Navien KDB-535GTD User manual

Medium-sized gas boiler
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1. Precautions for safety--------------------------------------30
2. Outside drawing of the boiler ----------------------------31
3. Safe and correct installation method --------------------34
4. Electric wiring installation --------------------------------37
5. Gas piping installation-------------------------------------39
6. Heating and hot water piping installation --------------41
7. Exhaust / Intake vent installation ------------------------47
8. Temperature controller installation ----------------------52
9. Check points for test operation---------------------------53
10. Electric wiring diagram ---------------------------------55
11. Specifications------------------------------------------------56
※ This installation manual is subject to change without notice for quality improvement.
Table of contents

Medium-sized gas boiler
30
Precautions for safety
The instructions provided in this installation manual include important
information for safe use of this product. Failure of complying with
those instructions may result in death, severe injury, or tremendous loss
of property.
The instructions for safe use are classified into ‘Danger’, ‘Warning’,
‘Caution’by the degree of danger, which respectively contains the
following meaning.
Violation of instructions may cause a seriously dangerous
situation such as death or a severe injury
Violation of instructions may cause a potentially dangerous
situation such as death or severe injury.
Violation of instructions may cause a potentially dangerous
situation such as a light or half-serious injury.
Violation of instructions may cause a situation such as a
property loss, product malfunction, or deteriorated performance.
1) The symbols provided in the product and the installation manual contains the
following meaning.
This symbol implies that “precautions” shall be taken against a possibility of a
personal injury under a specific condition.
This symbol implies that a “prohibition” shall be made against a possibility
of a personal injury or a property loss under a specific condition.
This symbol implies that the instructions shall be complied with.
2) The warnings and cautions specified in the installation manual do not include all
the possible safety precautions to be taken for using the product. Consequently,
utmost care shall be taken for safety during use of the product.
1

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Outside drawing of the boiler
 Model no.: KDB-535GTD, GTS, GTG
※ The sizes in the blank “( )” are applied to the model no..
※ A dedicated boiler (GTS, GTG) is not supplied with the hot water inlet and outlet on the rear of
the boiler.
 Model no.: KDB-535GPD, GPS
※ The sizes in the blank “( )” are applied to the model no.
※ A dedicated boiler (GPS) is not supplied with the hot water inlet and outlet on the rear of the
boiler.
2

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 Model no.: KDB-735GTD, GTS, GTG
※ The sizes in the blank “( )” are applied to the model no..
※ A dedicated boiler (GTS, GTG) is not supplied with the hot water inlet and outlet on the rear of
the boiler.
 Model no.: KDB-735GPD, GPS
※ The sizes in the blank “( )” are applied to the model no.
※ A dedicated boiler (GPS) is not supplied with the hot water inlet and outlet on the rear of the
boiler.

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 Model no.: KDB-1035GPD, GPS, GPG
1535GPD, GPS, GPG
2035GPD, GPS, GPG
※ The sizes in the blank “( )” are applied to the model no. 1535, and those in the bracket “[ ]” are to the
model no. 2035GPD, GPS, GPG.
※ A dedicated boiler (GPS, GPG) is not supplied with the hot water inlet and outlet on the rear of the
boiler.

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Safe and correct installation method
After completion of installation, be sure to return the user’s (installation) manual to the user.
Be sure to check the gas to be used in the
installation place, prior to installation.
 Use of the gas, other than the one specified on the
name plate on the front of the boiler, may result
in a fire or explosion.
Be sure to check the power supply gas to be
used in the installation place, prior to
installation.
 The power supply, if higher or lower than the one
specified on the front of the boiler, may cause a fire.
After reading the following instructions, install the product in a safe and correct way as
specified in the instructions.
Never install the boiler in a place with
inflammable objects.
 Highly inflammable materials, such as volatile
oil or alcohol, may cause a fire during ignition of
the boiler.
Install the boiler in a boiler room free froml
the impact of rain and wind.
 Incomplete combustions, resulting from rain and
wind, may eventually lead to a carbon oxide
poisoning.
3
Before installation
Selection of the installation place

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Never install the boiler in a moist or enclosed
place such as a bathroom, a toilet.
 Incomplete combustion, caused by oxygen
deficiency, may lead to a carbon oxide poisoning.
 Installation in the above place may also cause
earlier product malfunctions.
Never install the product with corrosive gas
such as ammonia, chlorine, sulfur, acids.
 Corrosive gas may damage the boiler and cause
incomplete combustion, eventually leading to a
carbon oxide poisoning.
Never install the boiler in the following areas.
Do not install the boiler near the electric equipment.
Do not install the boiler in an uneven or unstable place.
Do not install the boiler in a place with highly combustible materials.
Do not install the boiler in a place inadequate for safe gas piping installation.
Do not install the boiler in a place with special chemical agents
(generating combustible or corrosive gas).
Do not install the boiler in a place where it is difficult to get access to the
stairway or the exit for escaping.
Do not install the boiler in a place which is not well drained.
Do not install the boiler below the shelf with unstable objects.
Do not install the boiler in a place where it is difficult to conduct
maintenance of the boiler after installation.
Do not install the boiler in a place with noise and air pollution.
Do not install the boiler in a place where the wind generated from a vent, a
range, and a hood have an impact on the air intake and exhaust.
Do not install the boiler in a place which is not well-ventilated.
Do not install the boiler in a place with strong wind.
Do not install the boiler in a place where it is difficult to install the
chimney pipe (chimney).
Be sure to install the boiler in a sufficient place for check up and repair of
the boiler.
A space of more than 1m shall be provided in front of the boiler, in order to
perform maintenance and checks.
Other considerations

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 Install the boiler on the surface with a structure capable of enduring the load of the boiler (weight). (Refer to the
specifications presented in the user’s manual.)
 Install the boiler in a horizontal, upright position so that the boiler does not lean toward one side.
 Installation shall be made for the front side of the boiler to face forward.
 Install the boiler to be fixed on the floor, in order to prevent vibration during operation.
 Sufficient light shall be provided with the boiler room in order to help to observe the boiler equipment by sight
and offer the after-sales service for the equipment.
 Be sure to install the boiler in the dedicated boiler room. (The boiler room shall be designed so that the gas
emitted from the boiler does not flow into the living room, and the wall between the boiler room and the
living room shall be made of the fireproof materials, except for the entrance / exit door.)
 The dedicated boiler room shall not be equipped with the ventilating fan which causes the negative pressure (the
pressure lower than the atmosphere pressure).
 The dedicated boiler room shall not be equipped with the exhaust duct of the gas range (hood) which leads to air
flowing in and out of the living room and the kitchen.
 Installation of the boiler shall not be made nearby the place for storage and treatment of the combustible or
inflammable objects. A sufficient space shall be provided for boiler installation as presented in the following
figure, in order to perform the control, combustion, check-ups and repair of the boiler.
 The top of the boiler body shall be kept at least 1.2m away from the structures such as the ceiling and the piping.
 The boiler body shall be kept at least 450mm away from other structures such as the wall and the piping on the side of the
boiler.
 The front of the boiler shall be kept more than 1m away from the structures in front of the wall.
The boiler shall be kept away from the nearby combustible objects, as illustrated in
the following figure.
 Appropriate facilities such as the casing shall be equipped with the boiler to prevent the rain from permeating into
the boiler.
 The waterproof treatment shall be applied to the exposed insulation materials or lagging.
 Proper measures shall be taken to protect the water pipe outside the boiler from getting frozen.
 Proper measures shall be taken for boiler combustion to be protected against snow, rain and wind.
Precautions for boiler installation in a dedicated boiler room
Boiler installation method
Precautions for installation of the boiler in the outdoors

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Electric wiring installation
The electric wiring installation shall be
performed to comply with the power supply of
the product.
 The power supply, if higher or lower than the one
specified on the name plate on the front of the
boiler, may cause a fire.
Do not connect the power supply to the boiler until the
electric wiring installation is completed.
 With the power supply on, the electricity flowing through the
boiler may cause an electric shock.
Install the power outlet in a place free from the
impact of rain and moisture.
 Electric leakage, possibly resulting from rain and
moisture, may cause a fire.
4

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Never make a ground connection to the lightning
rods and the gas pipe.
 Ground connection to the lightning rod may result in a boiler
malfunction.
 Ground connection to the gas pipe may result in an explosive
accident.
Be sure to use the magnet switch for connection of the
circulation pump with more than 1.5kW.
 The boiler may malfunction, without the magnet switch.
 Install the electric wiring as presented in the electric wiring drawing in the installation manual.
 Install the dedicated power outlet for the boiler, with a length of less than the effective length of
the power cord. Installation shall be made for the power outlet not to get in contact with the drain
valve of the boiler.
 Use the power outlet with a cover attached, and install the outlet at more than 300m above
ground level.
 If the power outlet is not provided with a cover, install the outlet in a place free from the impact
of rain or moisture, or in the waterproof box or the indoor distribution box.
 Never install a switch onto the power cord, nor use the power outlet with a switch attached. (The
boiler does not operate, when the switch is set at off.)
 A ground connection shall be installed, if not, on the side of the power outlet.
 The wires of the room temperature controller shall be connected through the insulation pipe with
a thickness of more than 4mm. The insulation pipe shall be installed and concealed with an
upper gradient toward the indoors.
The wires of the circulation pump, connected to the controller, shall not be
short-circuited.
Correct electric wiring installation

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Gas piping installation
Be sure to perform the gas leak test after gas pipe
installation, replacement of the burner, or the
supply pressure or head pressure test.
 Retention of the leaked gas, combined with static electricity or
spark, may cause a fire
In preparaion for the unexpected gas leak, be sure
to install the gas leak alarm device and the gas
breaker in the boiler room.
 Retention of the leaked gas, combined with static electricity
or spark, may cause a fire
Be sure to check the gas to be used for the product
prior to gas piping installation.
 Use of the gas, other than the one specified on the name plate
on the front of the boiler, may cause incomplete combustion,
eventually leading to a fire or explosive ignition.
Install the gas holder, if used, in the well-ventilated
outdoor without above ground high voltage power
line. The gas holder shall be fixed not to fall down
on the ground.
 If the gas holder falls down or gets in contact with the high
voltage power line, an explosive accident may occur.
5

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The gas piping installation shall be performed by the gas
company and the gas piping installation company.
1 Refer to the “Specifications” presented in this installation
manual, with regard to the connection size.
2 Use the metal pipe or the metal flexible pipe which
passed a gas appliance test for gas piping. When LP gas
is used, never install the fuse cock, and be sure to install
the gas middle valve. (Installation of the fuse cock may
cause a boiler malfunction.)
3 The following shall be kept in mind, when using LP gas.
 The domestic low pressure regulator, appropriate for the
indicated gas consumption, shall be used as the LP gas
regulator.
 2 or more vessels with a weight of 50kg shall be installed
to be used for the LP gas vessel. (Connect the twin valve
to simultaneously supply the gas from 2 vessels.)
※ The vessels with a small capacity may result in gas loss
for lack of vaporization volume, which may cause a
boiler malfunction.
4 Be sure to connect the gas pipe directly to the main
pipe. Never connect the gas pipe in common with
other gas appliances.
5 A separable union connection or a nut connection
shall be made on the connection points.
6 The gas pipe shall be installed with its surface
exposed to the outside. However, the copper pipe, the
stainless steel pipe, or other pipes made of heat- and
corrosion-resistant materials without connection
joints (except for welding joints) may be buried for
installation.
7 Be sure to install the gas leak alarm device and the
gas breaker in the boiler room.
 LP gas: lower than the boiler
(300mm above the ground level)
 LNG : higher than the boiler

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The piping materials shall comply with the Korea Standard.
Gas pipe Carbon steel pipe for fuel gas piping, Copper or copper alloy pipe,
Metal flexible pipe which passed the gas appliance test
Heating pipe Copper or copper alloy pipe＋Insulation, XLPE pipe＋Insulation
Hot water
pipe Copper or copper alloy pipe＋Insulation, XLPE pipe＋Insulation
Items Distance from the gas pipe
Flue pipe & chimney 300mm or more
Electric switch, Power outlet 300mm or more
Electricity meter, Safety cutout 600mm or more
Wire 150mm
Size of the pipe Interval
13mm or less To fix every 1m
13mm~33mm To fix every 2m
33mm or more To every 3m
Piping materials
Piping installation
Fixing the pipe

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Heating and hot water piping installation
The exposed pipes shall be heat insulated with the
insulation material.
 The exposes pipes may get frozen in the winter.
 If the water supply pipe is frozen, the hot water is not
supplied. When the heating pipe has run out of water, the
water is not supplemented. Consequently, the boiler can
not operate normally.
Fix the parts of the boiler pipes with appropriate tools,
prior to piping installation.
 Do not exert excessive force on the pipe during the
installation, Damages on the parts may cause a water leak.
Be sure to use the insulation flange on the heating
inlet and outlet in case of installation of the copper
pipe (the hot water inlet and outlet for a boiler
dedicated for hot water supply).
 Failure to use the insulation flange may cause rapid
corrosion (rusty water).
 We do not take the responsibility of the problems arising from
failure to use the insulation flange.
Do not use water, other than the tap water, for the
boiler.
 Salt content in the sea water or spa water may accelerate
corrosion and shorten the life of the boiler.
 We do not take the responsibility of the problems caused by
using water, other than the tap water.
Install the pipes as illustrated in the standard pipe
drawing.
 Failure to install the pipe as illustrated in the standard
piping drawing may deteriorate the efficiency of the
boiler and the circulation of the heating water, which
may result in a boiler malfunction.
6

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 A separable union connection or a nut connection shall be performed on the connection points.
 The piping materials shall comply with the Korea Standard.
 Do not use the metals with different electric potentials to install the piping in the
dedicated boiler for hot water supply, (For example, do not install the copper pipe in the
iron boiler.) which may cause galvanic corrosion, eventually generating rusty water.
Do
not use the rubber hose for the faucet, when installing the piping.
Be
sure to remove foreign objects inside the pipe prior to the piping installation.
Install the piping correctly for the water supply, the hot water supply, the heating, and
the drain.
The
heating pipe shall be equipped with the heating strainer.
If the
water supply pressure exceeds the allowable working pressure specified on the
name plate, be sure to install the depressurizing valve.
Proper measures shall be taken against a water leak through a water leak test for the
entire piping after completion of installation.
The entire pipelines, except for the gas pipe, shall be provided with heat insulation to
protect against getting frost, after completion of installation. (Especially, care shall
be taken for the water supply and the hot water pipes.)
Be sure to install the pressure release pipe for installation of the boiler. If it is
impossible to install the pressure release pipe, the safety valve, operating below the
maximum allowable working pressure of the boiler, shall be installed.
(The maximum allowable working pressure of the boiler is presented in the
“Specifications”.)
Never install the valve and the check valve in the pipeline where the pressure release
pipe or the safety valve is installed.
Select the boiler expansion tank, if necessary, with a capacity suitable for the boiler
in use.
Do not use the water inlet for the purpose of the drain, and vice versa.
If the water is supplied to the boiler from the rooftop water tank, be sure to install the
water supply pipe in the auxiliary tank, separate from the rooftop water tank, for
water supply to the boiler.
Install the pipes as illustrated in the standard pipe drawing.
Precautions for piping installation
Considerations in common

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Model no. : KDB-535, 735 GTD, GTS
KDB-535, 735, 1035, 1535, 2035 GPD, GPS
Open piping system
- Be sure to comply with the instructions presented in the “Considerations in common”.
- Be sure to install the air vent valve in the distributor.
- The return water distributor shall be installed below the heating inlet on the boiler.
- The pressure release pipe shall be installed to exceed 25A.
- Never supply the water with a pressure higher than the maximum allowable working
pressure of the boiler specified on the name plate, nor connect the water pipe directly
for the piping.
- The reverse flow of the heating water into the expansion tank, while operating or
stopping the circulation pump, results from too much air in the pipe. (Open the valve in
the distributor one by one and remove the air from the pipe, while operating the
circulation pump.)
- The expansion tank shall be installed at least 1.5m above the heat dissipation surface in
case of the upward type, and at least 1.5m above the top of the boiler in case of the
downward type.
- The piping installation shall be performed not to mix the heating water and the hot
water.
Closed piping system
- Be sure to comply with the instructions presented in the “Considerations in common”.
- Be sure to install the strainer, the depressurizing valve, the check valve, and the closed
expansion tank, in order to directly connect the boiler to the water pipe.
- Be sure to install the depressurizing valve and the check valve in the water supply pipe.
- Install the air vent on top of the heat dissipation surface to facilitate air vent.
- Be sure to install the strainer in the water supply pipe, in order to prevent metal and
foreign objects from flowing into the water supply pipe.
- Be sure to install the safety valve.
- Be sure to install the closed expansion tank with an appropriate capacity.
Precautions for the piping installation for the combi boiler for
heating and hot water supply / the dedicated boiler for heating

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Composition
1. Body
2. Cap
3. Cap gasket
4. Strainer screen
Features: The device is to remove foreign objects in the boiler and the heating pipeline.
1. Prevention of corrosion in the pipe: The portion of accumulated foreign objects inside the pipe
gets corroded first. Accordingly, the foreign objects shall be strained to prevent corrosion.
2. Extension of the boiler life: The accumulated foreign objects obstruct heat transfer, and the
accumulated portion is overheated, which shortens the life of the boiler. Consequently, the
foreign objects shall be strained to extend the boiler life.
3. Protection of main equipment: The heating circulation pump, the valve, and other equipment
are protected from being damaged by foreign objects.
Installation method
1. Install the strainer in the direction of the heating water flow, as indicated in the body of the
heating strainer.
2. You may install the strainer in a horizontal or vertical direction, as desired.
3. Install the valves on each end of the heating strainer, in order to prevent the heating water
from draining during cleaning of the strainer.
4. The pocket shall be installed to face the ground surface, and a sufficient space shall be
provided for cleaning the strainer.
The method of cleaning (Removal of foreign objects)
1. Close the valves on each side of the strainer, to
completely shut off the heating water.
2. Open the cap to remove the foreign objects on the
strainer screen.(! Caution: Care shall be taken against
a burn, possibly caused by the heating water.)
3. After cleaning, check if there is a leak of the heating
water. Then, open the valve to use the strainer.
4. The heating strainer shall be cleaned periodically. At
the beginning of use, foreign objects usually remain
in the pipe, which shall be cleaned out.
STRAINER

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Model no.: KDB-535, 735 GTG
KDB-1035, 1535, 2035 GPG
Open piping system
- Be sure to comply with the instructions presented in the “Considerations in common”.
- Never supply the water with a pressure higher than the maximum allowable working
pressure of the boiler specified on the name plate, nor connect the water pipe directly
for the piping.
- Be sure to use the coated piping material and the stainless piping material for the
dedicated boiler for hot water supply.
- The pressure release pipe shall be installed to exceed 25A.
- The expansion tank shall be installed at least 1.5m above the maximum height of the
hot water pipe in case of the upward type, and at least 1.5m above the top of the boiler
in case of the downward type.
- When installing the hot water storage tank, connect the hot water outlet to lower part (inlet)
of the hot water tank, and the hot water inlet to the upper part (outlet) of the hot water tank.
- Use the connection wire to the circulation pump of the boiler to install the hot water
storage tank separately.
- If the water pressure is too low, attach an additional pump to the hot water outlet.
- When attaching an additional pump, be sure to install the pressure switch (S/W) and the
check valve. (Do not connect them to the wire of the circulation pump of the boiler.)
Closed piping system
-“Be sure to comply with the instructions presented in the “Considerations in common”.
-Be sure to install the strainer, the depressurizing valve, the check valve, the safety valve,
and the closed expansion tank, in order to directly connect the boiler to the water pipe.
-Be sure to use the coated piping material and the stainless piping material for the dedicated
boiler for hot water supply.
-Be sure to install the depressurizing valve and the check valve in the water supply pipe.
-Install the air vent on top of the hot water supply pipe to facilitate air vent.
-Be sure to install the safety valve.
-Be sure to install the closed expansion tank with an appropriate capacity.
-When installing the hot water storage tank, connect the hot water outlet to lower part (inlet)
of the hot water tank, and the hot water inlet to the upper part (outlet) of the hot water tank.
-Use the connection wire to the circulation pump of the boiler, in order to install the hot
water storage tank separately.
-If the water pressure is too low, attach an additional pump to the hot water outlet.
-When attaching an additional pump, be sure to install the pressure switch (S/W) and the
check valve. (Do not connect them to the wire of the circulation pump of the boiler.)
Precautions for the piping installation for the
dedicated boiler for hot water supply

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Exhaust / Intake vent installation
Installation of the exhaust and intake chimney
pipe (chimney) shall be performed in a specified
method.
 Incorrect installation of the exhaust and intake
chimney pipe (chimney) may lead to an exhaust
gas poisoning.
The connection points of the exhaust and intake
pipes shall be free from any leakage.
 The exhaust gas, if flowing into the indoors, may
cause carbon oxide poisoning.
The air intake or the exhaust vent shall be
installed in the outdoors or a well-ventilated
place where the exhaust gas emitted from the
vent does not flow into the indoors.
 The exhaust gas, if flowing into the indoors, may
cause carbon oxide poisoning.
Be sure to install the air intake and the exhaust
vent.
 Failure of ventilation may lead to incomplete
combustion due to oxygen deficiency, which may
eventually result in carbon oxide poisoning.
The boiler of the forced exhaust type (FE) can
not employ the multiple exhaust ducts.
 The reverse flow of the exhaust gas may cause
carbon oxide poisoning.
7

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The horizontal section of the chimney pipe shall
be installed to be inclined downward at an angle
of 5°, to prevent the condensed water or rain
from flowing in reverse into the boiler.
 Flow of the condensed water or rain into the
boiler may deteriorate the performance of the
boiler and shorten the life of the boiler.
r
■The exhaust duct type of the forced exhaust type (FE) boiler: the single exhaust type, the
chamber type, the shared exhaust type
■
The total length of the exhaust duct shall be kept to 10m or less, and the curved parts to 3
segments or less. (except for the curve on the edge point of the exhaust duct)
■ The connection size of the exhaust duct shall comply with the specifications. (Refer to the
specifications.)
■Care shall be taken to prevent the middle part of the exhaust duct from getting narrower. The
exhaust duct shall be installed to keep the radius of the curved part at maximum as possible.
■The exhaust duct shall be heat insulated with the non-flammable insulation material.
Installation of the chimney pipe for the forced exhaust type (FE) boiler