Lochinvar SDT065 - 119, SET065 - 119 User Manual

Installation & Operation

Manual

Models: SDT/SET065 - 119

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.

 WARNING

Save this manual for future reference.

SDT-SET-I-O Rev B

SDT

Solar Dual Coil Tank

SET

Solar Electric Tank

Hazard definitions

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.

2

 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.

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

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

1. GENERAL INFORMATION

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

Single-Wall Heat Exchanger . . . . . . . . . . . . . . . . . . . . . . . 4

2. PRE-INSTALLATION

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

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

3. BOILER SIDE PIPING (SDT MODELS)

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

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

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

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

Table 3A - 3B - Pressure Drop Charts . . . . . . . . . . . . . 7

Table 3C - Pressure Drop Values . . . . . . . . . . . . . . . . . 7

Piping Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11

4. DOMESTIC SIDE (TANK) PIPING

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

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

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

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

Electrical Connection and Thermostat Setup . . . . . . . . . .16

Indirect Water Heater Sensor Setup (Knight Boiler) . . . . 18

Install Tank Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Indirect Water Heater Controlled Using Aquastat and Zone

Circulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6. START-UP AND CHECK-OUT . . . . . . . . . . . . . . . . . 20

7. MAINTENANCE

Maintenance Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . 21

To Fill the Water Heater . . . . . . . . . . . . . . . . . . . . . . . 21

To Drain the Water Heater . . . . . . . . . . . . . . . . . . . . . 21

8. PERFORMANCE DATA

Performance Data Charts . . . . . . . . . . . . . . . . . . . . . . . . 22-24

9. High Output Piping

High Domestic Hot Water Usage . . . . . . . . . . . . . . . . 25

Series Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25-26

Parallel Piping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25-27

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

Contents

SDT/SET Installation & Operation Manual

Please read before proceeding

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.

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.

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

NOTICE

 WARNING

 WARNING

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

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

1 General Information

The Lochinvar SDT/SET series indirect water heater
(FIG. 1-1) is designed to generate domestic hot water in
conjunction with a solar panel using forced circulation with a
backup heat source. This indirect water heater consists of a
316L Stainless Steel tank in which a smooth 304L stainless
steel coil is located (Table 1A). Solar heating fluid is pumped
through the coil and heats the water in the tank. If the solar
panel cannot produce enough heat, the backup source should
supply hot water. 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.

Table 1A

Component Materials

Component Material

Ta n k 316L Steel Stainless Steel

Coil 304L Stainless Steel

Insulation Polyurethane

Jacket ABS

Figure 1-1 Lochinvar SDT and SET Series Indirect Water Heaters

Single-Wall Heat Exchanger

National Standard Plumbing Code

Single-wall heat exchangers in water heaters comply with the
National Standard Plumbing Code provided that:

• boiler water (including additives) is practically non-toxic,
having a toxicity rating or class of 1, as listed in Clinical
Toxicology of Commercial Products, and

• boiler water pressure is limited to a maximum of 30 psig by
approved relief valve.

Uniform Plumbing Code

Single-wall heat exchangers are permitted if they satisfy all of
the following requirements --

1. The heat transfer medium is potable water or contains only
substances which are recognized as safe by the U.S. Food
and Drug Administration.

2. The pressure of the heat transfer medium is maintained less
than the normal minimum operating pressure of the
potable water system.

3. The equipment is permanently labeled to indicate that
only additives recognized as safe by the FDA shall be used
in the heat transfer medium.

Other heat exchanger designs may be permitted where
approved by the Administrative Authority.

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.

SDT/SET Installation & Operation Manual

4

“G”

“F”

SOLAR DUAL

COIL

“E”

“D”

“C”

1. RELIEF VALVE CONNECTION

2. HOT WATER OUTLET

3. BOILER WATER IN

4. BOILER WATER OUT

5. DRAIN / COLD WATER INLET

6. SOLAR WATER IN

7. SOLAR WATER OUT

8. ELEMENT

o

o

22.5

45

“B”

“A”

“I”

1 - 1/2” FPT

3/4” FPT

AQUASTAT WELL

1” MPT

SOLAR SENSOR

1” MPT

1 - 1/2” MPT

PAR T N O.

SDT065

SDT080
SDT119
SET065
SET090
SET119

1” MPT

1” MPT

“A”

(in.)
3 5/16
3 5/16
3 5/16
3 5/16

3 5/16
3 5/16

SOLAR ELECTRIC

2

1

3

8

6

“G”

7

5

“B”

(in.)
9 1/8
9 1/8
9 3/8
9 1/8
9 1/8
9 3/8

“F”

“C”

(in.)
27 15/16
27 15/16

31 11/16
27 15/16
27 15/16
31 11/16

“H”

WEIGHT

45

“H”

(in.)
N/A
N/A
N/A

59 7/8
59 7/8
59 7/8

o

“I”

FULL OF WATER

(in.)
24
24
28
24
24
28

“I”

1 - 1/2” FPT

3/4” FPT

1” MPSF

1” MPT

SOLAR SENSOR

1” MPT

1 - 1/2” MPT

(LBS)

820
921

1268

820
921

1268

2

1

8

6

7

5

“E”

“D”

(in.)

(in.)

33 5/8

47 3/16

53 3/4

40 3/16

54 1/2

37 7/16

N/A

N/A
N/A

N/A
N/A

N/A

“C”

“B”

“A”

“F”
(in.)

52 5/16

61 13/16

60 1/8

52 5/16

61 13/16

60 1/8

“G”

(in.)
59 7/8
69 3/8

68 3/16

59 7/8
69 3/8

68 3/16

22.5

o

5

2 Pre-installation

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.

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.

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

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

Chloride (PPM) -- 80

CAUTION

Locating the Tank

1. Choose a location for your water heater centralized to the
piping system. You must also locate the SDT/SET 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.

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.

CAUTION

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

 WARNING

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 (page 7)- Pressure Drop Values, through the
coil. 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.

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, electrical, and servicing clearances
must be figured when locating the water heater.

Minimum Clearance to the Element Cover

See FIG 2-1. Clearances must be a minimum of 24-inches to
allow for element removal and replacement on SET model.

SDT/SET Installation & Operation Manual

Figure 2-1 Element Cover Clearances

24” MIN CLEARANCE FROM

ELEMENT COVER

(SET Models)

6

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.

3 Boiler Side Piping (SDT models)

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 3C
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 8 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 on page

9. 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 coil in the tank, and it
must meet the minimum boiler flow requirments. The
recommended piping for a DHW priority system is
depicted in FIG. 3-3 on page 10.

SDT/SET Installation & Operation Manual

7

SDT/SET Installation & Operation Manual

Table 3A

Pressure Drop Chart SDT/SET065-080

Table 3C

Pressure Drop Values

MODEL

COIL

CONN.

(IN)

COIL

LENGTH

(FT)

SQ FT

SURFACE

AREA

PRESSURE DROP

SOLAR COIL

(FT / HD)

COIL

LENGTH

(FT)

SQ FT

SURFACE

AREA

PRESSURE DROP

BOILER COIL

(FT / HD)

5

GPM8 GPM

12

GPM16GPM20GPM

5

GPM8 GPM

12

GPM16GPM20GPM

SDT065

1 41.5 13.5 0.61 1.57 3.53 6.27 9.8 28 9.2 0.4 1.03 2.31 4.1 6.41

SDT080

1 41.5 13.5 0.61 1.57 3.53 6.27 9.8 28 9.2 0.4 1.03 2.31 4.1 6.41

SDT119

1 67.3 22.0 .73 1.87 4.22 7.5 11.71 48.5 16 0.61 1.57 3.53 6.27 9.8

SET065

1 41.5 13.5 0.61 1.57 3.53 6.27 9.8

SET080

1 41.5 13.5 0.61 1.57 3.53 6.27 9.8

SET119

1 67.3 22.0 .73 1.87 4.22 7.5 11.71

3 Boiler Side Piping (SDT models) (continued)

Table 3A Pressure Drop Chart SDT/SET065-080

Table 3C Pressure Drop Values SDT/SET065-119

Table 3B

Pressure Drop Chart SDT/SET119

Table 3B Pressure Drop Chart SDT/SET119

SDT / SET065 - 080 FRICTION LOSS

10.00

10.00

8.00

8.00

6.00

6.00

HDFT/

FT/HD

4.00

4.00

2.00

2.00

0.00

0.00

SDT / SET065 - 080 FRICTION LOSS

5 8 12 16 20

GPM

SOLAR

SOLAR

COIL

BOILER

BOILER

SDT

/

COIL

COIL

COIL

FT/HD

12.00

10.00

8.00

6.00

4.00

2.00

0

5 8 12 16 20

GPM

SET119 FRICTION

LOSS

SOLAR

COIL

BOILER

COIL

SDT/SET Installation & Operation Manual

8

Figure 3-1 Piping Diagram Zoned with Circulators

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.

NOTICE

3 Boiler Side Piping (SDT models)

NOTICE

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

ZONE #1

MAKE UP
WATER

DRAIN POINT

(TYPICAL)

BALL VALVE

(TYPICAL)

PRESSURE

REDUCING VALVE

BACKFLOW

PREVENTER

AIR SEPARATOR

EXPANSION

TANK

UNION

(TYPICAL)

TEMPERATURE /

PRESSURE

GAUGE

DRAIN

PRESSURE

RELIEF VALVE

GAS SUPPLY

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

BOILER BACKUP

HEAT EXCHANGER

( SDT MODELS ONLY )

SOLUTION

BOILER

SOLAR

HEAT EXCHANGER

ZONE#2ZONE

#3

HOT

WATER

OUT

SQUIRE

ZONE

#4

ZONE CIRCULATORS

(TYPICAL)

ANTI-SCALD
MIXING VALVE

COLD

WATER

IN

TEMPERATURE/

PRESSURE

RELIEF VALVE

BOILER

TANK SENSOR /

AQUASTAT

SOLAR SENSOR

CHECK VALVE

TEMPERATURE/
PRESSURE GAUGE
(TYPICAL)

RECIRCULATION

CHECK VALVE

DRAIN
( FIELD SUPPLY )

AUXILIARY CATCH PAN

FROM

SOLAR

TO

SOLAR

PUMP

Installation & Operation Manual

9

Figure 3-2 Piping Diagram Zoned with Valves

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.

NOTICE

3 Boiler Side Piping (SDT models) (continued)

NOTICE

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

ZONE #1

REDUCING VALVE

BACKFLOW

PREVENTER

MAKE UP
WATER

DRAIN POINT

(TYPICAL)

BALL VALVE

(TYPICAL)

PRESSURE

SYSTEM SUPPLY

AIR SEPARATOR

EXPANSION

(TYPICAL)

TEMPERATURE /

PRESSURE

GAUGE

SENSOR

(WHEN USED)

TANK

UNION

DRAIN

PRESSURE

RELIEF VALVE

GAS SUPPLY

PRESSURE

GAUGE

SYSTEM

CIRCULATOR

NOT TO EXCEED 4 PIPE DIA.

OR A MAXIMUM OF 12" APART

Y-STRAINER

BOILER
CIRCULATOR

BOILER BACKUP

HEAT EXCHANGER

( SDT MODELS ONLY )

SOLUTION

BOILER

SOLAR HEAT
EXCHANGER

ZONE

#2

SQUIRE

ZONE

#3

HOT

WATER

OUT

ZONE

#4

ZONE VALVES

(TYPICAL)

DIFFERENTIAL

PRESSURE

VALVE (IF USED)

ANTI-SCALD
MIXING VALVE

COLD

WATER

IN

TEMPERATURE/

PRESSURE

RELIEF VALVE

BOILER

TANK SENSOR /

AQUASTAT

SOLAR SENSOR

CHECK VALVE

TEMPERATURE/
PRESSURE GAUGE
(TYPICAL)

RECIRCULATION

CHECK VALVE

DRAIN
( FIELD SUPPLY )

AUXILIARY CATCH PAN

BYPASS

FROM

SOLAR

TO

SOLAR

PUMP