Saturn KDB - 161 GOM,KDB - 251 GOM,KDB - 201 GOM,KDB - 301 GOM User Manual

KDB-GOM

Series

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1. Specifications of the KDB-GOM series

1.1 Kyungdong Boiler Product Features and Functions

1.2 Specifications

2. Operating Types/Constructions/Schematic Diagram

2.1 Operating Types

2.2 Constructions of the Boiler

2.3 Schematic Diagram of Operating

3. Equipment Protection and Personal Safety

4. Specifications and Functions of the Major Components

4.1 Main Heat Exchanger

4.2 Fan Assembly

4.3 Circulation Pump

4.4 Modulating Gas Control Valve

4.5 3-Way Valve

4.6 Expansion Tank

4.7 Air Pressure Switch

4.8 Hot Water Flow Sensor

4.9 High Limit Sensor(Bimetal Type)

4.10 High Limit Fuse(Fuse Type)

4.11 Heating Temperature Sensor

4.12 Ignition Transformer

4.13 Power Transformer

4.14 Domestic Hot Water Heat Exchanger

4.15 Burner Assembly

4.16 Nozzle Holder Assembly

4.17 Wiring Diagram

4.18 Main Controller

I.

Technical Information

KDB-GOM

Series

- 2 -

THE KDB -GOM

THE KDB -GOMTHE KDB -GOM

THE KDB -GOM

KYUNGDONG BOILER’S VARIABLE-CAPACITY-MULTI-PURPOSE

82%+ HYDRONIC HEATING SYSTEM

How does it work?

The KDB-GOM provides 2 different heating functions that operate independently from the same boiler. One mode
provides space heating water to heat the home. The other mode provides a continuous circuit of hot water for domestic
use eg, bath, laundry, etc. Both circuits are separate and operate at different temperature ranges.

The space-heating water is controlled by the FR-5 thermostat. A special thermostat has been provided that enables the
user to either set the room temperature required of set the heating water temperature. In some cases this thermostat may
not be suitable for multi-system applications. (The installing contractor will make this determination and install suitable
alternative controls.

The domestic hot-water is controlled by the user. Because the KDB-GOM is a multi-purpose design, it can provide hot
water on demand, there is no storage tank to hold hot water, when there is no use for it. The KDB-GOM will only produce
hot water when you use it : instantaneous. The modulating gas burner allows water to heat up as evenly as it is being
used. The KDB-GOM will continue to heat the water until the source or sources are shut off. This on-demand-use also
helps to prevent water being held in the boiler for long periods of time.

IMPORTANT:

A thermostatic mixing valve should be installed on the domestic water supply pipe to control the supply water
temperature and prevent any possibility of scalding.

Domestic hot water priority

The GOM prioritizes bath water over space-heating water and will immediately stop producing space-heating water the
moment a hot water valve is opened anywhere in the home. Once the valve has been turned off, the boiler will return to
the home-heating function again.

The seal-combustion process

The KDB-GOM is designed with a special sealed-combustion venting process. Both sides of the combustion process
(inlet oxygen and outlet carbon monoxide) are isolated from each other and are totally sealed-off from the air supply within
the home. This reduces drafts, caused by infiltration, by as much as 82% making the KDB-GOM one of the safest, most
comfortable and clean-burning boilers in the world.

1. Specifications of the KDB-GOM series

1. 1 KyungDong GOM Product Features and Functions

A. Continuous Hot Water

Its On Demand! KyungDong Boiler makes running-out-of-hot-water obsolete.

B. Everything Built-in

Installs in half the time. We tried to think of all the parts and accessories you’ll need (plus a few you might have

forgotten) and built them into this multi-purpose hydronic heating system. You’ll spend less time driving to all the supply

houses.

KDB-GOM

Series

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C. Baked-in Beauty

The high quality porcelain finish is bake on and keeps the exterior looking new and lustrous for years to come.

D. System Timer

Save energy during times the home is unoccupied. Just set and activate the timer and leave. The unit turns off for
pre-programmed intervals until you return.

E. Room Thermostat FR-5

Convenient and accurate, large digital display is easier to read, easier to use. Our new room thermostat gives the
consumer digital control over several heating function.

F. Performance Indicator

With the use of the FR-5 electronic room thermostat, the (LED) will conveniently display the current operating
condition of the unit such as temperature of heating water, room temperature, normal operation, etc.

G. Continuous-Discharge Ignition(C.D.I.)

Direct ignition design requires no wasteful pilot burner and offers fuel savings.

H. Combustion Safety Protection

If the unit fails to ignite after the “ON” switch is pressed, or if the flame is extinguished due to a gas shortage, the
flame sensor will shut down the unit.

I. Always Balanced Operation

Despite fluctuating wind conditions, changes in atmospheric pressure and other external disturbances, the

variable-speed combustion blower provides steady performance.

J. Exhaust Safety Protection

While operating, the exhaust-discharge fan is continuously monitored. The units will be immediately stopped to
prevent fumes from entering the home if the wind gusts become excessive or if the flue exhaust has been clogged.

K. Smart Re-Start

Should the unit’s flame fail due to strong winds or temporary low gas pressure, the unit will automatically restart. In
cold weather climates, manual resets could cause freeze damage.

L. Safety Protection during Power Outages

When the power fails, the gas is automatically shut down and the units are stopped.

M. Automatic Fill & Refill

If for any reason the water level in the system drops to an unsafe level, makeup water will automatically fill to the
appropriate levels.

N. Automatic Air Bleed

Each unit has 2 built-in air bleed devices. One is manual and used for quick fill and venting convenience; the other
is air-activated and operates and automatically.

O. Removal of Impurities

Each unit come equipped with a built-in, clearable, heavy duty, particulate water filter for trapping impurities and
preventing the clogging of pipes. This is a maintenance item.

P. Air-Ratio Controller

Air ratio is monitored, adjusted and controlled prior to and during each operating cycle and will automatically adjust
the combustion rate. The air-ratio controller guarding against unsafe operating conditions also senses excessive
gusts of wind filling the flue system.

Q. Proportional Temperature Control

This control is designed to continually analyze water flow and usage while maintaining the outgoing water at a
constant, even temperature.

KDB-GOM

Series

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1.2 Specifications

GAS WALL-MOUNT

FRONT

View

A

Full, Dual Function Heating Design.

Natural and Propane Gas M odels.

B

Pow er-Vent, 2-Pipe C ombustion Process.

Modulating Gas for Precis ion Tem peratures.

REA R

Built-in Circulation Pump Assembly .

View

Built-in Ex pans ion Tank. Quiet, Vibration-Free Operation.

A

Built-in Freez e Protection.

Digitally Controlled, Full-Logic T hermostat.

C

Funct ion

SIDE Vi

ew

CENTR AL HEATING WATER

(LEFT

)

Const ructi on of Heat Exchanger

Heat Output (kcal/hr)

6,400

~ 16,

000

8,000

~ 20,

000

10,000

~ 25,

000

12,000

~ 30,

000

Max.Effici ency (%) 82 82 83 84

(wall)

Temperature Setting Range (℃)

Maxim um Working Pressur e (kgf/cm2)
Pre- Charged Ex pansion Tank (l iter ) 6.5 6.5 8.5 8.5

Circulation Pump

Freeze Protection Device

DOMESTIC HOT WATER

Heat Output (kcal/hr)

6,400

~ 16,

000

8,000

~ 20,

000

10,000

~ 25,

000

12,000

~ 30,

000

Max.Temperature Setting (℃)

Conti nuous DHW product ion

△T = 25 ℃

(liter )

10.7 13.3 16.7 20.0

Conti nuous DHW product ion △T = 33 ℃ (liter )

8 10.0 12.5 15.0

Conti nuous DHW product ion △T = 40 ℃ (liter )

6.7 8.3 10.4 12.5

C

Conti nuous DHW product ion △T = 50 ℃ (liter )

5.3 6.7 8.3 10.0

SIDE Vi

ew

Maxim um Working Pressur e (kgf/cm2)

(RIGHT)

OTHER DATA

Gas Type

Gas Consumption - LP (kg/hr)

1.58

1.98 2.48 2.97

(wall ) Gas Consumption (natural gas) (kcal/hr ) 19,000 23,700 29,700 35,600

Gas Inlet Supply Pressur e (natural: kPa) ( min - max)

Manifold Pressure (kPa) 0.16 ~ 0.92 0.16 ~ 0.96 0.25 ~ 0.94 0.14 ~ 0.96

Usage ( Heating & H ot Water )

Water Storage Capacity (liter) 0.7 0.7 0.8 0.8

Power (volts/cycle)

Power Consumption (watts)

Ignition

NOx Emi ssions

(Ref:0%, O2 in flue gas natural gas, ppm)

E F G D

Temp. of Exhaust Gas (℃)

WEIGHT AN D DIMENSIONS

Net Weight (l bs) 31 31 39 39

BOTTOM

A Physi cal Dimensions: Hei ght (mm) 630.0 630.0 685.0 685.0

View

B Wi dth (mm) 485 485 525 525
C Depth (mm) 235 235 250 250

D C onnection: Gas Inlet 15A, 1/2" 15A, 1/2" 20A, 3/4" 20A, 3/4"
E C onnection: Heating Water Supply/Return

B

F C onnection: Domestic H ot Water Supply/Return

(front) G C onnection: Primary Power (AC220V-50Hz)

H F lue Diameter (Intake / Exhaust) (mm)

TOP

H

Specif ication s s ubject to c hange with out prior not if ication

View ( wall )

- 2865 PELLISSIER PLACE - W HITTIER, CA 90601 - [phone]

15A, 1/2"

15A, 1/2"

70 / 75

28 (l ess than)

150 (l ess than)

20A, 3/4"

Dual

AC 220V- 50Hz

120 ~ 160

ELECT RONIC

80

17.5

Liquefied Petroleum ( L.P.) or Natural Gas

0.98 ~ 2.45

40 ~ 80

3

Self Pr imi ng

Ther mis tor

MODEL NUMBER

Combo Boiler

Stainl ess Steel / Copper

161 GOM 201 GOM 251 GOM 301 GOM

w ith 1-Year on Parts.

KYUNGDONG BOILER SPECIFICATIONS

C on trols Bo th Water F unction s Separ ately .

On-Demand Hot Water Delivery.

Com pact, Space-sav ing Design.

Limited Warranty on Heat Exc hanger

---- KEY FEATURES

Prov ides Hi-Temp Water for Heating the Home.

Pr ov ide s Hot Wate r fo r B athing & Wa s hing.

KDB - 161 / 201 / 251 / 301 GOM

Residential Gas Hydronic Heating System

GAS FIRED, WALL-MOUNT ED, MULT I-PURPOSE, HYDRONIC HEATING SYS T EMS

MODEL RAN GE : 16, 000 ~ 30,000 kcal/hr






KDB-GOM

Series

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2. Operating Types/Constructions/Schematic Diagram

2.1 Operating Types

Item Specification

Installation

Wall Mount Type

Flue Type

Both Use FF and FE

Usage

Both Use Heating and Domestic Water (Single Pipe, 2 Waterways)

Water Supply for

Heating

Maintain normally at a constant water pressure by pressure reducing valve

(Auto / Manual)

Control Method

Proportional Control Method by MICOM

Heat Exchanger Type

Single Dry Type (131/161/201GOM) and Single Wet Type (251/301/351GOM)

Combustion Method

Air Intake Method by Semi-Bunsen Burner

Gas Flow Control

Current Proportional Control Method by Thermistor

Heat Exchange

Method of Hot Water

y Heat Exchange Method : Indirect Heat Exchange by Secondary Heat Exchanger
y Heat Exchange Type : Plate Formed Brazing Heat Exchange
y Heat Exchange Circuit : Parallel Circuit

Ignition Method

Continuous Discharge, Direct Ignition Method

Heating

/

Domestic Water

Changeover

Heating Priority, Changeover to Domestic Water Circuit by 3-way Valve

Domestic Water Signal

Detect Flow by Flow Switch

y Motor : Condenser Type
y Casing : Engineering Plastic

Circulator Pump

y Impeller and Shaft Coupled : Magnetic Type

Expansion Tank

y Type : Expansion Tank
y Volume:6.5Liter(161/201GOM), 8.5Liter(251/301GOM)

Pressure Reducing /

Flow Limiting Control

and Water Hammering

Prevention

Control Pressure Reduction/Flow Limit and Prevent Water Hammering
by Diaphragm

KDB-GOM

Series

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2.2 Constructions of the Boiler

■

Model : KDB

Model : KDB Model : KDB

Model : KDB – 251 / 301 GO M

251 / 301 G OM 251 / 301 G OM

251 / 301 G OM

■

Model : KDB – 161 / 201GOM

KDB-GOM

Series

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2.3 Schematic Diagram of Operating

2.3.1 Schematic Diagram at the Heating Water Supply

High Limit Fuse

Fan Assembly

Heating Temperature

Sensor

Hot Water Flow Switch

Modulating
Gas Control Valve

Expansion Tank

Air Pressure Switch

Nozzle Holder Assembly

Burner Assembly

Flame Detector

Electrode

High Limit Sensor

②

Main Heat Exchanger

Exhaust Duct

③

3-Way Valve

Gas Inlet

Domestic Water Outlet

Tap Water Inlet

⑥

Heating Return

④

Heating Supply

⑦

Heating Strainer

①

Circulator Pump

Flue Exhaust

Heating Flow Sensor

Combustion Air Inlet

Domestic Water

Heat Exchanger

①

Circulator Pump → ② Main Heat Exchanger → ③ 3-Way Valve → ④ Heating Supply

⑦

Heating Strainer → ⑥ Heating Return → ⑤ Room Heating(Heating Coil, Radiator)

KDB-GOM

Series

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2.3.2 Controls of the Heating Temperature

2.3.2.1 When the heating water temperature is selected

- Setting Temperature: 40 ~ 80

℃

- To stop the run, turns the “HEATING WATER
TEMP.” dial to “OFF” position.

2.3.2.2 When the heating is controlled by the room
temperature

- Setting Temperature: 10 ~ 40

℃

- To stop the run, turns the “ROOM TEMP.” dial to
“OFF” position.

2.3.2.3 When the heating with the repetition time
(TIMER)

- The timer sets the stop time between 0 to 4-hours.

- Press the “TIMER” button, the boiler runs for 20­minutes and stops for the time set by the timer.

- The temperature of the heating water is
automatically set at 80 ℃ and the temperature
indicator displays the room temperature.

※

If the range of control has been exceeded due to the change in the set temperature or to abrupt change in

flow, the set temperature will be reached through the proportional control with the delay of 30±3 seconds.
If 83 ℃ is exceeded, the delay of 30±3 seconds will not be performed.

Control Range

Setting Temperature,

“T” set

ON OFF

Over 78

℃

63±2.0

℃

83±2.0

℃

70 ~ 77

℃

“T” set – (14±2.0)

℃

“T” set – (6±2.0)

℃

60 ~ 69

℃

“T” set – (12±2.0)

℃

“T” set – (6±2.0)

℃

50 ~ 59

℃

“T” set – (10±2.0)

℃

“T” set – (5±2.0)

℃

Below 49

℃

“T” set – (10±2.0)

℃

“T” set – (5±2.0)

℃

KDB-GOM

Series

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2.3.3 Schematic Diagram at the Domestic Water Supply

Fan Assembly

Heating Temperature

Sensor

②

Hot Water Flow Switch

Modulating
Gas Control Valve

ⓐ

Expansion Tank

Air Pressure Switch

Nozzle Holder Assembly

Burner Assembly

Flame Detector

Electrode

High Limit Sensor

ⓒ

Main Heat Exchanger

High Limit Fuse

Exhaust Duct

ⓓ

3-Way Valve

Gas Inlet

Domestic Water Outlet

Tap Water Inlet

Heating Return

Heating Supply

Heating Strainer

ⓑ

Circulator Pump

Flue Exhaust

Heating Flow Sensor

Combustion Air Inlet

③

Domestic Water

Heat Exchanger

③

Domestic Water

Heat Exchanger

Domestic Water Line

Heating Water Line

ⓒ

Main Heat Exchanger

④

Domestic

Water Outlet

②

Hot Water

Flow Switch

①

Tap Water Inlet

ⓓ

3-Way Valve

ⓑ

Circulator Pump

ⓐ

Expansion Tank

KDB-GOM

Series

- 10 -

2.3.4 Controls of the Domestic Water Temperature

2.3.4.1 Possible use of hot water in heating/not-at-home mode and hot water exclusive mode, according to the
flow volume detection of the hot water sensor.

2.3.4.2 Indirect control of the hot water temperature based on the heating water temperature.

2.3.4.3 Control at 80℃ when using hot water during heating.

2.3.4.4 Control at 70℃ when not-at-home or hot water exclusive mode

2.3.4.5 Stand by after hot water use

y when stopped after hot water use, the fan does not perform post purge and maintain the ON status for 90
seconds.

y the pump stops after the post purge (60 seconds)

y when using hot water again and after the hot water sensor detects the flow volume

pre-ignition Æ fuel supply Æ flame detection Æ post-ignition

y return to the before-hot-water-use status 90 seconds after the use of hot water.

2.3.4.6 Combustion in progress while in stand-by for hot water (90 seconds) or after 12 seconds of the post purge
time ( while in heating mode after the hot water sensor if “OFF”). Hot water stand-by time in progress separately.

3. Equipment Protection and Personal Safety

A. Ignition Failure

If the ignition fails, the gas supply is automatically cut off. An error code will appear as a flashing 2-digit code on the room

thermostat(models FR-5 only). The error codes are discussed in the troubleshooting section of the installation manual.

B. Flame Detection

If the fails and/or the re-ignition attempt fails, the gas supply is automatically cut off. An error code will appear on the room

thermostat(models FR-5 only).

C. Power Interruption

When the power is restored after a power failure, the boiler will automatically start and return to normal

operation(Manual reset is not required).

D. Excessive Air Pressure

Occasionally an excessive gust of wind from outside may be forced into the flue pipe. The air-ratio control module

will detect these strong back-drafts. To prevent any products of combustion from re-entering the building through the
open flue, the gas supply will be automatically cut off. An error code will appear on the room thermostat(models FR­5 only).

E. Explosive Re-ignition Protection

Abrupt, noisy startups and backfires are prevented by means of soft ignition, a trademark of our air-ratio control
module.

F. Overheat Protection

Any overheating of the burners or heat exchanger will automatically shut down the supply of gas to the burners.

An error code will appear on the room thermostat(models FR-5 only).

G. Low Water-Level Safety

Water levels in the heating pipes are continuously monitored to prevent the boiler from operating if there is no

water or a restricted flow through the piping. The boiler will automatically shut down and an error code will appear
on the room thermostat(models FR-5 only).

KDB-GOM

Series

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H. Automatic Water Fill

Should the water level in the system drop too low, a sensor will automatically activate the re-fill circuit.

I. Freeze Protection

During the heating season, a sensor inside the boiler will automatically detect and initiate safe heating cycles to prevent internal

equipment damage from occurring should freezing temperatures surround the boiler.

Note !

- When there is no gas supply
available, the circulating pump will automatically start up to guard the pipes from freezing (available only in boilers equipped with a
circulation pump).

J. Gas Pressure Control

To prevent internal damage from rupture, each boiler is protected from occasional surges in gas pressure by a regulating governor

device located in the gas valve.

K. Short-Circuit Protection

Any short-circuits occurring inside the boiler’s electrical circuit will immediately ‘blow’ the internal glass fuse(s)
and automatically cut off the gas supply.

L. Lightening Protection

Each boiler is specially grounded inside and out to protect against lightening strikes.

M. Combustion air flow control

When the combustion airflow is disrupted due to a defective, obstructed or an abnormal back-pressure of the
flue, the combustion is shut off safely.

N. Thermostat Control Failure

Should the thermostat fail to function properly, as a safeguard, the boiler’s gas supply will be automatically shut
down.

KDB-GOM

Series

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4. Specifications and Functions of the Major Components

4.1 Main Heat Exchanger

Item

161GOM 201GOM 251GOM 301GOM

Typ e

Single Dry Type Single Wet Type

Structure

Copper Fin＋Copper pipe Brazing

Function

- For use of heating and hot water, absorb generated heat from main burner and
then transmit it to heating pipe and hot water heat exchanger.

Number of Heat Fin

72 Fin 80 Fin 106 Fin 112 Fin

Material & Dimension

- Copper Pipe:C1220T-H(φ15.88).

- Heat Fin:C1220P-1/4H(t=0.4)

Heat Exchange Method

Instantaneous Method

KDB – 251 / 301 GOM

KDB – 161/201GOM

KDB-GOM

Series

- 13 -

4.2 Fan Assembly

Item

161GOM 201GOM 251/301GOM

Fan Type

Phase Controlled Air Intake Fan

Motor Type

Shading Coil Induction Motor Condenser Induction Motor

Blower Dimension

(mm)

φ

100 X 40L X 45 Fin

φ

134 X 40L X 60 Fin

Function

- Supply air needed for combustion and exhaust the remained gas before and after
combustion in order to prevent explosion in advance.

Bell Mouth(mm)

φ

60

φ

70 -

Rated Voltage

AC 220V, 50Hz

Power Consumption

Max.: 36.4 W, Min.: 14.0 W Max.: 75 W, Min.: 30 W

Casing

ALDC12

Blower

AL 5052

Material

Venture

ALDC12

KDB – 161 / 201GOM

KDB – 251 / 301GOM

KDB-GOM

Series

- 14 -

4.3 Circulation Pump

Item

All GOM models

Pump Type

Magnet Type

Motor Type

Single Phase, 2 Pole Induction Motor

Function

- Transmit the absorbed heat from main heat exchanger to heating pipe by
circulating heating water when use heating.

- Transmit the absorbed heat from main heat exchanger to hot water heat

exchanger by circulating heating water inside of boiler when use hot water.

Maximum Pump Head

10M(at 0 gal/ min )

Rated Voltage

AC 220V, 50Hz

Power Consumption

90 W

Condenser Capacity

2.5

㎌

Weight

2.45 kg

KDB-GOM

Series

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4.4 Modulating Gas Control Valve

Item

All GOM models

Model No.

UP 33 –06 (TIME CO.)

Rated Voltage

AC 220V, 50 / 60Hz

Power Consumption

8 W

Function

y Controls the flow of gas supply by the current value received from main

controller.

y Cut off the gas to prevent danger by the signal of sensor when happen troubles

caused by improper combustion.

Magnet Valve Proportional Valve

Schematic Diagram

SV1

(UV3)

SV2

(UV3)

PV

(UP2)

(SV1)

(SV2)

(PV)

Secondary pressure

Adjust Screw

Gas flow diagram

KDB-GOM

Series

- 16 -

4.5 3-Way Valve

Item

All GOM models

Rated Voltage

AC 220V, 50 / 60Hz

Power Consumption

3 W

Body Material

NYLON 66

Function

- Block the passage of heating water by the flow detection in flow switch and flow
heating water into the hot water heat exchanger when use hot water, and lead to
exchanging the heat of hot water with heating water in the hot water heat
exchanger. (When stop using hot water, the water passage is changed over to
the way of heating pipe automatically.)

Heating → Hot Water 10 ± 2 sec

Operating Time

Hot Water → Heating 10 ± 2 sec

Wire Identification

y RED : Heating, y BLUE : Hot Water y BLACK : Common

Model

Motor Speed

2.5 ~ 3 RPM

Direction of Motor

Rotation

CCW

KDB-GOM

Series

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4.6 Expansion Tank

NO. Part Name Material Remarks

1 Body SBHG1 , 2.0t

2 Bracket SBHG1 , 2.0t

3 Diaphragm BUTYL , 2.0t

4 Nipple S10C , PF3/8”

Item KDB – 161 / 201GOM KDB – 251 / 301GOM

Vol um e

6.5 Liter 8.5 Liter

Body Material

SBHG 1

Charging Gas

Nitrogen

Charging Pressure

1.0 kg/cm2 (14.2 psig)

Function

y Vent the generated air in the heating pipe.

y Absorbs pressure generated in the pipe by the expansion of heating water due to

increasing temperature of heating water.

y Maintain the water volume in the boiler at a constant by low water level sensor.

Nitrogen gas

Charging point

KDB-GOM

Series

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4.7 Air Pressure Switch

Item All GOM Model

Electric Rating

0.1A –125V AC, 0.1A –30V DC (Micro Switch)

Typ e

Differential Pressure Type (Vertical Type), Normal Close Type

Body Material

Nylon 66 (GF 30%)

Function

- Stop the combustion safely and automatically by monitoring the high pressure
or the adverse wind in the flue.

Contact Arrangement

ON more than 2.0 mmH2O

ON / OFF Operating

Pressure

OFF 7.0 ± 2 mmH

2

O

Reference

- Normal Close Type : The contact is always connected, and if the wind

pressure switch is operated by adverse pressure, this contact is opened and
stop the combustion in the boiler.

P3 (COM)

P1 (NC)

P2 (NO)

KDB-GOM

Series

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4.8 Hot Water Flow Switch

Item All GOM models

Body Material

Nylon 66 (GF 30%)

ON 2.3 ± 0.3 liter / min

Operating Flow

OFF 1.5 ± 0.5 liter / min

Installation Type

Horizontal Installation

Function

- When use hot water, detect the flow of hot water and transmit the signal to
controller, and operate 3-way valve to usable hot water.

- Reduce the pressure of discharging hot water in case of high water pressure
area (water supply pressure : more than 1.5 kgf/㎠) and maintain the optimum
condition of hot water use through flow limited by reduced pressure.

Reducing Pressure

Capability

P1 : 0.3 ～ 10 kgf/

㎠

→ P2 : 0.3

～

3.0 kgf/

㎠

Contact Rating

10 VA (W)

Maximum Contact Current

AC, DC 0.5A

Contact Resistance

less than 300 m

Ω

수동󰼿물보충

KDB-GOM

Series

- 20 -

4.9 High Limit Sensor (Bimetal Type)

Function

- When the bimetal plate in the high limit sensor detects the increase in the
heating water temperature or in causing surface temperature, it is
transformed to move the shaft and to let the contact “OFF”

- The “OFF” signal from the high limit sensor is sent to the controllers so that
the check lamp on the room thermostat comes “ON” and the failure code
NO. 16 is displayed on the temperature indication. When the running is
resumed, only the check lamp is kept “ON”.

- In case of reduced discharge of combustion exhaust or overheat of heat

exchangers, the high limit sensor automatically cut off the gas control valve to
close it when the send the sensed the temperature of the heat exchanger
reaches 95 ℃ or higher. The check lamp on the room thermostat is lit and
failure code NO. 1 is indicated on the indication panel.

Model MS-1, Manual Reset

Type Bimetal Type

Operating Temp. 95

℃

Structure

Recovery Temp.

80

℃

Voltage Rating 125 ~ 250 V

Electric Rating

Current Rating 15 A

[Automatic, MS-1]

KDB-GOM

Series

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4.10 High Limit Fuse (Fuse Type)

Function

- In case of abnormal overheat of heat exchanger, the temperature of sensor

part will be more than 195 ℃, high limit fuse will cut off the power of
modulating gas control valve to close the modulating gas control valve and
secure the safety.

- Check lamp will on in the room thermostat and failure code # 03 will be

indicated.

Type Fuse Type

Structure

Operation Temp. OFF point: 195

℃

Electric Rating

Resistance

61.1 Ω at 20

℃

KDB-GOM

Series

- 22 -

4.11 Heating Temperature Sensor

Item All GOM models

Model No.

DKS - 902ET - 330C

Resistance

R50 = 3.485 ㏀ ± 3%

B Constant

R0 / R100 = 3449 K ± 1%

Thermal Radiation Constant

0.7

mW /

℃

Thermal Time Constant

Within 10 seconds

Function

- Detect the temperature of heating water and transmit the signal
to main controller. The main controller controls the flow of air /
gas needed for achieving and maintaining the setting
temperature.

KDB-GOM

Series

- 23 -

4.12 Ignition Transformer

Function

- Electric energy provides high voltage and current to the main burner for
ignition of gas.

Primary Rating AC 220 V , 50 / 60 Hz

Secondary Rating 19 kVo-p±2

Power Requirement

Secondary Current

7 mA±2

Casing Non-Combustible ABS

Structure

Cable Silicon

KDB-GOM

Series

- 24 -

4.13 Power Transformer

Function

- Supply the power source to boiler.

Input Rating AC 220 V , 50 / 60 Hz

AC 220 V # 8-BLACK, # 9-GRY

AC 34.0 V # 2-RED, # 6-RED

AC 18.4 V # 1-ORANGE, # 5-BLUE

Power Requirement

Output Rating

AC 12.0 V # 4-WHITE, # 7-BROWN

Casing Non-Combustible ABS

Structure

Cable Silicon

KDB-GOM

Series

- 25 -

4.14 Domestic Hot Water Heat Exchanger

Item

161GOM 201GOM 251GOM 301GOM

Material

STS 304

Capacity

10 Pieces 12 Pieces 16 Pieces 18 Pieces

Function

- When use hot water, supply the heating water heated in main heat exchanger to hot water
heat exchanger and heat-exchange water (water supply) with heating water supplied in
hot water heat exchanger to be usable hot water.

Domestic Water

Outlet

Heating
Supply

Tap Water

Inlet

Heating
Return

KDB-GOM

Series

- 26 -

4.15 Burner Assembly

Item

161 / 201GOM 251 / 301GOM

Quantity of Secondary Nozzle

10 EA 15 EA

Material of Secondary Nozzle

ALSTAR

Slit (Flame Holder) Material

STS 430

Front Bracket

SBHG 1

Rear Bracket

STS 430

Function

- Supply heat sources by mixing and combusting the supplied gas and
air.

KDB-GOM

Series

- 27 -

4.16 Nozzle Holder Assembly

Item

161GOM 201GOM 251GOM 301GOM

Quantity of Primary Nozzle

10 EA 15 EA

Material of Primary Nozzle

C3602 BD

Material of Nozzle Holder

A6063S

LNG

φ

1.33

φ

1.46

φ

1.37

φ

1.50

Diameter of

Nozzle(mm)

LPG

φ

0.92

φ

1.06

φ

0.95

φ

1.06

Function

- Supply gas needed for combustion according to demands.

Secondary
gas pressure
measuring hole

KDB-GOM

Series

- 28 -

4

.17 Wiring Diagram

4

NO Function NO Function

1, 3

Gas Valve 1

7, 12

Ignition Transformer

2, 3

Gas Valve 2

8, 12

3-Way Hot Water

4, 11

AC 220V

9,13

3-Way Heating

5, 6

Circulation Pump

10

Ground

NO Function NO Function

1, 11

Water Filling

9, 20

Room Thermostat

2, 12

Fan

3, 13

Control Voltage

4

RPM Power Sourc e

14

RPM Input

5, 15

Heating Temp.

Sensor

15

RPM Ground

6 16

Flame Detector

7, 20

Air Pressure

Switch

17

Heating Flow Sensor

8, 20

Hot Water

Flow Switch

18, 19

Overheat

NO Function NO Function

1,5

AC 20V

4,7

AC 12V

2,6

AC 40V

8,9

AC 220V

3

AC 200V

4.17.3.3 21 Pin Wiring Connecting Diagram

4.17.3.2 9 Pin Wiring Connecting Diagram

4.17.3.1 13 Pin Wiring Connecting Diagram

4.17.3 Wiring Connecting Diagram

4.17.1 Fault repair codes (room thermostat, FR-5)

NO ON OFF

1

Trial Run Normal

2

Forced Max.

Combustion

Normal

3

Forced Min.

Combustion

Normal

4

FE FF

5

L.P. Gas Natural Gas

6

Close-Air Type Open Tank System

7

50 Hz 60 Hz

NO

161GOM 201GOM 251GOM 301GOM

8

OFF OFF ON OFF

9

ON ON OFF OFF

10

ON OFF ON ON

4.17.2 DIP S/W Setting on Main Controller

FND

No.

Problems FND

No.

Problems

01

Overheat

10

Air pressure failure

02

Low water level

11

Water level detection failure

03

Ignition failure

12

Flame failure in combustion

04

Flame sensor
(Lower gas pressure)

13

Heating water switch failure

05

Heating sensor wire
disconnected

14

Gas alarm(optional)

06

Short circuit of
heating sensor

15

MICOM failure

07

Hot water sensor wire
disconnected

16

Mechanical overheat

08

Short circuit of
hot water sensor

17

DIP switch setting error

09

Fan R.P.M. failure

18

KDB-GOM

Series

- 29 -

4.17.3 Wiring Diagram

WHT : WHITE
ORG : ORANGE

AC34V

AC220V

AC18.4V

IGNITION TRANS

LEGEND

GRY : GRAY

RED : RED

BLK : BLACK

BLK

2)BRN: Secondary valve

2)BLK: Currency

.
.

Modulation

YEL : YELLOW
BLU : BLUE

1)BLU : Primary valve

TIME UP 33-06

GAS VALVE

BLU

BLK

EV 1

BLU

BLU

RED

.
.

BRN

BRN

EV 2

HIGH LIMIT FUSE

2)BLK,BLU : HOT WATER

1)BLK,RED : HEATING WATER
THREE WAY VALVE

.
.

GRN

RED BLK

BLU

EARTH

AIR PRESSURE

: DC 5V : DC 5V

SWITCH

INPUT SIGNAL

HEATING FLOW

SWITCH

INPUT SIGNAL

: DC 20V

THERMOSTAT

INPUT SIGNAL

ROOM

: DC 5V

HOT WATER

FLOW SWITCH

INPUT SIGNAL

WHT

RED

SUPPLY POWER

BLK

WHT

FUSE , 3A - 2EA

PUMP

POWER TRANSFORMER

1)WHT : AC 5V

BLK

BLK

INPUT SIGNAL

: AC 200V

3)BLK : Ground

2)RED : DC 12V

FLAME

DETECTOR

EARTH

SUPERVISION

FAN ROTATION

BLK

RED

BLK

: DC 20V

YELYEL

GRN

PREVENTION

INPUT SIGNAL

OVERHEAT

SKYSKY

BLUBLU

ORG

BLK

RED

GRY

AC220V

: DC 5V

TEMPERATURE

HEATING WATER

INPUT SIGNAL

WHT

FAN

RED

RED

BLK

BLU

RED

RED

BLU

: DC 5 - 20V

68

F
50

176

3

86

99 4
F

2

Hrs

1

0

140

104

ORGORG

ALARM WIRE

INPUT SIGNAL

GAS LEAKAGE

BLK

BLK

RED

( - )

(+)

[13 PIN]

.

.

1

2

3

4

GRN : GREEN

BRN : BROWN

9

7

8

10

11

[9 PIN]

[21 PIN]

20

BLU

AC18.4V

RED

BRN

YEL

WHT

AC34V

AC12V

AC200V

AC12V

5

6

1

2

3

4

12

13

5

8

6

7

9

1

2

3

4

6

7

8

5

13

11

12

14

15

17

16

18

19

9

10

21

KDB-GOM SERIES WIRING DIAGRAM

AC220V, 50/60Hz

220VAC 50Hz

AC220V, 50Hz

AC220V, 50Hz

AC 220V, 50/60Hz

AC 220V, 50/60Hz

Operating Temp. : 156

°

C

KDB-GOM

Series

- 30 -

4.18 Main Controller

Voltage , Frequency AC 220V , 50 / 60 Hz

Voltage Range +10% to –15%

Ambient Temp. -15℃ to 70

℃

Electric Spec.

Ambient Humidity 45 – 90 %

Structure

Casing ABS

Model

KDC – 208-1M

4.18.1 DIP switch setting on main controller

4.18.2 Functions of Main Controllers

4.18.2.1 Pre-Purge

When the boiler operates, the function is to operate blower (fan) first and exhaust the remained air in the combustion

chamber before combustion starts, in order to prevent from immoderate ignition. Pre-Purge time is by achieving the fan’s

light-up RPM ± 200 rpm with more time than 4 ± 1 seconds.

4.18.2.2 Pre-Ignition

After Pre-Purge, the function is to operate ignition transformer previously in order to light up easily before supplying the
fuel (gas) for combustion. Pre-Ignition time is from ON time of ignition transformer till ON time of fuel supply device (gas
valve 2).

DIP Switch adjust part

Max. adjust screw
for secondary gas
pressure

NO ON OFF

1

Trial Run Normal

2

Forced Max.
Combustion

Normal

3

Forced Min.

Combustion

Normal

4

FE FF

5

L.P. Gas Natural Gas

6

Close-Air Type Open Tank System

7

50 Hz 60 Hz

NO

161GOM 201GOM 251GOM 301GOM

8

OFF OFF ON OFF

9

ON ON OFF OFF

10

ON OFF ON ON