Install Instructions

Instantaneous production of hot water
Caleffi MixCal series 521 thermostatic mixing valves should not be used with boilers without storage
that give you instaneous production of domestic hot water. Their addition would compromise the
correct operation of the boiler itself.
Use
Caleffi MixCal series 521 thermostatic mixing valves are designed to be installed at the hot
water heater. The Caleffi Mix Cal 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 a scald protection
feature is required, Caleffi series 5213 high performance mixing valve needs to be installed. For safety
reasons, it is advisable to limit the maximum mixed water temperature to 120ºF.
Installation
NOTE TO INSTALLER: The Caleffi MixCal series 521 thermostatic mixing valve should be installed
by qualified personnel, in accordance with local codes and ordinances. It is the responsibility of
the installer to properly select, install and adjust this thermostatic mixing valve as specified in these
instructions.
Before installing a Caleffi MixCal series 521 thermostatic mixing valve, the system must be
inspected to ensure that it’s operating conditions are within the range of the thermostatic mixing
valve checking, for example, the supply temperature, supply pressure, etc.
Systems where the Caleffi MixCal series 521 thermostatic mixing valve is to be installed
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 area which are subject to highly aggressive water, arrangements must
be made to treat the water before it enters the valve.
Caleffi MixCal series 521 thermostatic mixing valves must be installed in accordance with the
diagrams in this manual, taking into account all current applicable standards.
Caleffi Mix Cal series 521 thermostatic mixing valves can be installed in any position, either vertical
or horizontal.
The following are shown on the mixer body:
– Hot water inlet, color red and marker “HOT”.
– Cold water inlet, color blue and marker “COLD”.
– Mixed water outlet, marker “MIX”.
M
I
N
M
A
X
7
1
2
3
Locking the setting
Position the handle to the number required
with respect to the index point. Unscrew the
head screw, pull off the handle and reposition
it so that the handle fits into the internal slot
of the knob. Tighten the head screw.
Index
Point