Lochinvar SIT040, SIT050, SIT065, SIT080, SIT119 Installation Manual

100273038_2000529317 Rev A

Installation & Operation

Manual

Models: SIT040DW - SIT119DW

LOW LEAD CONTENT

 WARNING

Save this manual for future reference.

This manual must only be used by
a qualified heating installer / service
technician. Read all instructions
before installing. Perform steps in
the order given. Failure to comply
could result in severe personal
injury, death, or substantial property
damage.

Contents

HAZARD DEFINITIONS .................................................... 2

PLEASE READ BEFORE PROCEEDING ........................ 3

1. GENERAL INFORMATION

Operating Restrictions ........................................................ 4

Double-Wall Heat Exchanger ............................................. 4

2. PRE-INSTALLATION

Locating the Tank ............................................................... 5

Recommended Clearances ................................................ 5

3. BOILER SIDE PIPING

Zone with Circulator to Aquastat ........................................ 6

Zone with Valve to Aquastat .............................................. 6

DHW Prioritization .............................................................. 6

Multiple Tank Connections (Boiler Side) ............................ 6

Table 3A - Pressure Drop Chart ................................... 6

Table 3B - Pressure Drop Values ................................. 6

Piping Diagrams ............................................................ 7-10

4. DOMESTIC SIDE (TANK) PIPING

Basic Domestic Piping ................................................. 11

Multiple Tank Domestic Water Piping .......................... 11

Domestic Water Piping for Distant Fixtures ..................11

Hazard definitions

Anti-scald Valves (Mixing Valves) ............................. 12

Install Drain Valve ...................................................... 12

Temperature and Pressure (T&P) Relief Valve .......... 12

Table 4A - Minimum Relief Valve (AGA Rating) ... 13

5. WIRING

Indirect Water Heater Sensor Setup (Knight Boiler) ........ 14

Install and Connect Tank Sensor ............................... 14

Indirect Water Heater Controlled Using Aquastat and

Zone Circulator ................................................................. 15

6. START-UP AND CHECK-OUT .................................. 16

7. MAINTENANCE

Maintenance Schedule ..................................................... 17

To Fill the Water Heater ............................................. 17

To Drain the Water Heater ......................................... 17

8. PERFORMANCE DATA

AHRI Chart ....................................................................... 18

How to Properly Size Your Indirect Water Heater ........... 19

Performance Data Charts ........................................... 20-22

REVISION NOTES ............................................ Back Cover

The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels
or to important information concerning the life of the product.

 DANGER

 WARNING

 CAUTION

CAUTION

NOTICE

DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.

WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.

CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or
moderate injury.

CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.

NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.

2

Please read before proceeding

Installation & Operation Manual

 WARNING

NOTICE

 WARNING

Installer – Read all instructions before
installing. Perform steps in the order given.

Have this indirect water heater serviced/
inspected by a qualified service technician, at
least annually.

Failure to comply with the above could
result in severe personal injury, death or
substantial property damage.

When calling or writing about the appliance
– Please have the indirect water heater model
and serial number from the indirect water
heater rating plate.

Consider piping and installation when
determining appliance location.

Any claims for damage or shortage in
shipment must be filed immediately
against the transportation company by the
consignee.

Factory warranty (shipped with appliance)
does not apply to appliances improperly
installed or improperly operated.

If the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.

This appliance MUST NOT be installed in
any location where gasoline or flammable
vapors are likely to be present.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electric switch; do not
use any phone in your building.

• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.

• If you cannot reach your gas supplier, call
the fire department.

• Installation and service must be performed by a qualified
installer, service agency, or the gas supplier.

 WARNING

Failure to adhere to the guidelines on this
page can result in severe personal injury,
death, or substantial property damage.

When servicing the indirect water heater –

• To avoid severe burns, allow the appliance to cool
before performing maintenance.

Indirect water heater operation –

• Should overheating occur or gas supply fail to shut off,
do not turn off or disconnect electrical supply to
circulator. Instead, shut off the gas supply at a location
external to the appliance.

• Do not use this appliance if any part has been under
water. The possible damage to a flooded appliance can
be extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.

The following chart details the relationship of water temperature
and time with regard to scald injury and may be used as a
guide in determining the safest water temperature for your
applications.

APPROXIMATE TIME / TEMPERATURE

RELATIONSHIPS IN SCALDS

120°F More than 5 minutes
125°F 1 1/2 to 2 minutes
130°F About 30 seconds
135°F About 10 seconds
140°F Less than 5 seconds
145°F Less than 3 seconds
150°F About 1 1/2 seconds
155°F About 1 second

Hot Water Can Scald!

• Water heated to temperatures for clothes washing, dish washing, and other sanitizing needs can
scald and cause permanent injury.

• Children, elderly, and infirm or physically handicapped persons are more likely to be
permanently injured by hot water. Never leave them unattended in a bathtub or shower.
Never allow small children to use a hot water tap or draw their own bath.

• If anyone using hot water in the building fits the above description, or if state laws or local
codes require certain water temperatures at hot water taps, you must take special
precautions:

• Use lowest possible temperature setting.

• Install some type of tempering device, such as an automatic mixing
valve, at hot water tap or water heater. Automatic mixing valve must be selected and
installed according to valve manufacturer’s recommendations and instructions.

• Water passing out of drain valves may be extremely hot. To avoid injury:

• Make sure all connections are tight.

• Direct water flow away from any person.
Protection Must Be Taken Against Excessive Temperature and Pressure!

--Installation of a Temperature & Pressure (T&P) relief valve is required.

3

1 General information

Installation & Operation Manual

The Lochinvar SIT DW series indirect water heater (FIG. 1-1)
is designed to generate domestic hot water in conjunction
with a hot water boiler using forced boiler water circulation.
This indirect water heater consists of a 316L Stainless Steel
tank in which a smooth 316L stainless steel coil is located
(Table 1A). Boiler water is pumped through the coil and
heats the water in the tank. This tank is not intended for use
in pool heating applications or for heating any fluid other
than water. It is also not intended for use in gravity hot water
heating systems.

Operating restrictions:

• Maximum domestic hot water temperature is 194°F.

• Maximum boiler water temperature is 210°F.

• Maximum working pressure for the vessel tank is
150 psig.

Table 1A

Component Materials

Component Material

Tank 316L Stainless Steel

Coil 316L Stainless Steel

Double-wall heat exchanger

Uniform plumbing code

Heat exchangers used for heat transfer or heat recovery shall be
separated from the potable water by a double-wall construction
with a space open to the atmosphere between the two (2) walls.

Insulation Polyurethane

Jacket Polypropylene / ABS

Figure 1-1 Lochinvar SIT DW Series Indirect Water Heater

PAR T NO.

“F”

SIT040DW

SIT050DW

SIT065DW

SIT080DW

SIT119DW

NOTES:

22.5°

45°

1” FPT (SEE NOTE 1)

“E”

“D”

1. 1” FPT ON MODELS SIT040DW - 050DW

2. 1-1/2” MPT ON MODELS SIT065DW - 119DW

2

1

3/4” FPT

1” MPT

3

AQUASTAT/SENSOR WELL

“A”

(in.)

3 7/16

3 3/8

3 1/8

3 1/8

3 1/8

“B”

(in.)

8 7/8

9 1/4

9 1/4

9 1/2

9 1/2

“C”

(in.)

25 1/8

25 3/8

29 1/4

29 1/4

29 1/4

“D”

(in.)

30 7/8

39 3/8

53

61 1/2

59 7/8

1. RELIEF VALVE CONNECTION

2. HOT WATER OUTLET

3. BOILER WATER IN

4. BOILER WATER OUT

5. DRAIN/COLD WATER INLET

“E”

(in.)

38 1/8

48 3/8

59 3/8

68 7/8

67 5/8

WEIGHT

“F”

FULL OF WATER

(in.)

24

24

24

24

28

(lbs.)

463

581

775

900

1250

1” MPT

“C”

“B”

“A”

4

1” MPT (SEE NOTE 2)

5

SIT040DW - SIT119DW

4

2 Pre-installation

Installation & Operation Manual

1. The installation must conform to the instructions
in this manual and all applicable local, state,
provincial, and national codes, laws, regulations, and
ordinances. Installations in Canada must conform to
B149.2 Installation Code.

2. Be certain the domestic water supply to the tank has
physical and chemical characteristics that fall within
the limits shown in Table 2A. Where questions exist
as to the composition of the water on the job, a
qualified water treatment expert should be consulted.

CAUTION

3. Read and understand all installation requirements in
this manual.

Water with characteristics outside the
limits shown in Table 2A may severely
shorten the life of the tank due to
corrosion. Damage to tanks in such
cases is not covered under warranty.

Table 2A

Water Chemistry Requirements

Water used in the tank must have characteristics falling
within the following limits:

Characteristic Min. Max.

Ph 6.0 8.0

Locating the tank

1. Choose a location for your water heater centralized to the
piping system. You must also locate the SIT DW water heater
where it will not be exposed to freezing temperatures.
Additionally, you will need to place the water heater so that
the controls, drain, and inlet/outlets are easily accessible.
This appliance must not be installed outdoors, as it is
certified as an indoor appliance, and must also be kept
vertical on a level surface.

2. Keep distance between boiler and water heater to a
minimum to:
a. reduce piping heat loss
b. provide minimal friction loss

3. Figure 1-1 on page 4 shows the weights of all the tanks filled
with water. Make sure that the location chosen for the tank
is capable of supporting it.

CAUTION

This appliance must be placed where leakage
from the relief valve, leakage from the
related piping, or leakage from the tank or
connections, will not result in damage to the
surrounding areas, or to the lower floors of
the building. A water heater should always
be located in an area with a floor drain or
installed in a drain pan suitable for water
heaters. Lochinvar shall not be held liable for
any such water damage.

Chloride (PPM) -- 80

4. The tank may be located some distance from the boiler
provided the pump is designed to provide the flow
called for in Table 3B - Pressure Drop Values, through
the coil. Also, the further the tank is from the boiler, the
longer the response of the boiler will be to a call from the
tank zone. Insulate piping between the boiler and the tank.

 WARNING

Failure to properly support the tank could
result in property damage or personal injury.

Recommended clearances

The installation location must provide adequate clearances
for servicing and proper operation of the water heater. A 12
inch vertical clearance is recommended from the top of the
water heater. A zero clearance is allowed for the sides of the
water heater. However, boiler and servicing clearances must be
figured when locating the water heater.

5

3 Boiler side piping

0

5

10

15

20

25

0 5 10 15 20 25 30 35

Foot Of Head

Flow

Pressure Drop Coil

36.5

44

44'

36.5'

Installation & Operation Manual

Figures 3-1 thru 3-4 show typical boiler side piping for
several common situations. Regardless of which system is
used it is imperative that the flow rates called for in Table
3B are developed through the coil. This requires properly
sized piping and a properly sized pump.

The system shown in FIG’s 3-1 thru 3-4 are described
below:

Zone with circulator to Aquastat

This system is like the circulator zone system on a straight
heat job except that one of the zones goes to the tank
instead of radiation. As on any circulator zone system
check valves should be installed in each zone to prevent
unwanted circulation through zones which are not calling
for heat. Figure 3-1 on page 7 illustrates typical circulator
zone piping.

Zone with valve to Aquastat

As with the circulator zone system, this system is just like a
standard heating zone system except that one of the zones
is connected to the tank coil as shown in FIG. 3-2. The
system circulator must be large enough to move boiler
water through the coil regardless of the flow rate required
through the heating zones.

DHW prioritization

This piping system is designed to provide direct hot water
priority over the other zones in the heating system. When
there is a Domestic Hot Water (DHW) call for heat, the
Knight control will shut off the boiler circulator and activate
the domestic hot water circulator. Once the DHW demand
is satisfied, the boiler circulator will be readjusted as demand
requires. The circulator must be large enough to move the
boiler water through the coils. The recommended piping for a
DHW priority system is depicted in FIG. 3-3 on page 9.

Multiple tank connections (boiler side)

Multiple tank installations must be done in the “reverse-return”
manner. The reason for this is to create the same pressure drop
(and therefore, the same flow) through the coil of each tank.
The boiler manifold piping must be sized so that each coil has
the flow rate called for in Table 3B.

Because the pressure drop through tank coils varies from size
to size, it is hard to predict the flow rate that will be developed
through each coil when two tanks of different sizes are placed
in the same manifold. For this reason it is best not to mix tanks
of different sizes in the same zone if their recovery is critical.

WATER

MODEL

SIT040 1 1 1 36.5 12.05 0.87 1.99 4.05 6.00 9.89 14.62 20.11

SIT050 1 1 1 36.5 12.05 0.87 1.99 4.05 6.00 9.89 14.62 20.11

SIT065 1.5 1.5 1 44 15.03 0.94 2.14 4.35 7.20 10.64 15.72 21.63

SIT080 1.5 1.5 1 44 15.03 0.94 2.14 4.35 7.20 10.64 15.72 21.63

SIT119 1.5 1.5 1 44 15.03 0.94 2.14 4.35 7.20 10.64 15.72 21.63

INLET

NPT

6

WATER

OUTLET

NPT

Pressure Drop Coil Chart

COIL

CONNECTION

NPT

Table 3A

Table 3B

Pressure Drop Values

COIL

LENGTH

FT

SQ FT

SURFACE

AREA

GPM8 GPM

PRESSURE DROP

FT/HD

5

12

GPM16GPM

20

GPM25GPM

30

GPM

3 Boiler side piping (continued)

Figure 3-1 Piping Diagram Zoned with Circulators

ZONE #1

Installation & Operation Manual

MAKE UP WATER

DRAIN POINT

(TYPICAL)

BALL VALVE

(TYPICAL)

PRESSURE

REDUCING VALVE

BACKFLOW

PREVENTER

AIR SEPARATOR

EXPANSION

TANK

PRESSURE

GAUGE

SYSTEM SUPPLY

SENSOR

(WHEN USED)

NOT TO EXCEED 4 PIPE DIA.

OR A MAXIMUM OF 12" APART

Y-STRAINER

FLOW CHECK

BOILER
CIRCULATOR

VALVE

ZONE #2

HOT

WATER

OUT

ZONE #3

ANTI-SCALD
MIXING VALVE

ZONE #4

COLD

WATER

IN

ZONE CIRCULATORS

(TYPICAL)

NOTICE

NOTICE

RELIEF VALVE

TANK SENSOR/
AQUASTAT

UNION

(TYPICAL)

TEMPERATURE /

PRESSURE

GAUGE

RELIEF VALVE

DRAIN

PRESSURE

SOLUTION

BOILER

SQUIRE

DRAIN
( FIELD SUPPLY )

RECIRCULATION

CHECK VALVE

PUMP

Please note that these illustrations are meant to show system piping concept only, the installer is responsible
for all equipment and detailing required by local codes.

Please note that the installer is responsible for ensuring DHW prioritization when piped as a zone.

7

3 Boiler side piping

Figure 3-2 Piping Diagram Zoned with Valves

Installation & Operation Manual

ZONE #1

REDUCING VALVE

BACKFLOW

PREVENTER

DRAIN POINT

(TYPICAL)

BALL VALVE

(TYPICAL)

PRESSURE

MAKE UP WATER

AIR SEPARATOR

EXPANSION

TANK

PRESSURE

GAUGE

SYSTEM SUPPLY
SENSOR
(WHEN USED)

NOT TO EXCEED 4 PIPE DIA.

OR A MAXIMUM OF 12" APART

Y-STRAINER

BOILER
CIRCULATOR

CIRCULATOR

ZONE #2

ZONE #3

HOT

WATER

OUT

ZONE #4

ANTI-SCALD

MIXING VALVE

COLD

WATER

IN

ZONE VALVES

(TYPICAL)

DIFFERENTIAL
PRESSURE BYPASS
VALVE (IF USED)SYSTEM

TEMPERATURE /

PRESSURE

NOTICE

NOTICE

8

RELIEF VALVE

TANK SENSOR/
AQUASTAT

UNION

(TYPICAL)

GAUGE

DRAIN

PRESSURE

RELIEF VALVE

SOLUTION

BOILER

SQUIRE

DRAIN
( FIELD SUPPLY )

RECIRCULATION
PUMP

CHECK VALVE

Please note that these illustrations are meant to show system piping concept only, the installer is responsible
for all equipment and detailing required by local codes.

Please note that the installer is responsible for ensuring DHW prioritization when piped as a zone.