Kohler rada VZ1 10 User manual

11320703-W2-B
Installation and User Guide
IMPORTANT
Installer: This Manual is the property of the customer and must be retained with
the product for maintenance and operational purposes.
RADA VZ1 10 Thermostatic Bar Valve
For SPARES,
ADVICE or REPAIRS
please call us free
on 0344 571 1777
(UK only)
Affix Sticker Here
Model Name:
Product Code:
Date of Manufacture:
(Your guarantee information is included in this guide. Please keep these details
safe as you will need them when registering your product guarantee.)

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Thank you for choosing a quality Rada product. To enjoy the full potential of your
new product, please take time to read this guide thoroughly, and keep it handy for
future reference. Products manufactured by Kohler Rada Ltd. are designed to be
safe, provided that they are installed, used and maintained in good working order,
in accordance with our instructions and recommendations.
Follow all warnings, cautions and instructions contained in this guide, and on, or
inside the shower. This guide is also available in digital format from our website or
by contacting customer services.
The Rada VZ1 10 is a thermostatic shower valve with a separate control lever for
on/o󰀨 and temperature control.
The Rada VZ1 10 incorporates a wax capsule temperature sensing unit which
provides an almost immediate response to changes in pressures or temperature of
the incoming water supplies to maintain the selected temperature. An adjustable
maximum temperature stop is provided which limits the temperature to a safe level.
Inlet lters are tted to protect the thermostatic cartridge.
Introduction
We guarantee this product against any defect in materials or workmanship for a
period of one year from the date of purchase.
Failure to follow the instructions provided with the shower will invalidate the
guarantee. For terms and conditions, refer to the customer service page.
Guarantee
Type 2 Valves
This product has been certied as a Type 2 valve. It also complies with the Water
Supply (water ttings) regulations 1999. For further information on Type 2 Valves,
refer to the TMV2 Requirements Manual (available to view or download on our
website www.radacontrols.com). The approved designation for this product is
listed in the table below.
Rada product covered by this guide:
Product Code Model Number Colour Type 2 Designation
N06A Rada VZ1 10 Chrome HP-S
If you experience any difficulty with the installation or operation of your new
thermostatic mixer, please refer to ‘Fault Diagnosis’, before contacting Rada.
Our contact details can be found on the back cover of this guide.

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Pack Contents
2 x Wall Brackets1 x Plastic Pipe Guide
2 x Concealing Plates
2 x Compression Nuts2 x Olives
2 x Wall Plugs 2 x Fixing Screws
1 x Component Pack, Containing:
Documentation
1 x Installation and User Guide
1 x Bar Valve
1 x 6 l/min
Flow Regulator
1 x Pair of Handles
2 x Sealing Washers

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Dimensions
135 mm
ø70 mm 45 mm
150 mm
83 mm
HOT COLD
300 mm

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Design Registration: GB 001225254-0003
Patents: GB 2 407 138
Domestic 
Light Commercial 
Heavy Commercial 
Healthcare 
Design Registration and Patents
Recommended Usage
PLEASE OBSERVE THE FOLLOWING TO REDUCE THE RISK OF INJURY:
Installing the Shower
1. Installation of the shower must be carried out in accordance with these
instructions by qualied, competent personnel. Read all instructions before
installing the shower.
2. DO NOT install the shower where it may be exposed to freezing conditions.
Ensure that any pipework that could become frozen is properly insulated.
3. DO NOT perform any unspecied modications to the shower or its accessories.
When servicing only use genuine Kohler Rada replacement parts.
4. If the shower is dismantled during installation or servicing then, upon completion,
an inspection must be made to ensure all connections are tight and that there
are no leaks.
Safety Information
WARNING ! This shower can deliver scalding temperatures. For continued
safe operation, follow all instructions, warnings and cautions contained
in this guide and on or inside the shower. Periodic maintenance may be
required to keep the product in good working order.
The function of a thermostatic mixing valve is to deliver water consistently
at a safe temperature. In keeping with every other mechanism, it cannot
be considered as functionally infallible and as such, cannot totally
replace a supervisor’s vigilance where that is necessary. Provided it is
installed, commissioned, operated and maintained within manufacturers
recommendations, the risk of failure, if not eliminated, is reduced to the
minimum achievable.

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Using the Shower
5. The shower must be operated and maintained in accordance with the
requirements of this guide. Make sure you fully understand how to operate
the shower before use, read all instructions and retain this guide for future
reference.
6. DO NOT switch the shower on if there is a possibility that the water in the shower
unit or ttings is frozen.
7. The shower can be used by children aged from 8 years and above and persons
with reduced physical, sensory or mental capabilities or lack of experience and
knowledge if they have been given supervision or instruction concerning use
of the appliance in a safe way and understand the hazards involved. Children
must not be allowed to play with the shower.
8. Anyone who may have di󰀩culty understanding or operating the controls of any
shower should be attended whilst showering. Particular consideration should
be given to the young, the elderly, the inrm or anyone inexperienced in the
correct operation of the controls.
9. DO NOT allow children to clean or perform any user maintenance to the shower
unit without supervision.
10. Always check the water temperature is safe before entering the shower.
11. DO NOT adjust the temperature control rapidly while using the shower.
12. Use caution when altering the water temperature while in use, always check
the temperature before continuing to shower.
13. DO NOT switch the shower o󰀨 and back on while standing in the water ow.
14. DO NOT t any form of outlet ow control. Only Rada recommended outlet
ttings should be used.
15. The showerhead must be descaled regularly. Any blockage of the showerhead
or hose may a󰀨ect showering performance.
16. The water supplies to this product must be isolated if the product is not to be
used for a long period of time. If the product or pipework is at risk of freezing
during this period they should also be drained of water.
17. When this product 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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• For safety and comfort the thermostat will shut o󰀨 the mixing valve within
2 Seconds if either supply fails (achieved only if the blend temperature has
a minimum di󰀨erential of 12°C from either supply temperature).
Thermostatic Shut-down
Temperatures
Close temperature control 20°C - 50°C
Optimum Thermostatic Control
Range
35°C to 45°C
(achieved with supplies of 15°C cold, 65°C hot and
nominally equal pressures)
Recommended Hot Supply 60°C to 65°C
Minimum Hot Water Supply Tem-
perature
55°C
(Note: The mixing valve can operate at temperatures
up to 85°C for short periods without damage.
However for safety reasons it is recommended that
the maximum hot water temperature is limited to
65°C)
Minimum Recommended
Di󰀨erential between Hot Supply
and Outlet Temperature
12°C at desired ow rates
Cold Water Range 1 - 25°C
Specications
Pressures
Maximum Static Pressure 1000 kPa (10 bar)
Maximum Maintained Pressure 500 kPa (5 bar)
Minimum Maintained Pressure
(Gas Water Heater)
100 kPa (1 bar)
(for optimum performance supplies should be
nominally equal)
Minimum Maintained Pressure
(Gravity System)
10 kPa (0.1 bar)
(0.1 bar = 1 Metre head from cold tank base to shower
handset outlet)
Plumbing Connections
Hot: Left 15mm pipework, 3/4" BSP to valve
Cold: Right 15mm pipework, 3/4" BSP to valve
Outlet: Bottom 1/2" BSP Male

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Flow Rates
Typical Flow Rates on Low Pressure System (0.1 bar to 1 bar)
*Note: Pressure Loss = Inlet Pressure - Outlet Pressure (measured at valve outlet)
with 6 L/min Flow Regulator
Outlet Temperature = 39°C
65/15°C Inlet Temperature
Flow Rate (L/min)
Pressure loss (bar)*
0
5
10
15
20
25
30
35
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

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Warning! This product does not allow for reversed inlets and will deliver
unstable temperatures if tted incorrectly.
Installation
General
1. Installation of the shower must be carried out in accordance with these
instructions by qualied, competent personnel.
2. The plumbing installation must comply with all national or local water regulations
and all relevant building regulations, or any particular regulation or practice
specied by the local water supply company.
3. Make sure all pressures and temperatures comply with the requirements of the
shower. See ‘Specications’. For Type 2 Valves, refer to supply conditions
given in the TMV2 Requirements Manual (this is available to view or
download from our website www.radacontrols.com).
4. Full bore/non restrictive servicing valves must be tted in a readily accessible
position adjacent to the shower to facilitate maintenance of the shower.
DO NOT use a valve with a loose washer plate (jumper) as this can lead to a
build up of static pressure.
5. DO NOT apply excessive force to plumbing connections; always provide
mechanical support when making plumbing connections. Any soldered joints
should be made before connecting the shower.
6. Pipework dead-legs should be kept to a minimum.
7. DO NOT install the shower unit in a position where access for maintenance is
restricted.
8. The shower must be tted to a waterproof, at and even wall surface. The
two screws and wall plugs supplied are suitable for most solid wall installations.
Alternative xing screws for panel structures are not supplied. Use both xing
points to secure the shower, be sure to use xings appropriate for the chosen
wall structure.
9. When pipework enters the product from the rear through a hole in the wall,
provision must be made to prevent water ingress back into the wall structure.
10. Position the shower unit where the controls are at a convenient height for the
user. Position the showerhead so that the water sprays in line with the bath or
across the opening of a shower cubicle. The installation must not cause the
shower hose to be kinked during normal use.
Suitable Plumbing Installations
The Thermostatic Mixer can be installed with all systems with balanced pressures.
Mixed gravity and mains supplies are not recommended.

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11. The water supplies to this product should be isolated if the product is not to be
used for a long period of time. If the product or pipework is at risk of freezing
during this period they should also be drained of water.
12. The position of the shower and shower ttings must provide a minimum air
gap of 25 mm between the showerhead and the spill over level of any bath,
shower tray or basin. There must be a minimum distance of 30 mm between
the showerhead and the spill over lever of any toilet, bidet or other appliance
with a Fluid Category 5 backow risk.
Zone of
Backflow
Risk
30 mm
Minimum
Toilet or Bidet
FC5
Hand Basin
FC3
Bath or Shower
Tray FC3
Shower
Unit
25 mm
Minimum
25 mm Minimum
Note : There will be occasions when the hose retaining ring will not provide a suitable
solution for Fluid Category 3 installations. In these instances an outlet double
checkvalve must be tted, this will increase the required supply pressure typically
by 10 kPa (0.1 bar). Double checkvalves tted in the inlet supply to the appliance
cause a pressure build up, which a󰀨ects the maximum static inlet pressure for the
appliance and must not be tted. For Fluid Category 5, double checkvalves are
not suitable.

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Wall Bracket
8 mm
Plastic Pipe
Guide
25 mm
25 mm
HOT
COLD
150 mm
Fit the plastic pipe guide over the inlet
pipes. Level the pipe guide and secure
to the wall to hold in position. Leave
the guide in place and nish the wall.
Installation of Bar Valve
Ø6 mm
Note: Connections are; Hot-Left,
Cold- Right.

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Install the olives and the connectors.
Tighten nger tight and then another
1/4 to 1/2 turn. Turn on the water supply and ush the
pipework.
Note: Fit the handles. See Instructions on the box in which the handles
are packed.
Install the ow handle.
Install the temperature handle.
Attach the bar valve to the wall xings.
Note: Make sure that the sealing
washer/filter is installed in each
inlet.
Note: Supplied olives must be
used. Ensure pipe manufacturer’s
instructions are followed (i.e. use
pipe inserts for plastic pipe).

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Install the shower ttings, refer
to the Installation Guide packed
with the product.
Check for leaks on all connections
you have made.
A 6 l/min ow regulator can be tted into the outlet.
Shower Hose
Flow Regulator
Washer
Mixing
Valve
Note: Orientate ow regulator as shown
above.
Commissioning
Maximum Temperature Setting
Before using the shower, the maximum temperature must be checked to make sure
that it is at a safe level. It has been preset to a safe showering temperature under
ideal conditions at the factory, appropriate for most systems. However, site conditions
and personal preference may make it necessary to reset this temperature.
1. Turn the temperature handle anticlockwise until it stops and test that the
temperature of the water from the shower outlet is hot enough.
2. If not, depress the override button and carefully rotate the handle further. If the
water temperature is still not hot enough complete the following procedure.
3. Rotate the temperature selector handle back to the override position.
4. Remove temperature handle by pressing the override button and pulling the
handle.
Note: Make sure that the hot water temperature is at least 55°C and that
there is su󰀩cient supply.
Caution! Before testing the mixer, make sure that the hot and cold water
is owing correctly by exercising the temperature handle from hot to cold.
Note: The end
cap on the Assist
handles must be
removed before
pulling o󰀨. Temperature
Handle
Override
Button
End Cap

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5. Remove the xing screw holding on the handle attachment components using a
3 mm Allen key. Remove the two attachment components.
6. Temperature adjuster can be moved 3 positions in either direction, one position
equals 1˚C. Rotate adjuster anti-clockwise to increase temperature and rotate
clockwise to decrease temperature.
7. Replace the attachment components and make sure the xing screw is fully
tightened. Ret the handle.
Maximum Temperature Position
Location Pin
Factory Setting
Location Pin
Cleaning
Many household and commercial cleaners, including hand and surface cleaning
wipes contain abrasives and chemical substances that can damage plastics, plating
and printing and should not be used. These nishes should be cleaned with a mild
washing up detergent or soap solution, and then wiped dry using a soft cloth.
Important! The showerhead must be de scaled regularly, keeping the showerhead
clean and free from lime scale will ensure that your shower and showerhead continue
to perform to their maximum. A blocked showerhead can restrict the ow rate and
may cause damage to your shower.

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Adjusting the Temperature
The temperature is controlled by rotating the temperature handle. For safety reasons,
the temperature is limited by an override stop. To obtain a higher temperature, press
the override button on the temperature handle and continue to rotate the handle.
Temperature
Handle
Temperature
Override Button
OFF
ON
Decrease
Temperature
Increase
Temperature
Operation
Adjusting the Flow
The ow is controlled by rotating the ow handle.

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Fault Diagnosis
Symptom Cause / Rectication
Water too hot or too cold Inlets reversed (hot supply to cold supply).Rework inlet pipework.
Check lters for any blockage.
Check the maximum temperature setting (If you have a combination type
boiler it may not be producing su󰀩cient hot water at the desired ow rate).
Fit a ow regulator to the shower valve outlet.
Installation conditions outside operating parameters. Refer to Specications
and Commissioning.
Poor temperature
control
Make sure that the inlet temperature di󰀨erentials are su󰀩cient, refer to
‘Specications’.
If tted to a combi boiler ensure there is su󰀩cient pressure and ow to
deliver a constant hot water inlet supply.
Check the shower handset, hose and inlet lters for any blockage and
clean where necessary.
Fluctuating or reduced
ow
Check the shower handset, hose and lters for any blockage.
Make sure that the maintained inlet pressures are nominally balanced
and su󰀩cient. Refer to Specications.
Air lock or partial blockage in the pipework.
Water leaking from
the shower handset/
overhead
Normal for a short period after shut o󰀨.
Check that the pressures are not in excess of the specications for this
product.
There may be occasions where the overhead shower or shower handset
empties for a while after the shower has been used, this is due to changes
in ambient temperatures and is normal. It is recommended that all outlets
are therefore enclosed within the water catchment area.
If you require a Rada trained service engineer or agent, refer to ‘Customer Service’.
What to do if something goes wrong
If your product does not work correctly check that it is installed and commissioned
in accordance with our instructions. If this does not resolve the issue, contact us for
help and advice. Refer to Customer Service page for more details.

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Spare Parts
1836.174
Inlet Seal / Filter
1836.179
Fixing Kit
1900.070
Concealing Plates
1900.069
Handle Attachment
Pack
1900.077
Flow Regulator Kit (2 x 6 L/min)
(Not Illustrated)
1900.069
Handle Attachment
Pack
1900.051
Single Outlet Valve
1900.068
1 x Pair of Handles

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Notes

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Notes

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Customer Services Guarantee
Your product has the bene t of Rada’s comprehensive parts and labour
manufacturer’s guarantee which commences from date of purchase. Full
guarantee terms and conditions can be found at www.radacontrols.com or
contact your in region Rada representative or sales agent for further details.
Contact Us
If your product is not working correctly please refer to this manual for fault
diagnosis and to check that it is installed and commissioned in accordance
with our instructions. If this does not resolve the issue, then please contact
our specialist teams who will be happy to help.
For UK based customers support please contact Rada Customer Services
T: + 44 (0)344 571 1777 Please note: UK calls cost 7p per minute plus your
phone company’s access charge
E: [email protected]
www.radacontrols.com
For customers based in the Republic of Ireland please contact our Rada
Service agent
T: + 353 (0) 1 531 9337
E: [email protected]
For customers based in all other geographical regions please get in touch with
your local Rada representative or agent whose contact details can be found
by visiting our website www.radacontrols.com/en/contact-us/ nd-a-partner
Services
Our UK Rada Customer Service Team can provide pre-specification
information as well as details on the UK Rada product Commissioning
Service and Maintenance Service Plans whilst our nationwide team of
 eld-based technicians are here to help if you need a Reactive Service Call.
We stock a full range of Rada spare parts and  ttings which can be purchased
over the telephone.
Note! Regional services do vary please speak to your Rada representative
or Sales agent for information on service provisions provided in your area.
Rada is a registered trade mark
of Kohler Mira Limited.
The company reserves the right
to alter product specifi cations
without notice.
EU Importer address
K/E S.A.S.
3 rue de Brennus,
93631, La Plaine Saint-Denis,
France
Registered O󰀩 ce:
Cromwell Road,
Cheltenham,
Gloucestershire
GL52 5EP 14648
1473740-W6-A
© Kohler Mira Limited, January 2022
Customer Service