CALEFFI 523160A, 523168A, 523170A, 523178A, 523177A Installation, Commissioning And Service Instructions

Low Lead High Flow Thermostatic Mixing Valves

5231 Series

NA10341.02

www.caleffi.com

© Copyright 2015 Caleffi

ASSE 1017

Installation, commissioning and service instructions

Function

ASSE 1017 model 5231 series high flow thermostatic mixing valves are
designed to be installed at the hot water heater (point of distribution) and
cannot be used for tempering water temperature at fixtures as a point-of-use
valve. They are not designed to provide scald protection and should not
be used where ASSE 1070 devices are required. Series 5231 thermostatic
mixing valves can also be used for regulating the flow temperature in radiant
panel heating systems, to which it assures a constant and accurate control
with ease of installation.

Product range

5231 series thermostatic mixing valve. Union thread NPT male and
union sweat connections, sizes 1", 1 ¼", 1 ½", 2". Inlet port check valve
assemblies available separately for field installation.

Technical characteristics

Materials: - body: DZR low-lead brass

- shutter: brass

- springs: stainless steel

- seals: EPDM

- check valve extension (field installed): stainless steel

Suitable fluids: water
Max. percentage of glycol: 30% glycol solution
Setting range: see table on page 2
Temperature stability: ±3°F (±2°C)
Max. working pressure (static): 200 psi (14 bar)
Max. working 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)
Mixed temperature range: 95–150°F (32–66°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: 20°F (11°C)
Max. water hardness: 10 grains
Certified to:

1. cUPC listed to ASSE 1017/CSA B125.3 Reduction of Lead in
Drinking Water Act Compliant: 0.25% Max. weighted average
lead content. Certifed by IAPMO R&T.

2. Meets requirements of ANSI/NSF 372 - 2011.

Code Description Flow

523160A 1" Union Thread NPT male 4.4 Cv
523168A 1" Union Sweat 4.4 Cv
523170A 1 ¼" Union Thread NPT male 4.4 Cv
523178A 1 ¼" Union Sweat 4.4 Cv
52317 7A 1 ¼” Union Sweat with outlet temp. gauge 4.4 Cv
523179A 1”, 1 ¼” Replacement body 4.4 Cv
523180A 1 ½” Union Thread NPT male 8.8 Cv
523188A 1 ½” Union Sweat 8.8 Cv
523190A 2” Union Thread NPT male 8.8 Cv
523198A 2” Union Sweat 8.8 Cv
523199A 1 ½”, 2” Replacement body 8.8 Cv

Replacement fitting part numbers

Code Description

Tailpiece

all ports (3)

Inlet Check

Valve

Assembly (2)**

Union

nuts (3)

Gaskets

(3)

523160A

1" Union Thread NPT male

NA10009

NA10366

R31589 R50057

523168A 1" Union Sweat 31554 FD

52 317 0A 1 1/4" Union Thread NPT male R4166 0

52 317 8A 1 1/4" Union Sweat 4178 7 C S T

52 3177A 1 1/4” Union Sweat with outlet temp. gauge*

4178 7 C S T

(2 only)

R31589

(2 only -

177A )

R50057

(2 only -

177A )

523180A 1 1/2” Union Thread NPT male 41371A

NA1037 7 R518 3 8 R50060

523188A 1 1/2” Union Sweat 4178 8 CST

523190A 2” Union Thread NPT male 41372A

523198A 2” Union Sweat 41789 CST

* 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

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

HOT

= 155°F (68°C) · T

COLD

= 55°F (13°C) · P

INLETS

= 43 psi (3 bar)

Setting the temperature

The temperature is set to the required value by means of the adjustment knob with the graduated
scale on the top of the valve

Principle of Operation

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.

Thermal
Shutoff

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 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.

Recommended
flowrates for
temperature stability:

Flow curves

10

0.1

1

0.2

0.3

0.5

20

50

p (psi)

10

2

3

5

20

0.1

1

0.2

0.3

0.5

(psi) (bar)

10

2

3

5

20

10

2

5

2

0

0.01

0.1

0.02

0.03

0.05

1.0

0.2

0.3

0.5

4

0.4 0.4

4

0.04

0.4

50

10

0

100

200

1 ¼"

1 ½"

2"

4.4

8.84070

Min.

Max.

(gpm) (gpm)

10

0.1

1

0.2

0.3

0.5

20

50

∆p (psi)

G

(l/min) (

gpm

)

10

2

3

5

20

0.1

1

0.2

0.3

0.5

(psi) (bar)

10

2

3

5

20

10

2

5

2

0

0.01

0.1

0.02

0.03

0.05

1.0

0.2

0.3

0.5

4

0.4 0.4

4

0.04

0.4

50

10

0

100

200

G

(l/min) (

gpm

)

1” 523060A
523068A

1/2” - 3/4”

1”

224

Min.

Max.

(gpm) (gpm)

1" 7

7.6

13

14.2

Cv

1-1/4”

1-1/2”

2”

HOT

MIXED

COLD

.1

0.23

2.3

0.46

0.69

1.15

.3

1

∆p (ft of head)

G

(l/s) (

gpm

)

23

4.6

6.9

11.5

46

0.1

1

0.2

0.3

0.5

(psi) (bar)

10

2

3

5

20

10

2

5

20

0.01

0.1

0.02

0.03

0.05

1.0

0.2

0.3

0.5

9.2

0.92 0.4

4

0.04

0.4

50

100

1.5

3.25

1” 1 1/2” 2”

1 1/4”

 ∆p



50

160

6

10

2.0

5.0

115

172

75

Flow should never exceed standards for pipe size and material.

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.

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 SAFETY IS

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

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 mixing

valve connecting pipework 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: In the case of highly aggressive water, arrangements must be made
to treat the water before it enters the thermostatic mixing valve, in accordance
with current legislation. Otherwise the mixing valve may be damaged and will
not operate correctly.

Leave this manual for the user

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 model 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 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 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 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. 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 backflow. 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 port 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 pipework from/to the valve must not be used to support
the weight of the valve itself.

Application diagrams

T

Key to symbols

Safety relief valve

Check valve

Isolation valve

Expansion vessel

Filter

Pump

Domestic water system with recirculation

MI

N

M

A

X

7

1

2

1

2

Globe Valve

STORAGE

HOT WATER

HEATER

HOTCOLD

MIX

Radiant panel loop

MIN

M

A

X

7

1

2

RETURN

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

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

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.

Preset locking

Position the handle to the number required. 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.

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.

Replacement parts

Point of distribution mixed temperature
gauge adaptor fits High Flow 5231
series mixing valves. Threaded union
mounting replaces existing mixed
outlet with 1¼" sweat pipe connection.
Removable gauge fits into temperature
well. Gauge dial is 2" diameter and
scale from 30—210ºF.
Low-lead brass body.

Code Description Lbs

NA10315 1 ¼" sweat with gauge 0.5

688003A Replacement gauge 0.2

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' and 1 ¼" 0.23 psi 1.0

NA10367 Check valve assembly 1 ½" & 2" 0.20 psi 1.5

Replacement body.
Meets requirements of ANSI/NSF
372-2011.
Certified to: cUPC listed to ASSE
1017/CSA B125.3, Low lead.

ASSE 1017

5231

High Flow Body

Code Description Min. Flow (gpm) Cv Lbs

523179 A 1 ½" union thread 4.4 7.6 5.0
523199A 2 ½" union thread 8.8 14.2 15.0

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

Troubleshooting

Under normal operating conditions the Caleffi 5231 series thermostatic mixing valve will provide a
very high level of performance. 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

is hindered; check valve is
not sealing correctly

b) Check valves not fitted

•  Replace faulty check valves

Fluctuating mixer water
temperature

a) Erratic supply

temperatures at the inlets
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 supply

pressures/temperatures

c) Adverse effect created by

other draw off points on
the system

•  Stabilize inlet supply 

conditions

No flow of water from
thevalve

a) In-line filters blocked
b) Insufficient supply

pressures

c) Debris obstructing

valveoperation

•  Clean filters

•  Restore inlet supplies

•  Clean debris or scale 

fromvalve

04-30-15