CALEFFI 5231 Series, 523168A, 523177A, 523170A, 523178A Installation And Commissioning Manual

NA10341.03

ASSE 1017

www.caleffi.com

Low lead high-flow thermostatic mixing valves

© Copyright 2018 Caleffi

5231 Series

INSTALLATION AND COMMISSIONING MANUAL

Function

The thermostatic mixing valve is used in systems producing domestic
hot water or in radiant heating systems. Its function is to maintain the
temperature of the mixed water supplied to the user at a constant set
value when there are variations in the supply pressure and temperature
of the incoming hot and cold water or in the flow rate.

The 5231 series thermostatic mixing valves are ASSE 1017 approved for
point of distribution and are designed specifically for systems requiring
high flow rates and precise, stable temperature control. Optional
stainless steel inlet port check valves are available separately, for field
installation only.

Product range

5231 series thermostatic mixing valve. NPT male and sweat union
connections, sizes 1", 1-1/4", 1-1/2", 2". Inlet port check valve s and
outlet temperature gauge optional.

Technical characteristics
Materials: - body: DZR low-lead brass (<0.25% lead content)

- shutter: PPSG40

- springs: stainless steel

- seals: peroxide-cured EPDM

- check valve extension (field installed): stainless steel

Suitable fluids: water, glycol solutions
Max. percentage of glycol: 30% glycol solution
Mixed temperature adjustment range: 95 – 150°F (32 – 66°C)
Temperature stability: ± 3°F (± 2°C)
Max. operating differential pressure (static): 200 psi (14 bar)
Max. operating differential pressure (dynamic): 75 psi (5 bar)
Hot water inlet temperature range: 120 – 195°F (49 – 91°C)
Cold water inlet temperature range: 39 – 80°F (3.9 – 26.6°C)
Max. inlet pressure ratio (H/C or C/H) for optimum performance: 2:1

Min. temp. difference between hot inlet and mixed outlet for optimum perf: 20°F (11°C)
Max. water hardness: 10 grains
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, certifed by ICC-ES, file PMG-1360.

1

SAFETY INSTRUCTION

This safety alert symbol will be used in this manual to draw attention to safety related instructions.
When used, the safety alert symbol means ATTENTION! BECOME ALERT! YOUR SAFET Y IS INVOLVED!

FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN A SAFETY HAZARD.

CAUTION: All work must be performed by qualified personnel trained in the
proper application, installation, and maintenance of systems in accordance
with all applicable codes and ordinances.

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

pipework connecting the thermostatic mixing valve is not mechanically
over-stressed. 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 100°F can be dangerous. During
the installation, commissioning and maintenance of the 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
thermostatic mixing valve.

Leave this manual for the user.

2

CONSIGNE DE SÉCURITÉ

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: Lorsque vous effectuez les raccordements d'eau, assurez-vous

que la tuyauterie reliant le 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.

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 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 le termostatico regolabile.

LAISSEZ CE MANUEL AVEC L’UTILISATEUR

3

Operating principle

A thermostatic mixing valve mixes hot and cold water in such a way as to maintain a constant set
temperature of the mixed water at the outlet.
A thermostatic element is fully immersed into the mixed water. It then contracts or expands causing
movement of the piston, closing either the hot or cold inlets, regulating the flow rates entering the
valve. If there are variations of temperature or pressure at the inlets, the internal element automatically
reacts attempting to restore the original temperature setting.

The Caleffi 5231 series mixing valves require a minimum temperature dif ferential from hot inlet
to mixed water outlet of 20°F (11°C) to ensure the correct operation, and maximum pressure
difference between the hot and cold inlet parts no greater than 2:1 ratio. Softened water use is highly
recommended as the warranty is voided if used on water with hardness greater than 10 grains.

Control

The Caleffi 5231 series
mixing valves require a
minimum temperature
differential from hot inlet to
mixed water outlet of 20°F
(11°C) to ensure the correct
operation, and maximum
pressure difference

COLD

HOT

between the hot and cold
inlet par ts no greater than
2:1 ratio. Softened water

without inlet check valves

use is highly recommended
as the warranty is voided
if used on water with
hardness greater than 10
grains.

COLD

with inlet check valves (field installed)

MIXED

HOT

Check valves field installed only: code NA10366 for 1” & 1¼”
sizes; code NA10367 for 1½” & 2” sizes.

4

Flow curves

6

100

 ∆p

(psi) (bar)

75

50

20

10

5
4

3

2

1

0.5

0.3

0.2

0.1

160

G

10

(l/s) (gpm)

5.0

2.0

1.0

0.5

0.4

0.3

0.2

0.1

0.05

0.04

0.03

0.02

0.01



∆p (ft of head)

172

115

46

23

11.5

9.2

6.9

4.6

2.3

1.15

0.92 0.4

0.69

0.46

0.23

2

.1

1” 1 1/2” 2”

5

.3

1 1/4”

10

20

1

50

1.5

3.25

Flow should never exceed standards for pipe size and material.

Size

Connection

Model

Min.
Flow*
(GPM)

Max.

Flow*

(GPM)

1" NPT 523160A 4.4 40 7

1" Sweat 523168A 4.4 40 7

1 ¼" NPT 523170A 4.4 40 7.6

1 ¼" Sweat w/

523177A 4.4 40 7.6

temp gauge

1¼" Sweat 523178A 4.4 40 7.6

1 ½" NPT 523180A 8.8 70 13

1 ½" Sweat 523188A 8.8 70 13

2" NPT 523190A 8.8 70 14.2

2" Sweat 523198A 8.8 70 14.2

*Recommended flow rates for temperature stabilty: ± 3°F (± 2°C).

CV

5

Use

Caleffi 5231 series thermostatic mixing valves are designed to be installed at the hot water
heater and cannot be used for tempering water temperature at fixtures as a point-of-use
valve. They are not designed to provide scald protection or chill protection service and
should not be used where ASSE 1070 devices are required. Wherever a scald protection
feature is required, ASSE 1070 certified mixing valves need to be installed. For safety
reasons, it is advisable to limit the maximum mixed water temperature to 120°F.

Instantaneous production of hot water

Caleffi 5231 series thermostatic mixing valves are designed for use on domestic water heaters that
have storage. The valve may deliver fluctuating mixed temperatures when used on instantaneous
domestic water heaters.

Installation

Before installing a Caleffi 5231 series thermostatic mixing valve, the system must be inspected to
ensure that its operating conditions are within the range of the mixing valve, checking, for example,
the supply temperature, supply pressure, etc.

Systems where the Caleffi 5231 series 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. Softened water use is highly recommended as the warranty is voided if used
on water with hardness greater than 10 grains.

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 5231 series thermostatic mixing valves must be installed in accordance with the diagrams
in this manual, taking into account all current applicable standards.

Caleffi 5231 series thermostatic mixing valves can be installed in any position, either vertical or
horizontal.

The following are shown on the mixing valve body:

- Hot water inlet, “H”.

- Cold water inlet, “C”.

- Mixed water outlet, unmarked.

In systems with thermostatic mixing valves, check valves must be installed to prevent undesirable
fluid back flow. The 5231 series valves, codes listed in this instruction sheet, do not contain integral
check valves, so those must be sourced separately. Caleffi offers inlet por t check valve assemblies
separately, for field installation only to 5231 series valve.

It is essential that access to the valve is totally unobstructed for any maintenance which may be
required to the valve or connections. The piping from/to the valve must not be used to support the
weight of the valve itself.

Scan to view

·

5231 MixCal

TM

Installation Tip

6

Locking the setting

Position the knob at the required value,
unscrew the top screw, slide off the knob and
put it back in such a way that the handle fits

3

1

M

I

2

N

M

A

X

into the internal slot of the knob. Tighten the
head screw

Setting the temperature

The temperature is set to the required value

.

Index
Point

by means of the adjusting knob with the
graduated scale on the top of the valve.

Pos. Min 1 2 3 4 5 6 7 Max

T (°F) 95 104 109 117 122 129 136 142 150
T (°C) 35 40 43 47 50 54 58 61 66

with: T

= 155°F (68°C) · T

HOT

= 55°F (13°C) · P

COLD

INLETS

= 43 psi (3 bar)

Dimensions

C

B B

A

F

A

D

HC

A

E

Sweat version

110

130

90

D

F

70

E

50

30

150

170

190

210

A

A

7

Code A B C D E F Wt (lb)

523160A 1" NPT 4" 8" 7 5/8" 4 3/16" 3 3/8" 7.0

523168A 1" SWT 3 5/16" 6 5/8" 7" 3 1/2" 3 3/8" 7.0

523170A 1 1/4" NPT 4 1/8" 8 1/4" 7 3/4" 4 5/16" 3 3/8" 7.0

523177A 1 1/4" SWT 3 3/8" 6 3/4" 7 5/8" 4 1/8" 3 3/8" 9.0

523178A 1 1/4" SWT 3 3/8" 6 3/4" 7" 3 1/2" 3 3/8" 7.0

523180A 1 1/2" NPT 5 1/8" 10 1/4" 9 3/16" 5 7/16" 3 3/4" 17

523188A 1 1/2" SWT 4 1/16" 8 1/8" 8 1/8" 4 3/8" 3 3/4" 17

523190A 2" NPT 5 1/8" 10 1/4" 9 1/2" 5 3/4" 3 3/4" 18

523198A 2" SWT 4 5/16" 8 5/8" 8 5/8" 4 7/8" 3 3/4" 18

7

Dimensions with check valves

C

B B

F

A

D

A

HC

Sweat version

A

E

A

110

130

150

90

D

F

170

70

E

190

50

30

210

A

Code A B C D E F Wt (lb)

1" NPT 5 1/2" 10 7/8" 7 5/8" 4 3/16" 3 3/8" 9.0

1" SWT 4 3/4" 9 1/2" 7" 3 1/2" 3 3/8" 9.0

NA10366

NA10367

Dimensions for 5231 models with field installed inlet check valve assembles, code
numbers listed in first column.

1 1/4" NPT 5 5/8" 11 1/8" 7 3/4" 4 5/16" 3 3/8" 9.0

1 1/4" SWT 4 3/4" 9 5/8" 7 5/8" 4 1/8" 3 3/8" 11.0

1 1/4" SWT 4 3/4" 9 5/8" 7" 3 1/2" 3 3/8" 9.0

1 1/2" NPT 7 3/8" 14 3/4" 9 3/16" 5 7/16" 3 3/4" 19

1 1/2" SWT 6 1/4" 12 5/8" 8 1/8" 4 3/8" 3 3/4" 19

2" NPT 7 3/8" 14 3/4" 9 1/2" 5 3/4" 3 3/4" 20

2" SWT 6 1/2" 13 1/8" 8 5/8" 4 7/8" 3 3/4" 20

8

Replacement ttings

Code

52316 0A

52316 8A 1" Sweat union 31554 FD

52 3170 A 1-1/4" MNPT union R416 60

52 3178 A 1-1/4" Sweat un ion 4178 7 C ST

52 317 7A

52318 0A 1-1/2” MNPT union 41371A

52318 8A 1-1/2” Sweat union 41788 CS T

52319 0A 2” MNPT union 41372 A

52319 8A 2” Sweat union F0000496

Description

1" MNPT union

1-1/4” Sweat union

with outlet temp. gauge*

Tailpiece

all por ts (3)

NA10009

4178 7 C ST

(2 only)

Inlet Check

Valve

Assemb ly (2)**

NA1 03 66

NA1 03 67 NA10 461 R518 38 R50060

* Replacement outlet mixed temperature gauge adapter complete with outlet tailpiece, union nut and gasket, and

temperature gauge (30-210°F), code NA10315.

**Field installed only

Outlet

adapter with

Temperature

Gauge**

NA1 0476 R31589 R 50057

Union

nuts ( 3)

R31589

(2 only

- 17 7A)

Gaskets

R500 57

(2 only -

177A )

(3)

Replacement parts

Point of distribution mixed
temperature gauge adaptor fits
high flow 5231 series mixing
valves. Removable gauge fits into
temperature well.
Gauge dial is 2" diameter and
scale from 30—210º F.
Low-lead brass body.

Code Description Lbs

NA10315 1¼" sweat with gauge 0.5

NA10476 For 1” & 1 ¼” * 3.0

NA10476 For 1 ½” & 2” * 4.0

688003A Replacement gauge with pocket well 0.2

R39591 Replacement temperature gauge 0.2

* Requires separately ordered union nut, tailpiece and
union washer. See replacement fittings table above.

Inlet check valve assembly for
mounting on inlet union tail pieces
of 5231 mixing valves. Stainless
steel body, acetal plastic check
valve insert with NBR o-ring.

Code Description Open Pressure Lbs

NA10366 Check valve assembly 1” & 1¼" 0.23 psi 1 .0
NA10367 Check valve assembly 1½" & 2" 0.20 psi 1.5

5231

Replacement body.
Meets requirements of
ANSI/NSF 372-2011.

ASSE 1017

Code Description Min. Flow (gpm) Cv Lbs

523179 A 1½" union thread 4.4 7.6 5. 0
523199A 2½" union thread 8.8 14.2 15.0

Includes no fittings or union nuts.

Certified to: ICC-ES listed to
ASSE 1017/CSA B125.3,
Low lead.

9

Commissioning

After installation, the valve must be tested and commissioned in accordance with the instructions
given below, taking into account current applicable standards.

1) Ensure that the system is clean and free from any dirt or debris before commissioning the
thermostatic mixing valve. Be sure water hardness is less than 10 grains.

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 at the outlet.

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 stabilized 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 120°F in domestic hot water systems.

Maintenance

Service tests should be carried out regularly to monitor the 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 carried out.

The following aspects should be checked regularly to ensure that the optimum performance levels
of the valve are maintained. Every 12 months at least, or more often if necessary.

1) Check and clean the system filters.

2) Check that any non-return valves positioned upstream of the Caleffi valve are operating correctly,
without problems caused by impurities.

3) Limescale can be removed from internal components by immersion in a suitable de-scaling
fluid.

4) When the components which can be maintained have been checked, commissioning should
be carried out again.

10

Application diagrams

Radiant panels heating system application

HOTCOLD

MIX

MIN

M

A

X

7

1

2

COLD

BLUE

HOT
RED

MIX

MIN

M

A

X

712

SUPPLY

C

A

LE

F

F

I

CA

L

E

FF

I

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

SUPPLY

HOTCOLD

7
X
A
M

MIN

1

2

10

10

10

10

10

10

8

8

8

8

8

8

6

6

6

6

6

6

4

4

4

4

4

4

2

2

2

2

2

2

0

0

0

0

0

0

CALEFFI

CALEFFI

I

I
F
F

FF
E

LE

L

A

CA

C

CALEFFI

CALEFFI

MIX

Key to symbols

Safety relief valve

Check valve

Isolation valve

Expansion vessel

Filter

Pump

Globe Valve

RETURN

Domestic water system with recirculation connected to tank

7
X
A
M

N
MI

1

2

T

STORAGE

HOT WATER

HEATER

Domestic water system without recirculation connected to tank

Radiant panel loop

7
X
A
M

N
MI

1

2

T

STORAGE

HOT WATER

HEATER

11

Troubleshooting

Under normal operating conditions the Caleffi 5231 series thermostatic mixing valve will provide a
very high level of per formance. However, in some circumstances, where our maintenance plan is not
followed, the following problems may arise.

Symptom Cause Corrective action

Hot water at the cold taps a) Operation of check valve

•  Replace faulty check valves

is hindered; check valve is
not sealing correctly

b) Check valves not fitted

Fluctuating mixer water
temperature

a) Erratic supply

temperatures at the inlets

•  Restore inlet conditions 

within the limits of the valve

of the valve

b) Starvation of the water

supplies at the inlets of
thevalve

c) Incorrect commissioning

ofthe valve

Erratic flow of water from
thevalve

a) Insufficient water supplies
b) Fluctuations in supply

•  Stabilize inlet supply 

conditions

pressures/temperatures

c) Adverse effect created by

other draw off points on
the system

No flow of water from
thevalve

a) In-line filters blocked
b) Insufficient supply

pressures

c) Debris obstructing

•  Clean filters

•  Restore inlet supplies

•  Clean debris or scale 

fromvalve

valveoperation

12

Caleffi North America, Inc.
3883 West Milwaukee Road
Milwaukee, WI 53208
T: 414.238.2360 F: 414.238.2366

01-19-18