ELECTRIC SHOWER
Installation & User Guide
THESE INSTRUCTIONS ARE TO BE LEFT WITH THE USER
1
Contents
Introduction.......................................................................................................... 3
Important Safety Information .............................................................................4
Pack Contents Checklist......................................................................................7
Specifications ......................................................................................................8
Dimensions ....................................................................................................... 8
Wiring Diagram .................................................................................................. 9
Installation Requirements................................................................................. 11
Installation ......................................................................................................... 16
Commissioning ..................................................................................................21
Operation ...........................................................................................................22
Fault Diagnosis ..................................................................................................25
Customer Fault Diagnosis ............................................................................... 25
Installer Fault Diagnosis .................................................................................. 27
Maintenance ...................................................................................................... 30
Cleaning the Inlet Filter ................................................................................... 30
Relief Valve Assembly and Resetting .............................................................. 32
Flow Regulator Assembly/Switch Assembly Removal & Installation ............... 33
Heater Tank-Removal and Installation ............................................................. 36
Thermal Trip-Removal and Installation ............................................................. 39
Spare Parts ........................................................................................................ 40
Guarantee, Customer Care policy , and How to contact us ............................ 4 4
2
Introduction
Thank you for purchasing a quality Mira Zest 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 – An 7.5 kW 240 V AC (6.9 kW 230 V AC) heater. Available in a white
finish.
Mira Zest 8.5 – An 8.5 kW 240 V AC (7.8 kW 230 V AC) heater. Available in a white
finish.
Recommended Usage
Domestic
Light Commercial
Heavy Commercial
Healthcare
If you experience any difficulty with the installation or operation of your new
shower control, please refer to the Fault Diagnosis section before contacting
Kohler Mira. Our telephone and fax numbers can be found on the back cover
of this guide.
3
Important Safety Information
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. Ensure 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.
4
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.
5
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.
6
Pack Contents Checklist
Tick the appropriate boxes to familiarise yourself with the part names and to
confirm that the parts are included.
3 x Wall Plugs
3 x Fixing Screws
Documentation
1 x Installation & User Guide
1 x Installation Template
1 x Guarantee Brochure
1 x Mira Zest Electric Shower
7
Dimensions
Specifications
205mm 103mm
310mm
53mm
8
Wiring Diagram
9
Plumbing
1. Minimum maintained inlet pressure for satisfactory operation: 0.7 bar
2. Maximum static inlet pressure: 10 bar
3. Minimum static pressure to keep the flow valve closed: 0.5 bar
Electrical
1. The appliance requires a 40 Amp fuse.
2. The terminal block will not accept cable larger than 10 mm
2
.
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.
8.5 kW
7.5 kW
Temperature Rise (°C)
Flow Rate (l/min)
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.
10
Installation Requirements
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 up to a maximum static
inlet pressure of 10 bar.
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.
11
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.
10. We recommend that a non-restrictive (free-flowing) isolating valve is fitted in the
cold water supply pipe to allow the complete maintenance of the appliance. Do
not use a valve with a loose washer plate (jumper) as this can lead to a build up
of static pressure.
11. To avoid damage to the case when soldered fittings are used, pre-solder the
pipework and fittings before connecting them to the inlet stub.
12. Supply pipework MUST be flushed to clear debris before connecting the
appliance.
13. The appliance is fitted with a 1/2" BSP male outlet thread, to accept a Mira Zest
shower hose.
14. When installed in very hard water areas (above 200 ppm temporary hardness)
your installer may advise the installation of a water treatment device, to reduce
the effects of limescale formation. Appliance malfunction due to excessive
limescale formation is not covered by the manufacturer’s guarantee. Your local
water company will be able to advise on the hardness of water in your area.
12
15. A hose retaining ring is supplied to
prevent the handset from dropping
below the spillover level of the bath
or shower, which could lead to
contamination from back-siphonage.
Hose Retaining Ring
Spillover Level
25 mm minimum
The supplied hose retaining ring should meet the majority of user requirements
for shower installations with flexible outlet fittings. However, there will be
occasions when the hose retaining ring will not provide a suitable solution. In
these instances an outlet double checkvalve must be fitted. This will increase
the required supply pressure typically by 0.1 bar.
Double checkvalves, fitted in the inlet supply to the appliance, cause a pressure
build-up, which could exceed the maximum static inlet pressure for the
appliance.
16. Avoid layouts where the shower hose will be sharply kinked. This may reduce
the life of the hose.
13
Electrical
1. In a domestic installation, the rating of the electricity supply company fuse and
the consumer unit must be adequate for the additional demand. This is a highpower appliance, and it is essential to contact your electricity supply company
to ensure that the supply is adequate for the appliance. Voltage drop due to local
heavy demand will reduce the performance of the shower.
2. The appliance must be earthed by connecting the supply-cable earth conductor
to the earth terminal.
Supplementary bonding: Within the bathroom or shower room, all accessible
conductive parts of electrical equipment and extraneous conductive parts that
are likely to introduce earth potential, must be electrically bonded to earth using
a minimum cable size of 4.0 mm2 if the cable is not mechanically protected (2.5
mm2 if mechanically protected).
3. The minimum cable size (cross-sectional area) required is 6 mm
installation conditions. See note 4.
Important! The shower circuit should be separated from other circuits by at least
twice the diameter of the cable or conduit, and it should not be run through
thermally insulating material or in locations where the ambient temperature is
likely to exceed 30 °C. If any of these conditions are unavoidable it is necessary
to determine the cable size which will prevent damage to the cable caused by
overheating.
4. To obtain full advantage of the power provided by this unit, use the shortest
possible cable route from the consumer unit to the shower.
5. A 30 mA residual current device (RCD) should be fitted. This may be part of the
consumer unit or a separate unit.
2
under normal
14
6. A separate, permanently connected supply must be taken from the consumer
unit to the appliance through a double-pole switch, which has a minimum 3 mm
contact separation. The switch can be a ceiling mounted pull-cord type within
the shower room, or a wall mounted switch in an adjacent room.
7. DO NOT twist the individual cable cores of the live and neutral conductors, as
this will prevent them from entering the terminal block.
8. DO NOT exert strain on the terminal block.
9. DO NOT turn-on the electrical supply until the plumbing has been completed.
Plumbing and Electrical Schematic Diagram
15
Installation
WARNING! Isolate the electrical and water supplies before installing the shower.
Decide on a suitable position for the appliance (minimum distance of 200mm
1.
from the ceiling to allow for cover fit and removal). The position of the
appliance and the shower fittings must provide a minimum gap of 25 mm
between the spill-over level of the shower tray/bath and the handset. This is
to prevent backsiphonage
2. Put the installation template on the wall and mark the positions of the top two
fixing holes. Ensure that there are sufficient lengths of supply pipe and electrical
cable to reach the connection points as shown on the template.
3. Remove the installation template and drill the top two fixing holes. Insert the
supplied wall plugs.
CAUTION! Do not drill into cables or pipes in the wall.
4. Thoroughly flush the supply pipe.
5. On the shower, turn both knobs to the full anti-clockwise position.
6. Remove the three screws that hold the cover on the shower and remove the
cover.
7. Remove the service tunnel from the shower.
Screws
Shower
Service Tunnel
Cover
Screw
16
8. Determine the direction of the
incoming water supply: falling
(entering the shower from the top),
or rising (entering the shower from
the bottom).
Do not use an incoming supply
entering the shower directly from
the back. Add an elbow to the supply
pipe and connect it as a rising or
falling supply.
9. Rotate the inlet connector to suit the
direction of the incoming water
supply.
Inlet Connector
10. The case has thinned sections that
can be removed to allow entry of the
supply pipe and electrical cables.
Remove the top thinned section of
the case for a falling supply, or
remove the bottom thinned section
of the service tunnel for a rising
supply.
11. Do not remove any case if the
electrical cables enter from the back.
Thinned
Section
Service Tunnel
Thinned
Section
17
12. Secure the shower to the wall
loosely through the top two fixing
holes, using the supplied screws.
13. Mark the position of the bottom
fixing hole.
14. Remove the shower from the wall.
Drill the bottom fixing hole and insert
the supplied wall plug.
15. Thoroughly flush the mains-fed
cold water supply pipe. The
supply must be clean and free
from debris BEFORE connecting
the appliance.
16. Replace the shower on the wall and
secure through the three fixing holes,
using the supplied screws.
Screws
17. Connect the inlet supply pipe to the
inlet connector using a 1/2” BSP
nipple with compression nuts and
olives (shown) or a push-fit
connector.
Inlet Connector
Compression
Nut
Olive
1/2” BSP Nipple
Olive
Compression
Nut
Inlet Supply Pipe
18
18. Bring the electrical cables into the case.
19. Strip back sufficient of the outer cable insulation to enable routing to terminal
block.
20. Fit an earth sleeve to the earth wire.
21. Loosen the screws in the terminal block and insert the bare wires into the clamps.
L (Live) = Brown wire
T (Earth) = Green sleeved wire
N (Neutral) = Blue wire
Note! Do not twist the cores of the wires or strain the cables to make them reach
the terminal block.
22. Connect the conductors firmly into the terminal block. Make sure that the bare
cores of each conductor are securely trapped within each conductor clamp.
N
L
Terminal Block
Electrical
Cables
Cold Water Supply Pipe/
Inlet Connector
Outlet
Connector
19
23. If necessary, fit an earth bonding clamp to the supply pipe and ensure that the
bonding complies with the relevant regulations in force at the time of installation.
24. Replace the service tunnel.
25. Replace the cover. If the cover does not fit easily, rotate the knobs slightly so
that they fit onto the spindles. Do not force the cover.
26. Tighten the three cover screws.
Screws
Cover
Spindle
Screw
Service Tunnel
20
Commissioning
Commissioning
If you are unsure how electric showers work, please read through the Operation
section before continuing.
1. Make sure that the TOP control knob is in the 'STOP' position and that the
electrical supply has been isolated.
2. Turn the BOTTOM control knob fully anticlockwise to the full cold position.
3. Turn the water supply fully on at the isolating valve, check that water is not
leaking from the bottom of the case.
4. Switch on the electrical supply at the double pole switch.
5. Turn the TOP control knob to the 'LOW' position. Check that water flows freely
from the shower within a few seconds. If not, refer to the Maintenance section.
The water from the handset will be at full force and at a cool temperature.
6. Turn the BOTTOM knob slowly clockwise. As the knob is rotated the flow will be
reduced and the temperature will remain cool - this shows that the flow regulator
assembly is operating correctly. Return the knob anticlockwise to full cold position.
7. Turn the TOP knob to the 'MEDIUM' position. The temperature of the water
should rise slightly. Allow a few seconds for the warm water to reach the handset
- this shows that the 'MEDIUM' power setting is operating correctly.
8. Turn the TOP knob to the 'HIGH' position. The temperature of the water will rise
further - this shows that the full power setting is operating correctly.
9. Set the shower temperature by rotating the BOTTOM knob as necessary. Turn
the knob clockwise for hotter water and anticlockwise for cooler water.
Note! When the temperature is changed the flow rate will change.
10. When the required temperature is reached, turn to the STOP position to stop the
flow. Water may continue to flow from the handset for a few moments during
shut-down, as water is purged from the tank. Isolate the power at the double pole
switch.
11. A small amount of water may be retained in the shower fitting after the shower
control has been turned off. This may drain over a few minutes.
Note! A slight hissing sound may be heard from the appliance during operation.
High mains water pressure and high shower temperatures will effect the tone.
This is quite normal when the shower is in use.
21
Operation
Advice to Users
1. Electric showers work by taking in cold water and passing it over the heating
elements contained in the tank inside the shower.
2. The showering temperature is adjusted by turning the temperature control
knob, which varies the flow of cold water across the elements. The slower the
rate of flow, the warmer the water, and vice versa. The holes in the spray plate
of the shower handset should always be kept clean to maintain a consistent flow
and stable shower temperatures.
3. The appliance is designed to stabilise temperature changes caused by water
pressure fluctuations. These fluctuations can be caused by taps being turned
on or off, or toilets being flushed. Under such conditions, average shower
temperatures will be held within a 6°C range, provided that the minimum
required pressure is maintained.
4. Seasonal changes in the temperature of the incoming cold water supply and/
or fluctuations in mains electrical voltage will effect the temperature of the
water. Adjust the temperature knob as necessary to compensate.
5. The shower requires a minimum maintained/running pressure of 0.7 bar to
operate. At pressures above 0.7 bar, the shower will minimise the temperature
fluctuations caused when other draw-off points are used. If the flow rate drops
below an acceptable level, the heating element inside the shower will turn off,
resulting in a cold shower.
6. If the water temperature reaches an unsafe level, the thermal switch assembly
turns off the heating elements. As the water temperature falls the elements will
be turned on. The switch will cycle on/off/on if the flow rate is not increased and
the temperature of the shower reduced.
7. Check the shower temperature before entering the shower. The previous user
may have selected a different temperature setting.
8. When the shower is first turned on, or the temperature setting is changed, there
will be a slight delay before the water temperature changes.
22
Operation Instructions
Note! Read the Important Safety Information section first.
WARNING! The spray plate holes must be kept clear. The spray plate should be
regularly removed and cleaned in descalent. Lack of regular spray plate cleaning will
lead to poor performance and cause early failure of the appliance. See the shower
fittings User Guide for more information.
To turn the shower on
1. Switch on the electrical supply at the double pole
switch.
2. Turn the power knob to High. Wait 15–20 seconds
for warm water to reach the handset.
For electrical economy, set the power knob to
Medium. This setting will provide sufficient power
when the supply water temperature is warmer,
such as in the summer.
For an unheated shower, set the power knob to
Low.
To set the shower temperature
1. Set the shower temperature by rotating the
temperature knob as necessary. Turn the knob
clockwise for hotter water and anticlockwise for
cooler water. Wait 10–15 seconds for the adjusted
temperature to reach the handset.
Note! It is normal for the flow rate to change when
the temperature is changed.
Note! If the water temperature cycles between hot
and cold, the temperature is set too high. This is
causing the thermal switch to turn off the heating
element to reduce the water temperature. Turn
the temperature knob anticlockwise to reduce the
water temperature.
23
Cooler
Hotter
To turn the shower off
1. Turn the power knob to Stop.
Note! A small amount of water may continue to
flow from the handset for a few moments.
2. Switch off the electrical supply at the double pole
switch.
24
Fault Diagnosis
Customer Fault Diagnosis
The troubleshooting information below gives details on what you can do as a user if you
encounter problems with the shower. If this information does not fix the problem,
contact the installer for advice.
Read the Important Safety Information section first and refer to the appliance
diagram.
WARNING! There are no user-serviceable components beneath the cover of the
appliance. Only a competent tradesperson should remove the cover.
Malfunction Cause Remedy
Shower is too hot
during the summer.
Shower is too hot.
Turning the
temperature knob
does not affect the
water temperature.
The water continues
to flow when the
double pole switch
is turned off.
The incoming water is
warmer in the summer,
so the shower power
setting is too high.
The handset sprayplate
is blocked.
The handset sprayplate
is blocked.
Broken diaphragm.
Turn the power knob to
Medium and adjust the
temperature knob until the
desired temperature is
reached.
Regularly clean the handset
sprayplate. Refer to the
Maintenance section of the
handset manual.
Remove and clean the
handset sprayplate. Refer to
the Maintenance section of
the handset manual. If the
fault persists, contact the
shower installer.
Contact your installer to
replace the flow valve
assembly.
25
Malfunction
Cause Remedy
No water or very
low flow rate.
No hot water from
shower, with the
knobs in any
position.
Shower
temperature
cycles between
hot and cold.
The handset sprayplate
is blocked.
The incoming water
supply stop valves, or
the appliance isolating
valve, is closed.
The hose or handset is
blocked.
The power is off at the
double pole switch.
The fuse is blown or the
MCB/RCD has been
tripped, indicating a
possible electrical fault
Other water outlets are
being used during
showering, causing the
water pressure to drop
below the minimum
required.
The water pressure is
below the minimum
required.
Failure of pressure switch,
micro switch or thermal
switch.
The temperature is set
too high. This is causing
the thermal switch to
turn off the heating
element to reduce the
water temperature.
Clean the handset sprayplate.
Refer to the Maintenance
section of the handset manual.
Open the stop/isolating valve
completely.
Clear the blockage or replace
the hose or handset.
Switch on the power at the
double pole switch.
Renew the fuse or reset the
MCB/RCD. If the fault persists,
contact the shower installer.
Ensure the other water outlets,
such as the washing machine or
dishwasher, are not in use
during showering.
Ensure that the incoming water
supply stop and the isolating
valve are completely open. If
the fault persists, contact the
shower installer.
Contact installer to replace
faulty parts.
Turn the temperature knob
anticlockwise to reduce the
water temperature.
26
Installer Fault Diagnosis
The troubleshooting information below gives details on solutions to problems with the
shower, for installers. Before replacing any parts, ensure that the underlying cause
of the malfunction has been resolved.
Read the Important Safety Information section first and refer to the appliance
diagram.
Malfunction Cause
No hot water from
shower, with the
knobs in any
position.
Shower
temperature cycles
between hot and
cold.
Insufficient water supply
pressure.
Failure of the pressure
switch, microswitch or
thermal switch.
An internal wiring
connection has failed.
One of the heater tank
elements has failed.
Switch assembly
diaphragm fault, water
dripping from the unit.
The temperature is set too
high. This is causing the
thermal switch to turn off
the heating element to
reduce the water
temperature.
Remedy
Contact the local water
authority.
Check the continuity of the
switches, using a suitable
continuity measuring device.
Replace the switches as
necessary.
Check the integrity of the
internal wiring.
Replace the heater tank.
Replace switch assembly.
Turn the temperature knob
anticlockwise to reduce the
water temperature.
DO NOT TAMPER with the
thermal switch.
Turning the
temperature knob
does not affect the
water temperature.
The flow regulator is
faulty.
The handset sprayplate is
blocked.
27
Replace the flow regulator.
Remove and clean the
handset sprayplate. Refer to
the shower fittings User
Guide. If the fault persists,
contact Customer Services.
Malfunction
Cause Remedy
No water or very low
flow rate.
The handset sprayplate is
blocked.
The incoming water
supply stop valves, or the
appliance isolating valve,
is closed.
The hose or handset is
blocked.
Insufficient water supply
pressure.
The heater tank is
excessively scaled.
The pilot valve is faulty.
Regularly clean the handset
sprayplate. Refer to the
Maintenance section of the
handset manual.
Open the stop/isolating valve
completely.
Clear the blockage or replace
the hose or handset.
Contact the local water
authority.
Replace the heater tank.
Replace the flow regulator
assembly.
The inlet filter is blocked.
The power is not turned
on at the double pole
switch.
The fuse is blown or the
MCB/RCD has been
tripped, indicating a
possible electrical fault;
for example, heater tank
element failure.
28
Clean the inlet filter. See the
Maintenance: Cleaning the
Inlet Filter section.
Switch on the power at the
double pole switch.
Renew the fuse or reset the
MCB/RCD. If the fault
persists, contact Customer
Services. Replace the heater
tank.
Malfunction Cause Remedy
Water leaks from
the bottom of the
case near the
outlet, and there is
no flow from the
handset.
The water can not
be turned off.
The pressure relief valve
in the tank has been
triggered, (the shower
has a pressure relief
valve assembly that
works to reduce the
damage if the outlet is
blocked or the unit is
frozen).
When the relief valve
operates a small rubber
ball is ejected.
The pilot valve is faulty.
Broken diaphragm.
The supply pressure is
below the minimum
requirement.
Resolve the blocked outlet,
and replace the tank
assembly.
Reset the relief valve
assembly, refer to
Maintenance "Relief Valve
Setting"
If the fault persists, contact
Customer Services.
Replace the flow
regulator assembly.
Replace the flow regulator
assembly.
Contact the local water
authority.
Check the static water
pressure. Note that the static
pressure may fall below
minimum requirement when
other appliances are drawing
water; for example, the
dishwasher or washing
machine.
29
Maintenance
Any maintenance must be carried out by a qualified tradesperson, following the
instructions provided. Before replacing any parts, ensure that the underlying cause of
the malfunction has been resolved.
WARNING! There are no user-serviceable components beneath the cover of the
appliance. Only a competent tradesperson should remove the cover.
Cleaning
Many household and industrial cleaners contain abrasives and chemical substances
that can damage the finish of your shower. Only clean the shower and fittings with a
mild washing-up detergent or soap solution, and then wipe them dry with a soft cloth.
Cleaning the Inlet Filter
WARNING! Isolate the electrical and water supplies before removing the cover.
1. Remove the three screws that hold the cover on the shower and remove the
cover.
2. Remove the service tunnel from the shower.
Screws
Cover
Service Tunnel
Screw
30
3. Use a suitable spanner to remove
the filter from the inlet connector
assembly. Hold a wrench across
the flats of the inlet connector
assembly to prevent damage to the
connector, whilst removing the
strainer.
4. Remove the inlet filter.
5. Clean the inlet filter with a stiff
brush. If necessary, use a kettle
descalent in accordance with the
manufacturer's instructions.
6. Refit the components in reverse
order.
Inlet Filter
Inlet Connector
Assembly
Inlet Filter
Inlet Connector
Assembly
31
Relief Valve Assembly - Resetting
WARNING! Isolate the electrical and water supplies before removing the cover. Mains
electricity connections are exposed when the cover is removed.
1. Remove the three screws that hold the cover, remove the cover.
Note! The rubber ball is ejected to reduce the damage if the outlet is blocked or
the appliance is frozen.
2. Remove the five screws that hold the switch assembly, heater tank and, flow
regulator assembly.
Switch Assembly
Flow Regulator
Assembly
Ball
Screws
Heater
Tank
3. Lift out the switch assembly, heater tank and flow regulator assembly.
4. Using your finger push the ball back into the tank. Do not remove the 'O' seal.
Ball
5. Refit the components in reverse order.
6. Replace the cover. If the cover does not fit easily, rotate the knobs slightly so
that they fit into the spindles. Do not force the cover.
32
Flow Regulator Assembly/Switch Assembly- Removal and
Installation
WARNING! Isolate the electrical and water supplies before removing the cover. Mains
electricity connections are exposed when the cover is removed.
1. Remove the three cover retaining screws, the cover and the service tunnel.
2. Remove the hose from the outlet connector and loosen the connection to the
inlet connector.
3. Remove the six screws that hold the switch assembly, heater tank, flow regulator
assembly and inlet connector.
Screws
Shower
Service Tunnel
Cover
Screw
4. Remove all wiring from the spade connections on the switch assembly.
Note! Using long nose pliers, gently squeeze the lever lock and pull the
spade connection off the switch assembly.
Switch Assembly
Spade Connection
Lever Lock
33
5. Carefully pull off the two brown wires attached to the microswitch. Note the
position of the wires.
Microswitch
6. Carefully pull off the blue wire and brown wire from the solenoid, fitted to the flow
regulator. Note the position of the wires.
34
Solenoid
7. Carefully pull the flow regulator assembly, switch assembly and the heater tank
away from the case. Carefully separate the flow regulator from the switch assembly
and inlet connector by gently pulling apart.
Switch
Assembly
Heater
Tank
Inlet
Connector
Flow Regulator
Assembly
8. Refit the components in reverse order. Make sure that the electrical wires and ‘O’
seals are installed in the correct positions.
35
Heater Tank - Removal and Installation
WARNING! Isolate the electrical and water supplies before removing the cover. Mains
electricity connections are exposed when the cover is removed.
1. Remove the three cover retaining screws, the cover and the service tunnel.
2. Remove the hose from the outlet connector and ease the inlet connector off the
inlet supply pipe.
3. Remove the six screws that hold the inlet clamp bracket, flow regulator assembly,
switch assembly, and heater tank.
Switch Assembly
Screws
Heater
Tank
Flow Regulator
Assembly
36
Ball
4. Remove all wiring from the switch
assembly.
Note!
Using long nose pliers, gently
squeeze the lever lock on the top two
spade connection, and pull them off the
switch assembly. Carefully pull the two
lower connections off the switch
assembly.
5. Carefully pull off the blue wire to the
solenoid, fitted to the flow regulator.
Note the position of the wire.
Switch Assembly
Lever
Lock
Spade
Connection
6. Ease off both thin brown wires attached
to the microswitch. Note the position
of the wires.
37
Solenoid
Microswitch
7. Lift out the flow regulator assembly,
switch assembly and the heater tank
from the case.
8. Carefully separate the flow regulator
assembly from the switch assembly,
inlet connector and heater tank by
gently pulling apart.
9. Make a note of the positions of all the
wiring on top of the heater tank.
Inlet
Connector
10. Remove the screw that holds the
green earth wire to the thermal trip.
Switch
Assembly
Heater
Tank
Flow Regulator
Assembly
Thermal
Trip
11. Ease the thermal trip away from the
heater tank.
Caution! Do not press printed disc
on the thermal trip as this will make
the component unserviceable.
12. Remove the screw that holds the two
blue wires to the top of the heater tank.
13. Refit the components in reverse order.
Make sure that the electrical wires and
‘O’ seals are installed in the correct
positions.
Green Earth
Wire
Blue Neutral
Wire
38
Thermal Trip - Removal and Installation
WARNING! Isolate the electrical and water supplies before removing the cover. Mains
electricity connections are exposed when the cover is removed.
1. Remove the three cover retaining screws, and the cover.
2. Make a note of the positions of the wiring on top of the heater tank.
3. Remove the screw that holds the green earth wire to the thermal trip.
4. Ease the thermal trip away from the heater tank.
Brown
Red
Brown
Thermal Trip
Green Earth
Wire
5. Remove the screws that hold the red and three brown wires on the thermal trip.
6. Remove the thermal trip.
Caution! Do not press printed disc on the thermal trip as this will make the
component unserviceable.
Brown
Red
Brown
Thermal
Trip
7. Refit the components in reverse order. Make sure that the electrical wires are
installed in the correct positions.
39
Spare Parts
Spare Parts List
406.27 Filter
439.75 Inlet Connector Assembly
439.76 Clamp Bracket Pack (components identified ‘A’)
439.77 Flow Reg Assembly 7.5/8.5 kW
439.79 Switch Assembly, Rotary
439.81 Cover Assembly, Zest
439.87 Terminal Block Assembly
439.88 Seal Pack (components identified ‘B’)
439.89 Screw Pack (components identified ‘C’)
439.90 Thermal Trip Assembly
439.91 Heater Tank Assembly 7.5 kW
439.92 Heater Tank Assembly 8.5 kW
439.95 Service Tunnel
439.99 Tank Outlet and Ball
40
Spare Parts Diagram
439.79
439.87
439.75
B
406.27
A
A
C
B
439.77
C
B
439.90
C
B
439.95
C
439.99
439.91
439.92
439.81
41
Notes
42
Notes
43
Customer Service
Mira Showers guarantee products against any defect of
materials or workmanship for one year from the date of
purchase.
To validate the guarantee, please return your completed
registration card.
Within the guarantee period we will resolve defects, free of
charge, by repairing or replacing parts or modules as we may
choose.
To be free of charge, service work must only be undertaken
by Mira Showers or our approved agents in Northern Ireland
and Republic of Ireland.
Service under this guarantee does not affect the expiry date.
The guarantee on any exchanged parts or product ends when
the normal product guarantee period expires.
Not covered by this guarantee:
Damage or defects arising from incorrect installation, improper
use or lack of maintenance, including build-up of limescale.
Damage or defects if the product is taken apart, repaired or
modified by any person not authorised by Mira Showers or
our approved agents.
This guarantee is in addition to your statutory and other legal
rights.
Before using your shower
Please take the time to read and understand the operating
and safety instructions detailed in this manual.
What to do if something goes wrong
If when you first use your shower it doesn’t function correctly,
first contact your installer to check that installation and
commissioning are satisfactory and in accordance with the
instructions in this manual. We are on-hand to offer you or
your installer any advice you may need.
Should this not resolve the difficulty, simply contact our
Customer Services who will give every assistance, and if
necessary arrange for our service engineer to visit.
If later the performance of your shower declines, consult this
manual to see whether simple home maintenance is required.
Please call our Customer Services to talk the difficulty
through, request service under guarantee if applicable, or
take advantage of our comprehensive After-Sales service.
As part of our quality and training programme calls may be
recorded or monitored.
Our Customer Services Team is comprehensively trained to
provide every assistance you may need: help and advice,
spare parts or a service visit.
Spare Parts
We maintain an extensive stock of spares, and aim to have
functional parts available for ten years from the date of final
manufacture of the product.
Spares can be purchased from approved stockists or
merchants (locations on request) or direct from Customer
Services.
Spares direct will normally be despatched within two working
days. Payment can be made by Visa or Mastercard at the
time of ordering. Should payment by cheque be preferred a
pro-forma invoice will be sent.
Note! In the interests of safety, spares requiring exposure
to mains voltages can only be sent to competent persons.
Service
Our Service Force is available to provide a quality service
at a reasonable cost. You will have the assurance of a Mira
trained engineer/agent, genuine Mira spares – and a 12 month
guarantee on the repair.
Payment should be made directly to the Service Engineer/
Agent, using Visa, Mastercard or a cheque supported by a
banker’s card.
To contact us
England, Scotland & Wales
Mira Showers Customer Services
Telephone: 0870 241 0888
8:30 am to 5:00 pm Working days (4:30 pm Friday)
8:30 am to 12.30 pm Saturday
E-mail: technical@mirashowers.com
Fax: 01242 282595
By Post: Cromwell Road
Cheltenham
Gloucester GL52 5EP
Northern Ireland
Wm H Leech & Son Ltd
Telephone: 028 9044 9257 – Mon to Fri 9 am-5pm
Fax: 028 9044 9234 – 24 hours
Post: Maryland Industrial Estate
Ballygowan Road
Moneyreagh, Co Down
BT23 6BL
Republic of Ireland
Modern Plant Ltd
Telephone: Dublin 01 4591344 – Mon to Fri 9am to 5pm
Fax: Dublin 01 4592329 – 24 hours
Post: Otter House
Naas Road
Clondalkin
Dublin 22
Mira Showers
Kohler Mira Ltd
Cromwell Road,
Cheltenham GL52 5EP.
P4340 (J96E)
Mira is a registered trade mark.
The company reserves the right to alter
product specifications without notice.
www.mirashowers.com
44
© Kohler Mira Limited, November 2003
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