Submittal

Instantaneous production of hot water
Caleffi MixCal series 521 thermostatic mixing valves should not be used in conjunction with boilers giving 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 fi xtures 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 qualifi ed 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 specifi ed 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 fi lters 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.
Internal controlling components shall be accessible for repair without distrubing the pipe connections.
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”.
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.
Check valves
In order to prevent undersirable backsiphonage, separate check valves should be installed in systems with code “521 A” model
thermostatic mixing valves (these models do not contain integral check valves in the hot and cold inlet ports). As a convenience for easier
installations, the Caleffi code “521 A
C” model series thermostatic mixing valves include integral check valves in the hot and cold inlet ports.
NOTE TO INSTALLER: If the check valve is already installed in the tailpiece, remove the check valve and o-ring from the brass tailpiece before soldering
the tailpiece into place. Attach the o-ring to the check valve and install into tailpiece, pushing in until it bottoms out inside the tailpiece.
Commissioning
As In view of the special purpose of the thermostatic mixing valve, it must be commissioned in accordance with current standards by qualifi ed personnel
using temperature measuring equipment, Caleffi codes 521519A and 521619A with integral outlet port temperature gauges provide a time-saving
temperature setting process to get close to the desired temperture. Use of a digital thermometer is recommended for determining the fi nal setting of
the mixed water temperture.
NOTE: Gauge adapters with 2” diameter, 20-210ºF scale, code NA10056 (3/4” sweat) or NA10058 (1” sweat) can be separately purchased and fi eld
installed to the Caleffi MixCal series 521 models sold without the integral gauge adapters.
After installation, the valve must be tested and commisioned in accoprdance with instructions given below, taking into account current applicable
standards.
1) Ensure that the system is clean and free from dirt or debris before commissioning the thermostatic mixer.
2) It is recommended that the temperature is set using a suitable calibrated digital thermometer. The valve must be commissioned by measuring the
temperature of the mixed water emerging at the point of use.
3) The maximum outlet temperature from the valve must be set taking account of the fl uctuations due to simultaneous use. It is essential for these
conditions to be stabilised before commissioning.
4) Adjust the temperature using the adjusting knob on the valve. For safety reasons. it is advisable to limit the maximum mixed water temperature to
120ºF in domestic hot water systems.