rada Meynell V8/3 User manual

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Rada Meynell V8/3
Thermostatic Mixing Valve
Important! This Manual is the property of the customer and must be
retained with the product for maintenance and operational purposes.
Product Manual

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If you experience any difculty with the installation or operation of your new Mixing
Valve, then please refer to “Fault Diagnosis”, before contacting Kohler Mira Ltd.
Our telephone and fax numbers can be found on the back cover of this guide.
INTRODUCTION
The Meynell V8/3 is a Thermostatic Mixing Valve specied to meet the highest
standards of safety, and reliability as demanded by today’s users. All Meynell products
are designed, manufactured and supported in accordance with accredited BS EN
ISO 9001: 2000 Quality Systems.
This Manual covers all Meynell V8/3 Thermostatic Mixing Valves manufactured from
June 1997.
The sufx ‘3’ indicates that this mixer has been certied for use in UK Healthcare
premises as a Type 3 valve under the BUILDCERT TMV3 scheme. For Healthcare
installation refer to the TMV3 Requirements Manual.
The approved designations for Type 3 Valves are as follows:
Meynell V8/3 Model Designation.
Description Installation Temperature
Adjustment Finish
Meynell V8/3 Exposed or Built-In Short Lever
Adjustable Chrome
Meynell V8/3 L Exposed or Built-In Long Lever
Adjustable Chrome
Meynell V8/3 K Exposed or Built-In Locked Chrome
Model Designations
Rada Meynell V8/3 HP-S, HP-W, LP-S, LP-W
Important! The tting of any ow regulator will invalidate TMV3 compliance due to
the minimum ow rate requirements. Do not t ow regulators in TMV3 applications.

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Warning!
Products manufactured by us are safe provided they are installed, used and maintained
in good working order in accordance with our instructions and recommendations.
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. The plumbing installation must comply with the requirements of UK Water
Regulations/Bye-laws (Scotland), Building Regulations or any particular
regulations and practices, specied by the local water supplier. The installation
should be carried out by a plumber or contractor who is registered or is
a member of an association such as:
i) Institute of Plumbing (IOP), throughout the UK.
ii) National Association of Plumbing, Heating and Mechanical Services
Contractors (NAPH & MSC), England and Wales.
iii) Scottish and Northern Ireland Plumbing Employers’ Federation (SNIPEF),
Scotland and Northern Ireland.
6. Anyone who may have difculty understanding or operating the controls of any
appliance should be attended whilst operating. Particular consideration should
be given to the young, the elderly, the inrm, or anyone inexperienced in the
correct operation of the controls.
The use of the word “failsafe” to describe the function of a thermostatic mixing valve
is both incorrect and misleading. In keeping with every other mechanism it cannot
be considered as being functionally infallible.
Provided that the thermostatic mixing valve is installed, commissioned, operated
within the specication limits and maintained according to this Manual, the risk of
malfunction, if not eliminated, is considerably reduced.
Malfunction of thermostatic mixing valves is almost always progressive in nature
and will be detected by the use of proper temperature checking and maintenance
routines.
Certain types of system can result in the thermostatic mixing valve having excessive
‘dead-legs’ of pipework. Others allow an auxiliary cold water supply to be added
to the mixed water from the mixing valve. Such systems can disguise the onset of
thermostatic mixing valve malfunction.
Ultimately, the user or attendant must exercise due diligence to make sure that the
delivery of warm water is at a stable, safe temperature. This is particularly important
in such healthcare procedures as supervised bathing of patients unable to respond
immediately to unsafe temperatures.
SAFETY : WARNINGS

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PACK CONTENTS
Exposed Models
Tick the appropriate boxes to familiarize yourself with the part names and to
conrm that the parts are included.
1 x V8/3
1 x V8/3 L
1 x V8/3 K
1 x Hexagonal Key
3 x Fixing Screws
2 x 6 L/M Flow
1 x Compression Nut
Or
Or
Regulators
(Note! see section:
Type 2 and Type 3
Valves - Application)
1 x TMV3 Requirements Manual

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Built-in Models
1 x Hexagonal Key
3 x Fixing Screws
1 x V8/3 B
1 x V8/3 BL
1 x Foam Seal
1 x Rubber Grommet
1 x Concealing Plate
2 x 6 L/M Flow
Regulators
(Note! see section:
Type 2 and Type 3
Valves - Application)
1 x TMV3 Requirements Manual

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Normal Operating Conditions are considered as:
• inlet maintained pressures are nominally balanced
• daily usage 1-6 hours
• installation and usage environment not subject to extremes of temperature,
unauthorised tampering or wilful abuse.
Operating Parameters
For Type 3 installations, the supply conditions specied in the TMV3 Requirements
Manual take precedence over the operating parameters which follow.
Pressures And Flow Rates
For optimum performance, maintained supply pressures should be nominally
equal.
Maximum Pressure Loss Ratio: 10:1
Minimum Maintained Pressure: 0.1 bar (= 1 metre head from underside of cold tank
to outlet of shower tting)
Maximum Static Pressure: 10 bar
SPECIFICATIONS
0.1 0.2 0.3 0.4 0.5 1.0 2.0
0
5
10
15
20
25
30
35
40
45
Pressure Loss (bar)
Flow Rate (L/Min)
Thermostatic Mixing Valve
Temperature Control
Minimum temperature differential between hot and outlet temperature: 10°C
Optimum temperature control range: 35 - 45°C
Maximum hot water temperature: 85°C (for safety, a recommended hot water storage
temperature maintained below 85°C and for ablutionary installations at between
60 to 65°C).

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The performance specification outlined below is achieved with outlet blend
temperature set between 35 - 45°C and supplies of 15°C cold and 65°C hot with
nominally equal pressures.
• Outlet blend temperature is maintained within 2°C with a 10°C change in hot
or cold supply.
• Thermostatic shut down to seepage within 2 seconds if cold supply fails. This is
achieved only if the hot supply temperature is 10°C above the set outlet blend
temperature.
Connections
• Inlet connectors are 15 mm compression
• Outlet connector is 1/2” BSP Male or 15 mm compression
Hot (H) and Cold (C) inlets are clearly marked and must be connected this way.
Exposed Model
160 mm
130 mm Centres
122.5 mm
65 mm
35 mm
Dimensions
Built-in Model
161 mm
124 mm
55 mm MAX
35 mm MIN
122.5 mm
35 mm

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INSTALLATION REQUIREMENTS
Isolating Valve
Mixing Valve
Overow Indicator
Pressure Reducing Valve
Float Valve Twin Impeller Pump
Single Impeller Pump
Tempering Valve
Mini Expansion Vessel
Key to Symbols
The Meynell V8/3 Thermostatic Mixing Valve is compatible with the following
systems:
Gravity fed system
The Mixing Valve MUST be fed from a
cold water cistern and hot water cylinder
providing nominally equal pressure.
Gas heated system
The Mixing Valve MUST be installed with
a gas water heater or combination boiler
of a fully modulating design.

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Unvented mains pressure system
The Mixing Valve can be installed with a
unvented, stored hot water cylinder.
Mains pressurised instantaneous hot
water system (thermal store)
The Mixing Valve can be installed with
systems of this type with balanced
pressures.
Pumped system
The Mixing Valve can be installed with an
inlet pump (twin impeller). The pump must
be installed on the oor next to the hot
water cylinder.
Air Separation
30°-60°
90°

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INSTALLATION
General
Installation must be carried out in accordance with these instructions, and
must be conducted by designated, qualied and competent personnel.
The installation must comply with the “Water Supply (Water Fittings)
Regulations or Scottish Byelaws” or any particular regulations and practices,
specied by the local water company or water undertakers.
1. Before commencing, make sure that the installation conditions comply with
the information given in section: ‘Specications’. For Type 3 valves, see also
installation conditions in the TMV3 Requirements Manual.
2. Care must be taken during installation to prevent any risk of injury or damage.
3. The mixing valve should be positioned for easy access during use and
maintenance. All routine maintenance procedures can be conducted with the
mixing valve body in place (except for strainer and checkvalve access). For all
models, allow a minimum 80 mm clearance in front of the temperature control
to enable removal of the serviceable parts during maintenance. Conveniently
situated isolating valves must be provided for maintenance.
4. The use of supply-line or zone strainers will reduce the need to remove debris at
each mixing valve point. The recommended maximum mesh aperture dimension
for such strainers is 0.5 mm. Inlet pressure tappings which allow measurement
of inlet pressure to the mixing valve under operating conditions are particularly
recommended for healthcare with Type 2 and 3 valves.
5. Pipework must be rigidly supported.
6. Pipework dead-legs should be kept to a minimum. The mixed water outlet piping
should not exceed 2 m and the overall length from the hot water circuit to the
discharge point should not exceed 5 m.
7. Supply pipework layout should be arranged to minimise the effect of other outlet
usage upon the dynamic pressures at the mixing valve inlets.
8. Inlet and outlet threaded joint connections should be made with PTFE tape or
liquid sealant. Do not use oil-based, non-setting jointing compounds.
9. To eliminate pipe debris it is essential that supply pipes are thoroughly ushed
through before connection to the mixing valve.
10. The installation must comply with any particular regulations and practices,
specied by the local water supply regulations.

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25 mm
Spill Over
Level
Hose Retaining Ring
11. Decide on a suitable position for the
Mixing Valve. The position of the
Mixing Valve 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 back-siphonage. For
further information on the installation
of your shower ttings, refer to the
Fittings Installation and User Guide.
Note! Only use shower fittings
recommended by the manufacturer
or supplier.
Reverse Outlet Connector
If the Shower Outlet needs to be reversed (e.g. bottom outlet to top outlet):
1. Remove the Blanking Cap (if tted).
2. Using a 1/2” hexagonal key remove the Sealing Plug from the top and the Outlet
Connector from the bottom of the Thermostatic Mixing Valve.
3. Swap around and ret, if changing from at connector to compression make
sure that the ‘O’ Seal is changed around.
4. Ret in reverse order.
Coned End
Coned End
Flat End
Blanking Cap
Sealing Plug
‘O’ Seal
Outlet
Connector
Olive
Compression
Nut
‘O’ Seal
‘O’ Seal

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1. Exposed Models
1.1 Decide on a suitable position for the
Thermostatic Mixing Valve where all
users can operate it.
1.2 Remove the Wall Bracket from the rear
of the Mixer Valve Body by loosening
the Wall Bracket Grubscrew with a
2.5 mm hexagonal key (supplied).
1.3 Use the Wall Bracket to mark 3 hole
positions. Drill wall and insert suitable
Wall Plugs (not supplied) for No.10
Fixing Screws (supplied).
1.4 The Thermostatic Mixing Valve is
supplied for rising supplies.
For Falling or Rear Entry supplies
loosen the Elbow Grubscrew and
rotate the Elbow to the required
position. Then secure with the
Grubscrew.
1.5 Fit the supply pipework (Hot - Left,
Cold - Right).
Caution! It is essential at this point
that the supply pipework is thoroughly
ushed through before connection
to the Thermostatic Mixing Valve.
Failure to do so may result in product
malfunction.
1.6 Locate the Thermostatic Mixing Valve
onto the pipework and secure to the
Wall Bracket with the Grubscrew.
1.7 Tighten the Compression Nuts and
Olives using a suitable spanner.
1.8 Install the Shower Fittings, refer to
your Shower Fittings Installation and
User Guide.
1.9 Turn on the hot and cold water
supplies and check for leaks.
Hexagonal Key
Elbow
Inlet Pipework
Fixing Screws
Wall Bracket
Wall Plugs
(not supplied)
Inlet Pipework
(rear supplies)
35 mm
35 mm

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2. Built-in Models
2.1 Decide on a suitable position for the
Thermostatic Mixing Valve where all
users can operate it.
2.2 Determine the routes of the incoming
hot and cold supply pipework. They
can be rising or falling supplies.
2.3 Determine the route for the outlet
pipework. When connecting the
Shower Fittings to the outlet they
should be to the side and above the
Thermostatic Mixing Valve to make
sure that the Flexible Hose hangs
correctly and does not obstruct the
Shower Control. The outlet can be
sited on the right or on the left, as site
dictates.
2.4 Mark suitable routes for inlet and
outlet pipework.
2.5 Cut away plasterboard and brick
work to a depth of between 60 mm
to 80 mm. Depth should be 67 mm
min / 87 mm max including nish wall
thickness (tiles or facia board).
2.6 Fit the supply pipework
(Hot - Left, Cold - Right).
Caution! It is essential at this point
that the supply pipework is thoroughly
ushed through before connection
to the Thermostatic Mixing Valve.
Failure to do so may result in product
malfunction.
2.7 Fix the Thermostatic Mixing Valve
to the wall or timber noggin (refer to
section: ‘1. Exposed Models’ and
follow instructions 1.2 and 1.3).
2.8 Make the connections to the inlets
and outlet of the Thermostatic Mixing
Valve as shown
2.9 Tighten the Compression Nuts and
Olives using a suitable spanner.
2.10Turn on the hot and cold water
supplies and check for leaks.
ColdHot
Outlet
Shower
Outlet
Alternative
Routes

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2.11Plaster and tile up to the Thermostatic
Mixing Valve, leaving a maximum
diameter hole around the Mixing Valve
of 125 mm.
2.12 Fit the Sealing Grommet to the inner
diameter of the Concealing Plate.
Remove the protective backing from
one side of the Foam Washer and x
to rear of the Concealing Plate.
2.13 Unscrew the Control Knob Grubscrew
and remove the Control Knob.
2.14 Check that the Concealing Plate will
cover the installation hole.
2.15Peel the second protective backing
from the Foam Washer and t over
the Thermostatic Mixing Valve.
Push evenly on the Concealing
Plate to make sure that the adhesive
backing provides a sufcient seal.
2.16Ret and secure the Control Knob.
Sealing Grommet
Concealing
Plate
Foam Seal
Control Knob
Concealing Plate
(apply pressure
evenly)

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Temperature selection (not lockshield model).
The mixer has one control to set temperature and works in a sequence:
Off → Cold → Tepid → Pre-set Maximum
OPERATION
Preset Maximum
Temperature
Off

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COMMISSIONING
Commissioning must be carried out in accordance with these instructions, and must
be conducted by designated, qualied and competent personnel.
Exercising the Thermostat
Thermostatic Mixing Valves are inclined to lose their responsiveness if not used.
Valves which have been in storage, installed but not commissioned, or simply not
used for some time should be exercised before setting the maximum temperature
or carrying out any tests.
A simple way to provide this exercise is:
(a) make sure that the hot and cold water are available at the valve inlets,
and the outlet is open.
(b) move the temperature control rapidly from cold to hot and hot back to
cold several times, pausing at each extreme.
Commissioning Checks
(Temperatures should always be recorded using a thermometer with proven
accuracy)
1. Check the inlet pipework temperature for correct function of the checkvalves.
2. Operate the Meynell V8/3 and check:
• Flow rate is sufcient for purpose
• Temperature obtainable is acceptable
• All connections are watertight.
3. It is advisable to establish a performance check at this time, which should
be noted for future reference as part of a Planned Maintenance Program (a
Maintenance Record Card has been provided with this Manual).
The procedure should be chosen to imitate both typical and difcult operating
conditions, such as any supply pressure uctuations that may be likely. An ideal
method is to locate another outlet on the common cold water supply close to the
Thermostatic Mixing Valve (operating this outlet should cause a drop in supply
pressure), and note the subsequent effect on blend temperature. This should be no
more than 2°C change).
Note! Causing thermal shutdown of the Meynell V8/3 by full closure of the cold
supply may not adequately indicate the practical capability of the Meynell V8/3, nor
its service condition. Consequently this is not a recommended performance check,
and repeated such testing may ultimately affect service life.

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1. Turn on the Thermostatic Mixing Valve
to its maximum setting, (for Lockshield
models turn on the separate outlet
device tted eg. stopvalve). Let the
temperature stabilise.
2. Unscrew the Control Knob Grubscrew
and remove the Control Knob or
Lockshield.
3. Insert the 2.5 mm hexagon key into
the centre of Mixing Valve Head.
4. Turn the hexagon key anticlockwise
to increase the temperature, or
clockwise to decrease temperature.
5. Refit and secure the Control
Knob or Lockshield and turn off
the Thermostatic Mixing Valve (on
lockshield models turn off the outlet
device).
Note! The Control Knob should be
tted with the ‘brand’ horizontal.
Note! For Lockshield models make
sure that the anti-rotation slots
are engaged on the Lug on the
Mixing Valve Body (refer to arrow on
illustration).
Maximum Temperature
Note! For Type 3 valves in healthcare installations the maximum blend temperature
is determined by the application, refer to the TMV3 Requirements Manual.
The maximum blend temperature obtainable by the user should be limited, to prevent
accidental selection of a temperature that is too hot.
The Meynell V8/3 is fully performance tested, and the maximum temperature is preset
to approximately 42°C under ideal installation conditions at the factory.
Site conditions and personal preference may dictate that the maximum temperature
has to be reset following installation.
Maximum Temperature Setting
Make sure that an adequate supply of hot water is available at the hot inlet of the
Meynell V8/3 and that both inlet isolating valves are fully open.
The minimum temperature of the hot water must be at least 10°C above the desired
blend, however during resetting this should be close to the typical storage maximum
to offset the possibility of any blend shift due to uctuating supply temperatures.
Cooler
Warmer
Lockshield
Model

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FAULT DIAGNOSIS
Symptom Cause/Rectication
1. Only hot or cold
water from mixer
outlet.
a. Inlet supplies reversed (hot supply to cold supply).
b. No hot water reaching mixer.
c. Check strainers and inlet/outlet ttings for blockage.
d. Installation conditions continuously outside operating
parameters, refer to section: ‘Specications’ and 2.e
below.
2. Fluctuating or
reduced flow
rate.
Normal function of the thermostatic control when operating
conditions are unsatisfactory.
a. Check strainers and inlet/outlet ttings for blockage.
b. Make sure minimum ow rate is sufcient for supply
conditions.
c. Make sure the maintained inlet pressures are
nominally balanced and sufcient.
d. Make sure the inlet temperatures differentials are
sufcient.
e. (Subsequent to rectication of supply conditions)
Check thermostatic performance; renew Piston
Assembly if necessary.
3. No ow rate from
mixer outlet.
a. Check strainers and inlet/outlet ttings for blockage.
b. Hot or cold supply failure.
4. Blend temperature
drift.
Indicates operating conditions changed.
a. Refer to symptom 2. above.
b. Hot supply temperature uctuation.
c. Supply pressures uctuating.
d. Seal damage or wear. Renew seals.
5. Maximum blend
temperature
setting too hot or
too cold.
a. Indicates incorrect maximum temperature setting;
refer to section: ‘Commissioning’.
b. As symptom 4. above.
6. Water leaking
from mixer body.
Seal wear or damage.
a. Obtain Seal Kit, renew all seals.
7. Flow rate too high
or too low.
a. (Too low) Refer to symptom 2.a-e. above.
b. (Too low) Insufcient supply pressures.
c. (Too high) Supply pressure too high.
d. (Too high) Refer to symptom 2.a-e. above.

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MAINTENANCE
General
This Product is precision engineered and should give continued safe and controlled
performance, provided:
1. It is installed, commissioned, operated and maintained in accordance with
manufacturers recommendations.
2. Periodic attention is given, when necessary, to maintain the product in good
functional order.
The Rada Meynell V8/3 is designed for the minimum of maintenance in normal use.
The only serviceable parts are the inlet lters which should be checked and cleaned
every 12 months. If a malfunction occurs with the Thermostatic Cartridge then this
will necessitate a complete cartridge replacement.
Note! The cartridge contains no internally serviceable parts.
If you require a Rada trained engineer or agent, refer to section: ‘Customer Service’.
Planned Maintenance
Important! For Type 3 Valves use the In-Service Tests given in the TMV3
Requirements Manual. In the absence of any other instruction or guidance on the
means of determining the appropriate frequency of in-service testing, the procedure
contained within this guide (taken from Annex F of D08) should be used.
For other commercial installations it is recommended that the correct blend setting
is checked every 6 months and that the In-Service Test procedure is followed every
12 months.
Critical Components
Irrespective of supply and usage conditions or the evidence of in-service tests, critical
components should be replaced at intervals of no more than 5 years.
Note! During the replacement of critical components, it may be necessary to replace
other non-critical components.
Lubricants
Silicone based lubricants must only be used on the rubber seals.
Caution! Oil based or other lubricant types may cause rapid deterioration of seals.
Cleaning
The chrome plated parts should be cleaned using a mild washing up detergent or
soap solution, rinsed and then wiped dry with a soft cloth.
Warning! Many household cleaners contain abrasive and chemical substances, and
should not be used for cleaning plated or plastic ttings. Do not use descalents on
this product.