CALEFFI MixCal 521 Series Guide

Technical Characteristics
Materials: -Body: low-lead brass (<0.25% lead content)
-Shutter, seats and sliding guides: PPO
-Springs: stainless steel
-Seals: peroxide-cured EPDM
Suitable fluids: water, 30% max glycol solution
Setting range (outlet temperature): 85–150°F (30–65°C)
Tolerance: ±3°F(±2°C)
Max. working pressure (static): 200 psi (14 bar)
Max. operating differential pressure (dynamic): 75 psi (5 bar)
Max. recommended differential pressure: 20 psi (1.5 bar)
Max. hot water inlet temperature: 200°F (93°C)
Max. inlet pressure ratio (H/C or C/H) for optimum performance: 2:1
Min. temperature difference between hot water inlet and mixed
water outlet for optimum performance: 27ºF (15ºC)
Min. flow rate to ensure optimal performance: 1.0 GPM (3.8 L/min)
Lay length, hot to cold inlet: (½” & ¾” press connection) 3 5/8”
(1” press connection) 4 1/8”
Certified to: 1. ASSE 1017/CSA B125.3, certified by ICC-ES, file
PMG-1357
2. NSF/ANSI 372-2011, Drinking Water System
Components-Lead Content Reduction of Lead in
Drinking Water Act, California Health and Safety
Code 116875 S.3874, Reduction of Lead in
Drinking Water Act, certified by ICC-ES, file
PMG-1360.
Function
The Caleffi MixCal™ three-way thermostatic mixing valve is used in
systems producing domestic hot water or in hydronic and radiant
heating systems. With the unique mixing chamber design, MixCal™
produces very stable mixed water temperture as inlet temperatures
and pressures vary. Scale formation is minimized with anti-scale
polymer sliding surfaces, preventing siezing or erratic mixed
temperatures. O-ring seals made from durable peroxide-cured EPDM
resist wear from common water treatment additives such as chlorine
and chloramines.
Product range
521A Series Three-way thermostatic mixing valve:
“C” models include inlet check valves. “419, 519, 619” models include
outlet gauge adapter. Connections: union thread NPT male, sizes ½”,
¾”, 1”; union sweat, sizes ½”, ¾”, 1”; union press, sizes ½” , ¾”, 1”;
union PEX crimp, sizes ½” , ¾”, 1”.
MixCal™Adjustable three-way thermostatic mixing valve
521 series
© Copyright 2017 Caleffi
38476.10
www.caleffi.com
INSTALLATION AND COMMISSIONING MANUAL
1

Leave this manual for the user.
CAUTION: If the thermostatic mixing valve is not installed, commissioned
and maintained properly, according to the instructions contained in this
manual, it may not operate correctly and may endanger the user.
CAUTION: Make sure that all the connecting pipework is water tight.
CAUTION: When making the water connections, make sure that
the pipwork connecting the MixCal™ thermostatic mixing valve is not
mechanically overstressed. Over time this could cause breakages, with
consequent water losses which, in turn, could cause harm to property and/
or people.
CAUTION: Water temperatures higher than 100ºF (38ºC) can be
dangerous. During the installation, commissioning and maintenance of
the MixCal™ thermostatic mixing valve, take the necessary precautions to
ensure that such temperatures do not endanger people.
CAUTION: To prevent any damage which will cause the electronic mixing
valve to not operate correctly, treat highly aggressive water before entering
the electronic mixing valve. Be sure water hardness is less than 10 grains.
CAUTION: If installed in an ASSE 1017 application, check valves
shall be used.
SAFETY INSTRUCTION
CAUTION: All work must be preformed by qualied personnel trained
in the proper application, installation, and maintenance of systems in
accordance with all applicable codes and ordinances.
This safety alert symbol will be used in this manual to draw attention to safety related
instructions. When used, the safety symbol means ATTENTION! BECOME ALERT!
YOUR SAFETY IS INVOLVED! FAILURE TO FOLLOW THESE INSTRUCTIONS MAY
RESULT IN A SAFETY HAZARD.
2

ATTENTION: Lorsque vous effectuez les raccordements d'eau, assurez-
vous que la tuyauterie reliant le MixCal™ termostatico regolabile n'est pas
mécaniquement des overstressed. Au fil du temps, ceci pourrait causer des
ruptures, avec pour consequence des pertes en eau qui, à leur tour, peuvent
causer des dommages à la propriété et/ou les gens.
Ce symbole d'avertissement servira dans ce manuel à attirer l'attention sur la sécurité concernant
instructions. Lorsqu'il est utilisé, ce symbole signifie.
ATTENTION! DEVENEZ ALERTE ! VOTRE SÉCURITÉ EST EN JEU ! NE PAS SUIVRE CES
INSTRUCTIONS PEUT PROVOQUER UN RISQUE DE SECURITE.
ATTENTION: Tous les travaux doivent être effectués par du personnel
qualifié formé à la bonne application, installation et maintenance des systèmes
conformément aux codes et règlements locaux.
ATTENTION::Si le réducteur de pression, termostatico regolabile, n'est pas installé,
mis en service et entretenu correctement, selon les instructions contenues dans ce
manuel, il peut ne pas fonctionner correctement et peut mettre en danger l'utilisateur.
ATTENTION: S'assurer que tous les raccordements sont étanches.
ATTENTION: Les températures de l'eau supérieure à 100°F (38°C) peut
être dangereux. Au cours de l'installation, mise en service et l'entretien de
le réducteur de pression, le MixCal™ termostatico regolabile, prendre les
precautions nécessaires afin de s'assurer que de tells températures ne
compromettent pas les gens.
ATTENTION: Pour prévenir tout dommage qui provoque le mitigeur
électronique à ne pas fonctionner correctement, le traitement de l’eau très
agressive avant d’entrer dans la vanne de mélange électronique. Assurez-
vous que la dureté de l’eau est inférieure à 10 grains.
ATTENTION: S’il est installé dans un pays de ASSE1017 application, vérifiez les
robinets doivent être utilisés.
CONSIGNE DE SÉCURITÉ
LAISSEZ CE MANUEL AVEC L’UTILISATEUR
3

COLD
HOT
MIX
COLD
HOT
MIX
Operating principle
The controlling element of the three-way
thermostatic mixing valve is a thermostatic
sensor fully immersed in the mixed water
outlet tube which, as it expands or contracts,
continuously establishes the correct proportion
of hot and cold water entering the valve. The
regulation of these flows is by means of a
piston sliding in a cylinder between the hot
and cold water passages. Even when there
are pressure drops due to the drawing off of
hot or cold water for other uses, or variations
in the incoming temperature, the thermostatic
mixing valve automatically regulates the water
flow to obtain the required temperature.
COLD
HOT
MIX
Inlet port check valve detail for 521 “AC” models
Flow curve
Flow should never exceed standards for pipe size and materials.
Kv = 2.6
0.1
10
0.023
0.23
0.046
0.069
0.02 0.05 0.2 0.5
0.115
2.3
0.46
0.69
1.15
20 50
∆p (ft of head)
G (l/min) (
gpm
)
23
4.6
6.9
11.5
46
0.01
0.1
0.02
0.03
0.05
1
0.2
0.3
0.5
(psi) (bar)
10
2
3
5
20
1 0
.1
0.2
0.5 0.05 10
2 5 20
0.001
0.01
0.002
0.003
0.005
0.1
0.02
0.03
0.05
1.0
0.2
0.3
0.5
Cv = 3.0
9.2
0.092
0.92
0.04
0.4
4
0.004
0.04
0.4
50
115
161
50
70
2.0
5.0
190
70
100 140
4

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
5

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 AC”
model series thermostatic mixing valves include integral check valves in the hot and cold inlet ports.
NOTE TO INSTALLER: DO NOT TEST FIT OR INSTALL CHECK VALVES BEFORE SOLDERING. IF
INSTALLED, REMOVAL WILL REQUIRE DAMAGING THE CHECK VALVE AND IT WILL NO LONGER
BE USABLE.
The diagram below shows the order in which everything goes together. Note that the check valves
are installed on the hot and cold inlets, the mixed outlet does not require a check valve. Note that the
O-ring is installed on to the groove of the check valve.
After soldering the tailpieces into place, slide in the check valve into the tailpiece with o-ring going in
first. It will click into place and then the screen will fit into the groove of the tailpiece with the domed
end facing the mixing valve. Once the check valve and screen is installed, use the sealing washer
between the tailpiece and mixing valve body to create a seal and tighten down the union nut.
Commissioning
The special purpose of the thermostatic mixing valve must be commissioned in accordance with
current standards by qualified personnel using temperature measuring equipment. Caleffi codes
521419A, 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 final setting of the mixed water temperature.
NOTE: Gauge adapters with 2” diameter, 20-210ºF scale, code NA10328 (1/2” sweat), NA10056
(3/4” sweat) or NA10058 (1” sweat) can be separately purchased and field installed to the Caleffi
MixCal series 521 models sold without the integral gauge adapters.
After installation, the valve must be tested and commisioned in accordance 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 fluctuations
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.
41 3
1
4
6
2
3
VALVE BODY
UNION NUT, Quantity 3 per valve
UNION WASHER, Quantity 3 per valve
INLET PORT MALE TAILPIECE
WITH INTEGRAL CHECK VALVE
Quantity 2 per valve
INLET PORT CONIC FILTER,
Quantity 2 per valve
7OUTLET PORT TAILPIECE,
Quantity 1 per valve
5CHECK VALVE O-RING
2 3 6
6
7
4
25
5
(SWEAT TAILPIECE)
6

MIX
3
2
4
SUPPLY
HOTCOLD
MIX
BOILER
SUPPLY
MIX
3
2
4
MIX
3
2
4
Safety relief valve
Check valve
Isolation valve
Expansion vessel
Filter
Pump
*
*
*
*
*
*
WATER
HEATER
WATER
HEATER
CALEFFI
CALEFFI
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
Radiant panels heating system
MIX
3
2
4
SUPPLY
HOTCOLD
MIX
BOILER
SUPPLY
MIX
3
2
4
MIX
3
2
4
Safety relief valve
Check valve
Isolation valve
Expansion vessel
Filter
Pump
*
*
*
*
*
*
WATER
HEATER
WATER
HEATER
CALEFFI
CALEFFI
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
*MixCal series 521 thermostatic mixing valves with inlet check valves, “AC” models, can be used
instead of separately installed check valves.
MIX
3
2
4
SUPPLY
HOTCOLD
MIX
BOILER
SUPPLY
MIX
3
2
4
MIX
3
2
4
Safety relief valve
Check valve
Isolation valve
Expansion vessel
Filter
Pump
*
*
*
*
*
*
WATER
HEATER
WATER
HEATER
CALEFFI
CALEFFI
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
Domestic hot water system
without recirculation
Domestic hot water system
with recirculation
CALEFFI
3
2
4
COLD
HOT
HOT/RED COLD/BLUE
MIX
MIX
3
2
4
SUPPLY
HOTCOLD
MIX
BOILER
SUPPLY
MIX
3
2
4
MIX
3
2
4
Safety relief valve
Check valve
Isolation valve
Expansion vessel
Filter
Pump
*
*
*
*
*
*
WATER
HEATER
WATER
HEATER
CALEFFI
CALEFFI
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
CALEFFI
CALEFFI
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
10
0
8
6
4
2
Application Diagrams
Temperature adjustment
The temperature is set to the required value by means of the knob with a graduated scale, on the
top of the valve.
Pos. Min. 1 2 3 4 5 6 7 Max.
T (°F) 81 90 100 111 120 127 136 145 152
T (°C) 27 32 38 44 49 53 58 63 67
with: T
HOT = 155°F (68°C), with: T cold = 55°F (13°C), P = 43 psi (13 bar)
7

Replacement ttings
Complete kit Valve size Connection Union Nut Tailpiece Washer
NA20640
½ inch
NPT male
F61008
R31981
F50055
NA20640C 59893A
NA20649 Sweat NA10002
NA20649C 59904A
NA20646 Press incl. w/ tailpc NA16264
NA20647 PEX crimp F61008 F0000492
NA20647A NA10484
NA20650
¾ inch
NPT male
F61008
31901A
F50055
NA20650C 59840A
NA20659 Sweat NA10003
NA20659C 59905A
NA20656 Press incl. w/ tailpc NA16264
NA20656A F0000698 NA10419
NA20657 PEX crimp F61008 F0000520
NA20657A NA10485
NA20660
1 inch
NPT male
incl. w/ tailpc
59817A
F50055
NA20660C 59894A
NA20669 Sweat 59834A
NA20669C 59906A
NA20666 Press NA16266
NA20667 PEX crimp F61008 F0000521
NA20667A NA10486
Replacement parts
Replacement body.
Meets requirements of
NSF/ANSI 372-2011.
Certified to: ASSE
1017/CSA B125.3,
Low lead, by ICC-ES
file PMG-1360.
ASSE 1017
521101A.........................1" male union thread
Point of distribution
mixed temperature
gauge adaptor fits
MixCal™ 521 series
mixing valves. Threaded
union mounting
replaces existing mixed
outlet with ¾" or 1"
sweat pipe connection.
NA10328.........................½" sweat with gauge
NA10056.........................¾" sweat with gauge
NA10058..........................1" sweat with gauge
NA10358 ...............1" union thread with gauge
688003A...Replacement gauge w/ pocket well
R39591............................ Replacement gauge
Removable gauge fits into temperature well.
Gauge dial is 2” diameter and scale from
30—210º F.
8

Troubleshooting
Under normal operating conditions the Caleffi 521 thermostatic mixing valve will provide a very high
level of performance. However, in some circumstances, where the following maintenance schedule
is not followed problems may arise.
Recommended maintenance schedule:
Tests should be conducted regularly to monitor the thermostatic mixing valve performance, as
deterioration of performance could indicate that the valve and/or the system require maintenance. If,
during these tests, the temperature of the mixed water has changed significantly in comparison with
the previous test, the details given in the installation and commissioning sections should be checked
and maintenance conducted.
The following should be checked regularly to ensure that the optimum performance levels of the
valve are maintained. Check every 12 months at least, or more often if necessary.
1) Check and clean the system filters.
2) Check that any check valves positioned upstream of the Caleffi thermostatic mixing valve are
operating correctly, without problems caused by impuritites.
3) Limescale can be removed from internal components of the thermostatic mixing valve by
immersion in a suitable de-scaling fluid.
4) When the components which can be maintained have been checked, commission the valve.
9

10
Symptoms Cause Corrective action
Hot water at the cold taps a) Operation of check valve is
hindered; Check valve is not
sealing correctly.
b) Check valves not fitted.
- Replace faulty check valve
Fluctuating mixed water
temperature
a) Erratic supply temperatures at
the inlet of the valve.
b) Starvation of the water
supplies at the inlets of the valve.
c) Incorrect commissioning of the
valve.
- Restore inlet conditions within
the limits of the valve.
Erratic flow of water from
the valve
a) Insufficient water supplies
b) Fluctuations in the supply
pressures/temperatures.
c) Adverse effect created by other
draw off points on the system
- Stabilize inlet supply condi-
tions.
No flow of water from the
valve
a) In-line filers blocked.
b) Insufficient supply pressures.
c) Debris obstructing valve
operation.
- Clean filters
- Resore inlet supplies
- Clean debris or scale from
the valve.

11
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Caleffi North America, Inc.
3883 West Milwaukee Road
Milwaukee, WI 53208
T: 414.238.2360 F: 414.238.2366
12-1-17
12