the base of the cold water storage cistern to the shower fitting handset). To
reduce pressure losses and fluctuations, the cistern-fed water supply must be
independent from other supply draw-offs, and should avoid long horizontal pipe
runs and use swept bends rather than 90° elbows. For further advice please
refer to the back cover of this guide for Mira Showers contact telephone and fax
numbers.
3. The appliance is suitable for installation within the shower area. It is fitted with a
pressure relief device and must be positioned over a water catchment area with
the controls at a convenient height for the user. The shower fitting should be
positioned so that it discharges down the centre line of the bath, or across the
opening of a shower cubicle, and must be directed away from the appliance.
4. The appliance is fitted with an inlet connector assembly that is designed to accept
plumbing supplies from the top or bottom. The water supply can be fed with
15 mm pipe or 10 mm microbore pipe, suitably adapted into the inlet connector
assembly. If 10 mm microbore is used, then an allowance for increased pressure
loss must be made to ensure that the minimum maintained inlet pressure is
achieved.
5. Do not fit the appliance to the wall and tile up to the case. The appliance must be
fitted onto a finished flat and even wall surface. Otherwise, difficulty may be
encountered when fitting the cover, and subsequent operation of the unit could
be impaired (small pillars moulded on to the back of the case allow air circulation).
6. Use only the inlet connector assembly supplied with the appliance. Do not use
any other types of fitting.
7. Refrain from applying excessive force when making any connections. Always
provide mechanical support when making the plumbing connections.
8. This appliance is not designed to be plumbed directly from the rear. For a rear-
entry supply, add an elbow to the supply pipe and connect it as a rising or falling
supply.
9. Do not install the appliance in a position where it may become frozen. The
shower unit must not be fitted where it may be exposed to freezing conditions.
The shower unit must not be used if you suspect it may be frozen.
INSTALLATION REQUIREMENTS