Mira Platinum Installation Manual page 13

An expansion vessel must be fitted (and regularly maintained) if any form of
backflow prevention device is fitted, e.g. non-return valve or PRV. This will ensure
that excess expansion or pulse pressures do not damage the product or plumbing
system. The expansion vessel may already be fitted within the boiler (check
with the manufacturer) and is in addition to the normally larger central heating
expansion vessel.
Use of Flow Regulators with Combination Boilers
The Mira Digital Mixer Valve can demand hot water quicker than some
instantaneous water heaters/combination boilers can provide, especially in winter
when the mains water is colder. A flow regulator may need to be used to ensure
that the Digital Mixer Valve can deliver a full range of water temperatures. The
table indicates the flow regulator to be fitted in the hot water inlet of the Mira
Digital Mixer Valve.
Boiler Rating 24 kW (80,000 Btu/h) 30 kW (100,000 Btu/h) 36 kW (120,000 Btu/h)
Flow Regulator 7 litres/min
Colour White Green
Unscrew hot inlet plastic nuts and remove pipe and seal to gain access to the
checkvalve cartridge and filter.
Use flat blade screwdriver to carefully lever cartridge out.
Fit flow regulator in checkvalve cartridge behind filter as shown.
Refit seal, pipe and plastic nut. Plastic nuts require hand tightening only.
Use of Warm-up Feature with Combination Boilers
When using the warm-up feature (see User Guide) with the Digital Mixer Valve
supplied via an instantaneous water heater/combination boiler, the user may
experience a brief temperature fluctuation. This is caused by the usual operation
of a standard instantaneous water heater/combination boiler whereby the boiler
will turn off when the flow is stopped (as happens after the warm-up sequence
has been completed). Upon restart of the shower, a cold shot will be flushed
through followed by a brief hot shot until the hot water supply has stabilised.
9 litres/min
White/Orange
13
Not required
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