Instructions

Instantaneous production of hot water
Caleffi Series 521 thermostatic mixers should not be used in
conjunction with boilers giving instantaneous production of
domestic hot water. Their addition would compromise the correct
operation of the boiler itself.
Installation
Before installing a Caleffi Series 521 mixer, the system must be
inspected to ensure that its operating conditions are within the
range of the mixer, checking, for example, the supply
temperature, supply pressure, etc.
Systems where the Caleffi Series 521 mixer is to be fitted
must be drained and cleaned out to remove any dirt or
debris which may have accumulated during installation.
Failure to remove dirt or debris may affect performance
and the manufacturer's product guarantee.
The installation of filters of appropriate capacity at the inlet
of the water from the mains supply is always advisable.
In areas which are subject to highly aggressive water,
arrangements must be made to treat the water before it
enters the valve.
Caleffi Series 521 mixers must be installed in accordance with the
diagrams in this manual, taking into account all current applicable
standards.
Caleffi Series 521 mixers can be installed in any position, either
vertical or horizontal.
The following are shown on the mixer body:
- Hot water inlet, colour red and marked “HOT”.
- Cold water inlet, colour blue and marked “COLD”.
- Mixed water outlet, marked “MIX”.
It is essential that access to the valve is totally unobstructed for
any maintenance which may be required to the valve or
connections. The pipework from/to the valve must not be used to
support the weight of the valve itself.
Use
Caleffi series 521 thermostatic mixing valves are designed
to be installed at the hot water heater. The Caleffi series 521
valve cannot be used for tempering water temperature at fixtures
as a point-of-use valve. They are not designed to provide scald
protection or anti-chill service. They should not be used where
ASSE 1070 devices are required. Wherever an scald protection
feature is required, Caleffi series 5213 high performance mixing
valve need to be installed. For safety reasons, it is advisable to
limit the maximum mixed water temperature to 120°F.