METHVEN KOHA SHOWER MIXER WITH FASTFLOW II User manual

www.methven.com
Technical Specifications:
Operating Pressure:
Unequal Pressure:
Hot: Min 17kPa
Cold: Min 300kPa
Equal Pressure:
Min 35kPa
If supply exceeds 500kPa a pressure
limiting valve must be installed.
Operating Temperature:
Hot: Min 55°C (at mixer), Max 80°C
Cold: Min 5°C
Inlet Connections:
All ½" BSP
* Regional specific regulations apply.
Please refer to your warranty statement
at www.methven.com
KOHA SHOWER MIXER WITH FASTFLOW II
Installation Guide

Mixer Body
Assembly
Nozzles
Refer to next
page for correct
nozzle selection.
Faceplate
O-ring
Grub Screw
Hex Key
Screws
Half Dome
O-ring
Faceplate Cover
Handle
IMPORTANT: Please read all of the instructions before installation.
General:
• Methven recommends this product is installed by a licensed plumber
in compliance with all relevant regional regulations.
• All pipe work must be thoroughly flushed prior to the installation of
the mixer.
• In-line filters must be fitted on both hot and cold supplies to prevent
foreign particles damaging the ceramic cartridge.
• After installation all connections must be checked for leaks.
• All outlets used primarily for personal hygiene shall deliver water at a
safe temperature as per regional regulations.
• This mixer is not recommended for use in uncontrolled heating
systems such as wet-backs or solar heating units unless a suitable
tempering valve is fitted.
• It is the responsibility of the installer to ensure a waterproof seal is
achieved between the product and mounting surface. If in doubt
about the quality of the seal, remove the product and reinstall using
silicone to ensure a seal is achieved.

Fitment of the primary nozzle into the mixer body
• Remove the dome cover (if fitted) and unscrew the lock nut.
• Take hold of the cartridge and with a gentle circular motion pull the cartridge straight out of the mixer body.
Note: Do not turn the cartridge.
• Fit the recommended nozzle into the cartridge as shown as per the table.
• Refit the cartridge ensuring that the 2 outer seals are in place. Refit the lock nut applying a torque of 12 Nm
and refit the dome cover.
JET SELECTION:
Equal Pressure Systems
Fit mixer as supplied.
Unequal Pressure Systems
If the system is supplied by a pressure pump, ensure that
the pump can maintain 300kPa at the cold Inlet. If not,
install a low pressure cold feed and install the mixer as if for
a low pressure equal system.
Use the following table to determine the nozzle to be used.
17-25 kPa Black
25-50 kPa Green
50-90 kPa Yellow
90-130 kPa Red
Hot Pressure Primary Nozzle
•
Step 2
For thin wall linings (eg acrylic showers):
• Position mixer body on horizontal support with the front edge of the black spacer flush with front of the
horizontal support.
• If necessary, loosen the plastic cover and leave in place during the installation.
For thicker wall linings (eg tiles):
• Remove black spacers from under the mounting bracket.
• Position mixer body on horizontal support with the front edge of the mounting bracket flush with front of
the horizontal support.
• Secure mixer body to the horizontal support with four suitable screws, ensuring it is oriented square.
• Alternatively, the mixer can be mounted to support timber behind the mixer maintaining the same
placement as above.
Step 3
• Flush all pipe-work thoroughly prior to the next step.
• Connect hot and cold supplies and outlet to mixer body ensuring a good seal at each joint.
• Leak test installation prior to closing wall cavity.
• The seal integrity of pipe joins is the responsibility of the installing plumber.
Step 1
• Refer to section above for correct nozzle selection.
• Install a horizontal support at the required height for correct positioning of the mixer.
Ensure front of horizontal support is in line with front of the framing.
Step 4
• Wall lining hole should be cut or finished as per the dimension shown in the diagram on the right.
• Allowable distance from front of horizontal support to finished wall surface:
– With spacer = 9 – 31mm
– Without spacer = 15 – 37mm
IMPORTANT: Before you begin, turn off the water supply.
Step 5
• Remove plastic cover. Do not discard the screws.
• Apply silicone to the faceplate to create a seal with the finished wall surface. Ensure the silicone
does not block the notch in the faceplate.
• Slide faceplate onto mixer body, and position faceplate with notch towards the bottom.
• Fasten faceplate to the mixer body with screws previously removed.
• Fit dome cover onto the mixer body.
• Push handle on to cartridge lever and tighten grub screw firmly with hex key provided.
Vertical Framing
Horizontal support
Front edge of spacer
Front edge of
mounting bracket
Outlet
Cold
Hot
100mm ±2 9 – 31mm
with spacer
15 – 37mm
without spacer

Methven warrants this product against manufacturing defects and that it is suitable for use
under the general operating conditions specified in this instruction sheet. However, regional
regulations apply and may affect your warranty. Please refer to www.methven.com or call
customer service for full details.
New Zealand
0800 804 222
Australia
1300 638 483
UK
0800 195 1602
Never use abrasives or abrasive cleaning agents to clean this product. Clean regularly with
contamination free warm soapy water and a damp soft cloth.
Care and Cleaning:
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