MWH180EX
Service Manual
Instantaneous Gas Water Heater
(Residential Outdoor Unit)
Table of Contents
1. General Outline of Appliance
1-1 Features .......................................................................................................................................... 1
1-2 Specifications .................................................................................................................................2
1-3 Performance ...................................................................................................................................3
1-4 General Construction (Parts Names) .............................................................................................4
1-5 Main Component Structures ...........................................................................................................5
1-6 Main Safety Devices .......................................................................................................................9
1-7 Scale Build Up Alarm....................................................................................................................10
2. Installation and Related Work
2-1 INSTALLATION INSTRUCTIONS .................................................................................................11
2-2 DIMENSIONS ...............................................................................................................................16
2-3 SUGGESTED PIPING-BASIC INSTALLATION ............................................................................17
2-4 SUGGESTED PIPING-CIRCULATION SYSTEMS .......................................................................18
2-5 VENT PIPE INSTALLATION .........................................................................................................19
2-6 GAS LINE SIZING CHARTS ........................................................................................................20
2-7 GAS PIPING .................................................................................................................................21
2-8 WATER PIPING ............................................................................................................................21
2-9 PRESSURE RELIEF VALVE ........................................................................................................22
2-10 ELECTRICAL CONNECTION ......................................................................................................22
2-11 WIRING DIAGRAM .......................................................................................................................24
2-12 DIAGNOSTIC POINTS .................................................................................................................26
2-13 SCHEMATIC DIAGRAM ...............................................................................................................27
2-14 WIRING REMOTE CONTROLLER...............................................................................................28
2-15 MAIN REMOTE CONTROLLER CMR-2250 (P/N 3748) ..............................................................29
2-16 BATH REMOTE CONTROLLER YST-2250 (P/N 3749) ................................................................30
2-17 TESTING OPERATION ................................................................................................................31
3. Service and Maintenance
3-1 Operation Principles .....................................................................................................................32
3-2 Time Charts ..................................................................................................................................33
3-3 Flow Charts ..................................................................................................................................35
3-4 Fault Findings and Error Code......................................................................................................36
3-5 Gas Setting Procedure .................................................................................................................39
3-6 Combustion Specification, Various Combination Setting ..............................................................40
3-7 Remote Controllers Special Features ...........................................................................................42
3-8 Disassembling/Assembling Parts .................................................................................................44
3-9 Procedure for Flushing Water Heater ...........................................................................................53
3-10 Exploded View ..............................................................................................................................56
3-11 Parts List.......................................................................................................................................57
- 1 -
1. General Outline of Appliance
1-1 Features
1. High-performance & high-capacity water heater features
•Stable heating and supplying from 0.58 to 5.8 GPM with the proven temperature control
method combining the feed forward, feedback and water flow control.
• Design to reduce water temperature drops to hold temperature variation upon re-feeding
• Maximum flow rate of 5.8 GPM (22 L/min) allowing simultaneous hot water supply for
the kitchen and shower.
2. Environmentally-conscious and low NOx exhaust
•The rich-lean design of the combustion burners allows the value of NOx to be lower
than 55 ppm.
3. Self-diagnostic function
•Detects the scale-clogging of the heat exchanger assembly (warning).
•Detects the blocked exhaust system (alarm).
4. Improved reliability
•The potted PCB (Printed Circuit Board) and connectors equipped with retainers have
greatly improved the reliability of the electronic components.
5. The PCB has a function to let the LED flash upon heater trouble and the
remote controller has an error-display function.
6. With ultra-low power consumption, the optional remote controllers have
highly visible display (equipped with a backlight). The main remote controller
and the bath remote controller are different in design.
- 2 -
1-2 Specifications
Type of appliance Gas continuous flow water heater
Model number MWH-180EX
Type of
Installation
Hot water supply
Exhaust system
Outdoor only
Wall hanging
End stop system
Forced combustion
Power supply Appliance AC120V 60Hz Remote controller DC12V (digital)
Ignition system Direct electronic ignition
Outer panel material Pre-Painted Galvanized Steel Sheet
Hot water capacity
(water temp. +25°C rise) 0.58 ~ 5.8 GPM
Maximum hot water capacity
(54°F rise) 5.8 GPM
Maximum water supply pressure 150PSI (1.0MPa)
Recommended minimum water
supply pressure 15PSI (recommended 25-75 psi for maximum performance)
Minimum operational water flow 0.58GPM (2.2L/min)
Electrical comsumption
Normal 58W
Standby Main/Bath remote controller on 3.7 W
Anti-frost heater operation 84W
Connections
Gas
Water inlet
Hot water outlet
R3/4NPT
R3/4NPT
R3/4NPT
Exhaust temperature below 480°F
Noise level 49dB
NOx 55ppm Max.
Safety devices
Flame failure - Flame rod, Over heat switch 210°F, Over heat limit 203°F
Thermal fuse for heat exchanger 363°F, Over current - fuse (5A)
Automatic frost protection, Combustion fan motor rpm check - PCB
Dimensions Height 22 5/8" (575mm) Width 13 25/32" (350mm) Depth 6 1/2" (165mm)
Weight 40lbs. (18kg)
Temperrature Range Main remote controller 96 - 140°F
Bath remote controller 96 - 140°F
Available Default Temperatures
(without remote controller) 110°F, 120°F, 140°F, 165°F
(set by Dip switch on PCB)
Gas
consumption
Natural Gas
Propane Gas
Maximum 180,000Btu/h
(52.8kW)
Maximum 180,000Btu/h
(52.8kW)
Minimum (reference)
20,000Btu/h (6.0kW)
Minimum (reference)
20,000Btu/h (6.0kW)
Remote controller (option) CMR-2250 (P/N3748) Main control kitchen / laundry
YST-2250 (P/N3749) Bathroom control
Remote controller cable (option) Nonpolarized two core cable
Clearance from combustibles
Top of heater 12" (30.5cm)
Front of heater 24" (61.0cm)
Sides of heater 6" (15.2cm)
Back of heater 0" (0cm)
Floor 12" (30.5cm)
Carton box dimensions Height 30 1/8" (765mm) Width 15 15/16" (405mm) Depth 9 5/8" (245mm)
- 3 -
1-3 Performance
Performance-Capacity characteristic curves
Inlet water temperature
41°F (5°C)
50°F (10°C)
59°F (15°C)
68°F (20°C)
77°F (25°C)
6.3 GPM
6.3 GPM
5.8 GPM
0.58 GPM
0.5
96
0.58 GPM
0.5
96
0.58 GPM
5.8GPM5.8GPM
5.8GPM 5.8GPM
5.8GPM
0.5
96
0.58 GPM
0.5
96
0.58 GPM
0.5
96
0.58 GPM
0.5
96
1.0
2.0
3.0
4.0
5.0
Water flow rate [GPM]
6.0
7.0
8.0
10095 110 120
Hot water temperature [°F]
130 140 150 160 165
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
100
95 110 120 130 140 150 160
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
10095 110 120 130 140 150 160
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
10095 110 120 130 140 150 160
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
10095 110 120 130 140 150 160
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
10095 110 120 130 140 150 160
165 165
165
165
165
Water flow rate [GPM]
Hot water temperature [°F]
Water flow rate [GPM]
Hot water temperature [°F]
Water flow rate [GPM]
Hot water temperature [°F]
Water flow rate [GPM]
Hot water temperature [°F]
Water flow rate [GPM]
Hot water temperature [°F]
With water temperature 41°F (5°C) at inlet With water temperature 50°F (10°C) at inlet
With water temperature 59°F (15°C) at inlet With water temperature 68°F (20°C) at inlet
With water temperature 77°F (25°C) at inlet
- 4 -
1-4 General Construction (Parts Names)
No.
1
2
3
4
5
Description
Front Panel
Casing Assembly
Heat Exchanger
Exhaust Chamber Assembly
Gas Connection
Description
Water Filter Assembly
Drain Plug
Water Flow Sensor
Surge Protector
Water Flow Contorol Device
No.
11
12
13
14
15
No.
21
22
23
24
25
Description
Junction Box
Heat Exchanger Thermistor
Manifold Assembly
Flame Rod
Electrode
6Modulation Valve Unit
(Gas Control Assembly) Over Heat Switch
(bi-metal switch)
16 26 Frost Sencing Switch
(bi-metal switch)
7
8
9
10
Combustion Fan Motor Assembly
Transformer(100V)
Water Inlet
Hot Water Outlet
Outgoing Thermistor
Igniter Transformer
Thermal Fuse Device
PCB Unit
17
18
19
20
27
28
29
30
Burner Assembly
Combustion Chamber Assembly
Fuse(3.15A)
Fuse(5A)
15
8
18
25
23
3
4
26
2
27
6
14
30
20
29
24
28
21
1
16
7
19
22
17 511
9
13
10 1210 21
- 5 -
1-5 Main Component Structures
1. Gas flow control device
•Feeds the necessary amount of gas to heat water to a set temperature, based on the
amount of water flowing in through the inlet measured by the water flow sensor and the
water temperature calculation.
•When the thermistor detects the water temperature at the inlet, the temperature is com-
pared with the setting. An electric current representing the temperature difference is
transmitted to the PCB where the current is amplified and dispatched to the Modulating
Solenoid Valve.
•An electromagnetic force caused by the current from the PCB pushes the plunger up-
ward. <Upward force>
• Pressure received at the diaphragm due to internal pressure in the chamber of the
Modulating Solenoid Valve pushes the plunger downward. <Downward force>
•The plunger stops moving and stays at a certain position when the Upward and Down-
ward force are balanced.
•As the plunger remains at the position, the valve position of the Modulating Solenoid
Valve linked to the plunger is determined. This determines a "clearance" between the
valve body and the Modulating Solenoid Valve, establishing a necessary gas quantity.
The required amount of gas is then supplied to the main burner.
•If the temperature of the heated water is lower or higher than the setting, the resistance
of the hot water temperature detecting thermistor changes accordingly to automatically
adjust the gas amount by changing greater or lower the current transmitted to the Modu-
lating Solenoid Valve. This stabilizes the heated water temperature.
•When the gas supply pressure is changed, the receiving pressure of the diaphragm
changes and also changes the clearance between the valve body and the Modulating
Solenoid Valve. The gas is controlled to remain at a constant level.
- 6 -
Diaphragm
Plunger
Plunger spring
Coil
LP 13A
2121
10
20
96.5
82
OUT 2 OUT1
127.7
UP34-33C
13A
Modulating Solenoid Valve
Solenoid Valve
Filter
IN
Pressure check hole
- 7 -
2. Water flow sensor
* Measures the water flow as its rotor (bladed wheel) spins with the passing water. The
rotation of the rotor is detected by the sensor rotor (blade equipped with a magnet) of
the wheel and the Hall element which calculates the water quantity.
3. Water flow control device
* When water flows more than water
heater capacity, hot water temperature
becomes lower than the setting. The
water flow control device automatically
reduces the water flow to prevent such
temperature drops. If the water flow is
greater than the heater capacity, a
signal from the PCB activates the water
flow control device's motor (stepping
motor). In response to this operation,
the valve body of the water flow control
device also is operated to reduce the
water flow by narrowing the water path.
Water flow fluctuations are detected and
transmitted to the PCB by the water flow
sensor. When the appropriate level of
water flow is achieved, the PCB signals
the motor to stop. Thus, the water flow
remains at this level.
ø30
ø30
50
150 ° 20
Main body
Rotor
Hall element IC
Sealant
Inlet
50
ø30
28.5 29.5 35
Water flow
control device motor
Valve body
Valve main body
- 8 -
4. Combustion control of rich and lean burners
1) Ignition start
After the Main Gas Solenoid Valve, Gas Solenoid Valve 1, Gas Solenoid Valve 2 open
respectively as required, the Gas Modulating Solenoid Valve, being held at the slow igni-
tion position (with gas supply at a constant rate), operates to ignite rich burners and lean
burners.
2) During combustion
When a heating capacity higher than a certain level (approximately 95,000 BTU) is re-
quired, both Gas Solenoid Valve 1 and Gas Solenoid Valve 2 are opened to burn with rich
and lean burners while the gas supply is controlled by the Gas Solenoid Valve. When the
required heating capacity becomes lower than a certain level (approximately 110,000
BTU), the Gas Solenoid Valve 2 is closed while Gas Solenoid Valve 1 remains open to
combust with 12 rich burners, with the gas supply controlled by the Gas Modulating Sole-
noid Valve.
Gas
Gas Solenoid Valve 2
Gas Solenoid Valve 1
Combustion fan
Electrode Flame rod
Main burner
Gas Modulating
Solenoid Valve
Main Gas
Solenoid Valve
- 9 -
1-6 Main Safety Devices
1. Water flow sensor (Boil-dry protection)
When the water flow sensor detects the flow rate set for starting ignition (ignition water
flow) or higher, the water heater starts operation.
Ignition water flow: 0.71 GPM (2.7 L/min.)
Extinction water flow: 0.58 GPM (2.2 L/min.)
2. Flame rod (Flame failure detection)
Electric signals are transmitted to the flame detection circuit to confirm the normal com-
bustion when the flame rod detects the rectification of normal combustion flame. There-
fore, if the combustion of the burners is not normal, the signals are not sent via the flame
rod. The gas control assemblies are closed without the signals and the error code "111"
or "121" is displayed on the remote controllers. (Normal with 0.8 A or higher)
3. Thermal fuse (Over-temperature protection system)
The thermal fuse is placed around the heat exchanger assembly. If the ambient tempera-
ture inside the water heater becomes extremely high, the fuse will melt down to break the
power circuit. In such a case, as no power is supplied to the gas control assemblies, the
gas supply is stopped and the combustion is stopped.
(The system is activated to blow the fuse at 363F [184C].)
4. Over heat switch (residual)
Even if the heat exchanger assembly is over heated by no-water combustion, every gas
path is closed to avoid risks. At this time, the error code "141" is displayed on the remote
controllers.
(The switch is provided with a auto-restoration function and turns OFF at 212F [100C].)
5. Fan revolution detection device (Hall IC)
The device detects the fan revolution speed to control the air supply necessary for normal
combustion. If the fan revolution is out of the preset standard range, the gas control as-
semblies are closed to stop the combustion before combustion failure occurs. In this case,
the error code "611" is displayed on the remote controllers.
6. Anti-freeze system (Frost sensing switch and heater)
To prevent freezing in the hot water supply circuit, anti-frost heaters are provided at major
points of water flow paths in the unit. The heaters are activated by the thermistors in the
unit.
The 4 heaters, one located on the front side of heat exchanger is 48W, the water supply
pipe is 16W, the connection of water inlet is 10W and the connection of hot water outlet is
10W. In order to keep the heat is the most vulnerable part of heat exchanger, the big
capacity 48W heater is mounted.
(The system turns ON at 37F [3C] and OFF at 55F [13C].)
- 10 -
1-7 Scale Build Up Alarm
Summary
The temperature of residual hot water becoms higher as scale starts to build up inside the
heat exchanger. The extent of scale build up is judged by monitoring the temperature of re-
sidual hot water. “LC”, scale build up alarm, is indicated on the remote controller.
Flow chart (See page 35)
1) The set temperature by remote controller needs to be 120F and over to activate the
alarm.
2) The stability of the temperature of outgoing hot water is detected by the thermistor of
the can body.
3) The temperature of residual hot water is detected by the thermistor of the can body
when hot water flow is stopped. The criterion for judging scale build up varies depending
on combustion capacity.
4) “LC” alarm and set temperature are indicated alternately on the remote controller.
Alarm specification
* Hot water supply is available even if “LC” is indicated on the remote controller.
* ”LC” alarm can be reset by turning the power switch off and on.
* No detection is possible in case remote controller is disconnected.
* ”LC” alarm is not memorized in the alarm history record.
Conditions for invalid detection
* The thermistor of the can body is broken or short-circuited.
* The alarm is in process.
* During forced combustion by the dip switch.
* The set temperature is under 120F.
- 11 -
2. Installation and Related Work
2-1 INSTALLATION INSTRUCTIONS
• The cases shown below are classified by the degree of risk and damage.
Be sure to follow the instruction for your safety.
"Danger" indicates that serious injuries or even death may result from the
improper installation due to negligence of following the instructions.
"Warning" indicates the possibility that serious injuries or even death may
result from the improper installation due to negligence of following the
instructions.
"Caution" indicates the possibility that some injuries or material damage
may result from the improper installation due to negligence of following the
instructions.
Each mark indicates:
General prohibited
Danger
Warning
Caution
Never fail to do.
Ground
Never install the unit indoors as it is exclusively for outdoor use.
Do not install it in the bathroom. Electric shock or leakage may result.
Danger
• Read and understand the installation manual to carry out the installation as specified for
proper and safe usage.
• A competent dealer or plumber should perform the complete installation, including
placement, plumbing, gas line, and electrical connection.
Consumers should not try to install their own unit.
• Make double sure that the unit runs in accordance with the check items of "trial run"
standard after it is installed. (refer to Testing operation)
• When installation of water heater, be sure to wear protective equipment to prevent
injuries and burns.
After installation, do not enclose the unit with anything such as corrugated sheets, which
may develop an indoor-like closed environment. It poses serious danger due to the
shortage of oxygen or imperfect combustion.
• If the supply water pipe is incorrectly connected to the gas inlet, do not attempt to operate
the unit by simply reconnecting the pipe correctly, this will only cause further damage to
the unit.
Corrective measures
• It will be necessary to replace all the internal gas components if the gas piping is hooked
up incorrectly.
Warning
To the installers.
- 12 -
• Make sure the unit to be installed suits the
intended use and application.
• Do not use any gas other than specified on the
sticker.
• Do not operate with any power source
(voltage/frequency) other than specified on the
sticker.
Verification of the unit.
Before installation.
Ventilation
• Install the unit where there is enough space for ventilation.
• Do not install the unit where flammables such as gasoline, benzene, and adhesive are
handled.
• This unit does not allow the use of extended exhaust pipes.
• Install the unit as far as possible, away from anything in front or above even if it is non-
combustible in order to prevent exhaust gas recirculation, and staining of surfaces.
• Take preventive measures against snow drifts for air inlet and exhaust outlet to stay
unaffected in case there is a possibility that they may be blocked by snow fall.
Location of the unit.
Decide where to install the unit by considering customer’s request and clearances.
Warning
Warning
DIRECT VENT AUTOMATIC INSTANTANEOUS GAS WATER
HEATER FOR INDOOR INSTALLATION
NATURAL GAS / PROPANE GAS
CHAUFFE-EAU INSTANTAN AUTOMATIQUE ¸ VENT DIRECT
POUR INSTALLATION INT RIEUR.
NAT / GPL
ANSI Z21.10.3-2004
CSA 4.3-2004
Wiring Diagram inside Front Cover
Sch ma du c blage derri re le couvercle avant.
Minimum clearances from combustible of non-combustible construction
D gagements minimaux assurer entre les parois de l«appareil et les constuctions combustibles ou
incombustibles
Back: 0 inch 0 po arri re
Front:24 inches 24 po devant d«appareil
Top: 12 inches 12 po dessus
Side: 6 inches 6 po c t s
FOR YOUR SAFETY
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
This water heater is required to have with a pressure relief valve. For safe operation of the water
heater the relief valve must not be removed from its designated point of installation or plugged.
POUR VOTRE SÉCURITÉ
Ne pas entreposer ne utiliser d«essence ne d«autres vapeurs ou liquides inflammables proximit
de cet appareil ou de tout autre appareil.
Ce chauffe-eau d it tre installer avec un soupape de d charge. Pour assurer le fonctionnement
s curitaire du chauffe-eau, ne pas retirer ni obturer cette soupape de d charge.
PROPANE GAS (GPL)NATURAL GAS (Gaz Naturel)MODEL : MWH180EX
180,000 Btu/h180,000 Btu/h
MAX. INPUT
Debit calorifique max.
20,000 Btu/h20,000 Btu/h
MIN. INPUT
Debit calorifique min.
14.0 inches W.C.
14.0 pounces W.C.
10.5 inches W.C.
10.5 pounces W.C.
GAS PRESSURE INLET MAX.
Pression de gaz entr e max.
8.0 inches W.C.
8.0 pounces W.C.
4.0 inches W.C.
4.0 pounces W.C.
GAS PRESSURE INLET MIN.
Pression de gaz entr e min.
3.10 inches W.C. (2.75)
3.10 pounces W.C. (2.75)
2.75 inches W.C. (2.55)
2.75 pounces W.C. (2.55)
GAS PRESSURE MANIFOLD MAX.
Pression d«admission max.
0.4 inches W.C.
0.4 pounces W.C.
0.4 inches W.C.
0.4 pounces W.C.
GAS PRESSURE MANIFOLD MIN.
Pression d«admission min.
AC 120V — 60Hz
ELECTRICAL RATING
Regime nominal lectrique
150 PSI
MAX. WATER PRESSURE
Pression d eau max.
20511090
For the safety and the proper usage.
Read and understand "IMPORTANT ISSUES TO
BE NOTED IN PARTICULAR" before the use.
The cases shown below are classified by the
degree of risk and damage.
Be sure to follow the instruction for your safety.
Linstruction securit pour l usage de MWH180.
Lisez et comprendrez Instructions de securit
avant utilisation avant usage.
Les situations suivant sont cat goris par le degr
de risque et danger.
Suivez les instructions exactement pour votre
securit .
Danger
¥ Attention au fuite de gaz. (Peut r sulter en feu)
¥ Ne jamais installer le chauffe-eau a l interieure
car il est exclusivement pour usage a l ext rieur.
¥ Ne pas installer dans la sale de bain. (choc
lectrique ou une fuite de l eau peut resulter)
Danger
¥ Watch for gas leak (May cause fire.)
¥ Never install the unit indoors as it is exclusively
for the outdoor use.
¥ Do not install it in the bathroom. Electric shock
or leakage may result.
Avertissement
¥ Attention a pr venier des br lures.
¥ Confirmez le type de gaz et la puissance
lectrique.
¥ Payez attention aux enfants. (pr venir des
br lures)
¥ Pas de d montage, r paration ou modification.
( tre cause du feu, choc lectrique ou d outre
accidents)
¥ Ne pas place des mat riaux combustible pr s
du chauffe-eau.
¥ Ne touchez pas le chauffe-eau pendant
op ration ou juste apr s terminer l op ration.
¥ N employez aucun gaz autre que sp cifique
sur l tiquette.
Warning
¥ Caution to prevent scalding.
¥ Confirm type of gas and power supply.
¥ Pay attention to children. (Cause of accident.)
¥ No disassembly, repair or modification. (May
cause fire, electric shock or other accidents.)
¥ Caution for flammable items.
¥
Do not touch water heater during or immediately
after operation.
¥ Do not use any gas other than specified on the
sticker.
ONLY FOR USE WITH
REFER TO THE LOCAL GAS AUTHORITY FOR CONFIRMATION ON THE GAS TYPE, IF IN DOUBT
.
DO NOT REMOVE THIS LABEL UNTIL THE APPLIANCE HAS BEEN INSTALLED AND TESTED
Si vous ne savez pas le type de gaz, contactez le fournisseur de gaz ou les autorit locaux.
Enlevez pas cette etiquette jusqu« l«appareil a t installer et verifie.
NATURAL GAS
SERIAL NUMBER
Manufactured for: MONITOR PRODUCTS INC. Ref.: New Jersey
20511040
DIRECT VENT AUTOMATIC INSTANTANEOUS GAS WATER
HEATER FOR INDOOR INSTALLATION
NATURAL GAS / PROPANE GAS
CHAUFFE-EAU INSTANTAN AUTOMATIQUE ¸ VENT DIRECT
POUR INSTALLATION INT RIEUR.
NAT / GPL
ANSI Z21.10.3-2004
CSA 4.3-2004
Wiring Diagram inside Front Cover
Sch ma du c blage derri re le couvercle avant.
Minimum clearances from combustible of non-combustible construction
D gagements minimaux assurer entre les parois de l«appareil et les constuctions combustibles ou
incombustibles
Back: 0 inch 0 po arri re
Front:24 inches 24 po devant d«appareil
Top: 12 inches 12 po dessus
Side: 6 inches 6 po c t s
FOR YOUR SAFETY
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
This water heater is required to have with a pressure relief valve. For safe operation of the water
heater the relief valve must not be removed from its designated point of installation or plugged.
POUR VOTRE SÉCURITÉ
Ne pas entreposer ne utiliser d«essence ne d«autres vapeurs ou liquides inflammables proximit
de cet appareil ou de tout autre appareil.
Ce chauffe-eau d it tre installer avec un soupape de d charge. Pour assurer le fonctionnement
s curitaire du chauffe-eau, ne pas retirer ni obturer cette soupape de d charge.
PROPANE GAS (GPL)NATURAL GAS (Gaz Naturel)MODEL : MWH180EX
180,000 Btu/h180,000 Btu/h
MAX. INPUT
Debit calorifique max.
20,000 Btu/h20,000 Btu/h
MIN. INPUT
Debit calorifique min.
14.0 inches W.C.
14.0 pounces W.C.
10.5 inches W.C.
10.5 pounces W.C.
GAS PRESSURE INLET MAX.
Pression de gaz entr e max.
8.0 inches W.C.
8.0 pounces W.C.
4.0 inches W.C.
4.0 pounces W.C.
GAS PRESSURE INLET MIN.
Pression de gaz entr e min.
3.10 inches W.C. (2.75)
3.10 pounces W.C. (2.75)
2.75 inches W.C. (2.55)
2.75 pounces W.C. (2.55)
GAS PRESSURE MANIFOLD MAX.
Pression d«admission max.
0.4 inches W.C.
0.4 pounces W.C.
0.4 inches W.C.
0.4 pounces W.C.
GAS PRESSURE MANIFOLD MIN.
Pression d«admission min.
AC 120V — 60Hz
ELECTRICAL RATING
Regime nominal lectrique
150 PSI
MAX. WATER PRESSURE
Pression d eau max.
20524910
For the safety and the proper usage.
Read and understand "IMPORTANT ISSUES TO
BE NOTED IN PARTICULAR" before the use.
The cases shown below are classified by the
degree of risk and damage.
Be sure to follow the instruction for your safety.
Linstruction securit pour l usage de MWH180.
Lisez et comprendrez Instructions de securit
avant utilisation avant usage.
Les situations suivant sont cat goris par le degr
de risque et danger.
Suivez les instructions exactement pour votre
securit .
Danger
¥ Attention au fuite de gaz. (Peut r sulter en feu)
¥ Ne jamais installer le chauffe-eau a l interieure
car il est exclusivement pour usage a l ext rieur.
¥ Ne pas installer dans la sale de bain. (choc
lectrique ou une fuite de l eau peut resulter)
Danger
¥ Watch for gas leak (May cause fire.)
¥ Never install the unit indoors as it is exclusively
for the outdoor use.
¥ Do not install it in the bathroom. Electric shock
or leakage may result.
Avertissement
¥ Attention a pr venier des br lures.
¥ Confirmez le type de gaz et la puissance
lectrique.
¥ Payez attention aux enfants. (pr venir des
br lures)
¥ Pas de d montage, r paration ou modification.
( tre cause du feu, choc lectrique ou d outre
accidents)
¥ Ne pas place des mat riaux combustible pr s
du chauffe-eau.
¥ Ne touchez pas le chauffe-eau pendant
op ration ou juste apr s terminer l op ration.
¥ N employez aucun gaz autre que sp cifique
sur l tiquette.
Warning
¥ Caution to prevent scalding.
¥ Confirm type of gas and power supply.
¥ Pay attention to children. (Cause of accident.)
¥ No disassembly, repair or modification. (May
cause fire, electric shock or other accidents.)
¥ Caution for flammable items.
¥
Do not touch water heater during or immediately
after operation.
¥ Do not use any gas other than specified on the
sticker.
ONLY FOR USE WITH
REFER TO THE LOCAL GAS AUTHORITY FOR CONFIRMATION ON THE GAS TYPE, IF IN DOUBT
.
DO NOT REMOVE THIS LABEL UNTIL THE APPLIANCE HAS BEEN INSTALLED AND TESTED
Si vous ne savez pas le type de gaz, contactez le fournisseur de gaz ou les autorit locaux.
Enlevez pas cette etiquette jusqu« l«appareil a t installer et verifie.
PROPANE GAS
SERIAL NUMBER
Manufactured for: MONITOR PRODUCTS INC. Ref.: New Jersey
20511040
or
- 13 -
• Reinforce the wall if necessary as this unit weighs about 40lbs.
Caution
Installation.
1. Twist 1 screw (for wall hanging) into the wall leaving about 1/8inches (4mm) length to
hook on.
2. Hook the center hole of the wall hanging bracket onto the screw and securely fix the unit
with 4 screws.
Screw
(for wall hanging)
Wall hanging bracket
Screw
(for wall hanging) Wall hanging bracket
About 1/8"
(4mm)
23 1/32" (585mm)
Screw
(for wall hanging)
Screw
(for wall hanging)
Screw
(for wall hanging)
- 14 -
Caution
• Check if adjacent wall or ceiling is fire resistant and allows safe distance for fire prevention.
• This water heater is suitable for residential water (potable) heating only. Do not use this
water heater for space heating, combination space heating/domestic water heating, or
commercial water heating applications.
• MWH-180EX is not suitable for use in pool or spa applications.
• Maintain proper space around the unit for proper servicing and operation. Minimum
clearances from combustible materials are listed below.
Note : These clearances do not apply if installing unit into an MPI recess box, however
they do apply from the exhaust port to combustible once the exhaust port comes
out of the recess box.
• Do not install MWH-180EX under an overhang less than 3feet from the top of the unit.
When the overhang protrudes out over MWH-180EX greater than 3feet, the area under
the overhang must be open on 3sides.
• When the water heater is installed within a recess box, the clearances from the top, bottom,
sides, and back surfaces of the recess box to combustible materials are 0inch.
The clearance from combustibles from the front of the recess box is 24inches.
• Secure enough space so that the inspection and repairs can be done easily.
• Secure space not only in front but also under the unit.
• Do not install the unit over other combustion appliances such as gas cooking stove or a
range.
Oil residue and dust in the air can adhere to the burner and the heat exchanger resulting in
deformation, loss of efficiency, or damage to electronic components.
• Do not install the exhaust outlet near the outlets of the other appliances.
Install the air inlets away from the wind path as the wind may cause imperfect combustion.
• Do not install the unit where commercial chemicals are used.
Those chemicals are ammonia, sulfur, chloride, ethylene compound and acids which are
used at beauty shop, laundry, factory and so forth.
• Do not install the unit over food or dishes.
• Installer must install a Pressure relief valve.
Pipe pressure relief to a drain or outside environment, or within 4inches of the floor.
Pipe pressure relief discharge to a drain or outside environment. (refer to page 22)
• The appliance should be located in an area where leakage from the unit or connections will
not result in damage to the area adjacent to the appliance or to lower floors of the
structure. When such locations can not be avoided, it is recommended that a suitable drain
pan, adequately drained, be installed under the appliance. The pan must not restrict
combustion airflow.
Top of heater
Front of heater
Sides of heater
Back of heater
Floor
12"
24"
6"
0"
12"
(30.5cm)
(61.0cm)
(15.2cm)
(0cm)
(30.5cm)
- 15 -
•Ensure a minimum of 24inches (60.96cm) clearance for the exhaust stream in non-public
spaces.
Ensure a minimum of 48inches(121.92cm) clearance for the exhaust stream in public spaces.
• Install the unit where there will be adequate distance from windows as shown in the diagram
below.
Pay special attention to distances from windows on adjacent buildings on both sides.
Definition of Clearances from Openings in the Building
Building openings refer to the windows of the building, or any openings resulting from an
open door or sliding doors or windows. It does not include sky lights or the fixed part of a
single sliding window.
• Do not install the unit so that the exhaust gas directly hits against any reinforced glass plate.
The glass may crack or break due to the exhaust heat.
•Do not install the unit near plants, pets, or low heat resistant plastic products that are
susceptible to the exhaust heat. The plants may wither and the pets may die.
• In non-public areas the minimum height from the floor to the exhaust is 84inches (213.36cm).
• If there is an overhanging eave ensure that there is a minimum of 12inches (30.48cm)
clearance.
windows to the side
windows above heater
6" or more 6" or more
6" or more
12" or more
Install the unit so that clearances
from opening are as shown in the
shaded area.
24" or more 48" or more
*code is NFPA 211
84" or more
12" or less
the public spacethe private balcony
handrail
hanging wall
Installation.
- 16 -
23 1/32"
(585mm)
22 5/8"
(575mm)
13 25/32"
(350mm)
3 15/16"
(100mm)
2 3/8"
(60mm)
1 5/16"
(33.5mm)
4 15/32"
(113.5mm)
3 13/16"
(97mm)
2 25/32"
(71mm)
3 9/16"
(97mm)
1 31/32"
(50mm)
6 1/2"
(165mm)
19/32"
(15mm)
15/32"
(12mm)
2-2 DIMENSIONS
- 17 -
2-3 SUGGESTED PIPING-BASIC INSTALLATION
Minimum 3/4"
Hot water supply line
Minimum 3/4"
Cold water supply line
Minimum 3/4"
Gas supply
Shut off valve
Valve 3 Valve 4
Pressure relief valve
Drain
UnionUnion
Union
This drawing is intended only as a guide.
It does not imply compliance with local building codes.
Installation must be done in accordance with local building
codes and may vary depending on installation location.
Confer with local building officials before installation.
Valve 2Valve 1
- 18 -
Hot water return
Pressure relief valve
Drain
Check valve
Check valvePump
Storage tank
Fixtures
Minimum 3/4"
Hot water supply line
Minimum 3/4"
Cold water supply line
Minimum 3/4"
Gas supply
Union
Shut off valve
Union
This drawing is intended only as a guide.
It does not imply compliance with local building codes.
Installation must be done in accordance with local building
codes and may vary depending on installation location.
Confer with local building officials before installation.
Union
Union
Valve 3 Valve 4
Valve 2Valve 1
2-4 SUGGESTED PIPING-CIRCULATION SYSTEMS
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