Noritz NC250-SV-ASME User manual

SBA8377
Rev. 09/09
Models : NC250-SV-ASME
NC250-DV-ASME
TANKLESS GAS WATER HEATER
Owner’s Guide
NORITZ America Corporation
Thank you for purchasing this Noritz Tankless Gas Water Heater.
Before using, please:
Read this manual completely for operation instructions.
Completely fill out the warranty registration card (included separately) and
mail the detachable portion to Noritz America Corporation.
Keep this manual (and the remainder of the warranty registration card) where it
can be found whenever necessary.
Installation must conform with local codes, or in the absence of local codes,
the National Fuel Gas Code, ANSI Z223.1/NFPA 54.
Noritz America reserves the right to discontinue, or change at any time, the
designs and/or specifications of its products without notice.
- Do not store or use gasoline or other flammable vapors and liquids in the
vicinity of this or any other appliance.
-WHAT TO DO IF YOU SMELL GAS
•Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from a neighbor’s phone. Follow the
gas supplier’s instructions.
•If you cannot reach your gas supplier, call the fire department.
- Installation and service must be performed by a qualified installer, service
agency or the gas supplier.
If the information in this manual is not followed exactly, a fire or explosion
may result causing property damage, personal injury, or death.
WARNING
Low NOx
Approved by
SCAQMD
CERTIFIED
R
Accepted For Use
City of New York
Department of Buildings
MEA 19-03-E
*SBA8377*

2
Prohibited Don’t
touch.
Don’t
disassemble
the equipment.
Don’t touch
with a wet
hand.
No flame.
High
Temperature.
To prevent damage to property and injury to the user, the icons shown below will be used to warn of
varying levels of danger.
Every indication is critical to the safe operation of the water heater and must be understood and observed.
Potential dangers from accidents during installation and use are divided into the following four
categories. Closely observe these warnings; they are critical to your safety.
Other icons
DANGER
WARNING
CAUTION
DANGER indicates an imminently hazardous situation which,
if not avoided, will result in death or serious injury.
WARNING indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
CAUTION indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury.
CAUTION used without the safety alert symbol indicates a potentially
hazardous situation which, if not avoided, may result in property damage.
CAUTION
Be sure
to do. Ground.
Electric
Shock.
DANGER
Icons warning of risk level
Important Safety Information-1
This is the safety alert symbol. It is used to alert you to potential personal injury hazards.
Obey all safety messages that follow this symbol to avoid possible injury or death.
Vapors from flammable liquids will explode and catch fire causing death or severe burns.
Do not use or store flammable products such as gasoline, solvents or
adhesives in the same room or area near the water heater.
Prohibited
Keep flammable products:
1. Far away from the water
heater.
2. In approved containers.
3. Tightly closed.
4. Out of children’s reach.
Vapors:
1. Cannot be seen.
2. Vapors are heavier than air.
3. Go a long way on the floor.
4. Can be carried from other rooms
to the main burner by air currents.
Hot Water Heater temperatures over 125 °F can cause severe burns instantly or
death from scalding.
Children, disabled and elderly are at the highest risk of being scalded.
Feel water temperature before bathing or showering.
Temperature limiting valves are available, ask professional person.
Prohibited
(Continued)

3
No flame.
(Continued)
[NC250-SV-ASME only]
Do not use the water heater if
the exhaust pipe is displaced,
has holes, is clogged or is
corroded.
Prohibited
WARNING
Be sure
to do.
When a gas leak is noticed:
1. Stop use immediately
2. Close the gas valve
3. [When installing indoors]
Open windows and doors
If you detect abnormal combustion
or abnormal odors, or during an
earthquake, tornado or fire:
1. Turn off the hot water supply
2. Turn off the power to the water heater
3. Turn off gas and water supply valve.
4. Call the nearest Noritz agent
Be sure
to do.
Do not allow anyone to change the water temperature while hot water is being used.
To prevent scalding, do not change the water temperature to a higher setting.
Prohibited
Check the temperature of
the running hot water
before entering the shower.
Check the temperature
before stepping into
the bath tub.
High
Temperature.
Explosion Hazard ;
If the temperature and pressure relief
valve is dripping or leaking, have a
qualified service technician replace it.
Do not plug or remove the valve.
Failure to follow these instructions can result in
fire or explosion, and personal injury or death
Prohibited
(Continued)
A. This water heater does not have a
pilot. It is equipped with an
ignition device that automatically
lights the burner. Do not try to
light the burner by hand.
B. BEFORE OPERATING smell all
around the water heater area for
evidence of leaking gas. Be sure
to smell next to the floor because
some gas is heavier than air and
will settle on the floor.
WHAT TO DO IF YOU SMELL GAS.
• Do not try to light any
appliance.
• Do not touch any electrical
switch; do not use any phone
in your building.
• Immediately call your gas
supplier from a neighbor’s
phone. Follow the gas supplier’s
instructions.
• If you cannot reach your gas
supplier, call the fire department.
C. Use only your hand to turn the
gas valve knob. Never use tools.
If the knob will not turn by hand,
don’t try to repair it. Call a
qualified service technician.
Force or attempted repair may
result in a fire or explosion.
D. Do not use this water heater if
any part has been under water.
lmmediately call a qualified
service technician to inspect the
water heater and to replace any
damaged parts.
Prohibited
[NC250-DV-ASME only]
Do not use the water heater if
the intake/exhaust pipe is displaced,
has holes, is clogged
or is corroded.
Carbon Monoxide Poisoning
Hazard. Do not install this water
heater in a mobile home, recreation
vehicle or on a boat.
Prohibited

4
Important Safety Information-2
(Continued)
Be sure the gas/power
supplied matches the
gas on the rating plate.
Ex. For Natural Gas (NC250-SV-ASME)
Be sure
to do.
(Continued)
Leave the proper clearance between the
water heater and nearby objects (trees,
timber, boxes with flammable materials etc.).
Left side:
Min. 6" Right side:
Min. 6"
Front:
Sug. 24"*
Be sure
to do.
*Indicates suggested clearances for maintenance.
Do not place the exhaust vent terminal
in an indoor environment by means of
adding walls and ceiling (Do not en-
close using corrugated sheets, etc.)
Carbon monoxide poisoning or fire may
occur as a result.
Exhaust vent
terminal
Unit
Prohibited
Do not use combustible chemicals
such as oil, gasoline, benzene etc.
in the near the heater or the exhaust
vent terminal.
Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
Prohibited
Prohibited
Do not place or use a spray can
near the water heater or the exhaust
vent terminal.
Prohibited
[When installing indoors (NC250-SV-ASME)]
Left side:
Min. 6" Right side:
Min. 6"
Upper:
Min. 36"
Front:
Sug. 24"
[When installing outdoors (NC250-SV-ASME)]
Sug. 3" from
vent pipe*
Upper: Min. 12"
NC250-SV-ASME
WARNING
[When installing indoors (NC250-DV-ASME only)]
Left side:
Min. 6" Right side:
Min. 6"
Front:
Sug. 24"*
Sug. 3" from
vent pipe*
Upper: Min. 12"
Do not place combustibles such as
laundry, newspapers, oils etc.
near the heater or the exhaust vent
terminal. Exhaust vent terminal
(indoor installation)
Prohibited
Unit
Do not place outdoors
Rain may enter the unit or the burner
fire may be blown by the wind, caus-
ing malfunction or fire as a result.
Prohibited
Outdoor
air supply
vent
[When installing indoors
(NC250-SV-ASME only)]
Check the air supply
vent for dust or
obstructions.
Be sure
to do.
[NC250-DV-ASME only]
Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.
Be sure
to do.
Flue terminal
Flue
terminal

5
CAUTION
Be sure to electrically ground the
unit.
Keep power cord free of dust.
Ground.
Be sure
to do.
Do not use the water heater for
other than hot water supply, shower
and bath.
Prohibited
(Continued)
Prohibited
Do not cover the water heater and
the exhaust vent terminal, store
trash or debris near it, or in any way
block the flow of fresh air to the unit.
Do not turn off the water heater
while someone is bathing.
Prohibited
Do not use a broken or modified power cord.
Do not bind, bend or stretch power cords.
Do not scratch, modify, or subject them to
impact or force.
Do not touch the exhaust vent pipe and
exhaust vent terminal during or immediately
after operation of the water heater.
Do not install in locations where
excessive dust or debris will be
in the air.
Prohibited
Don’t
touch.
Prohibited
Be sure
to do.
Do not allow small children to play
unsupervised in the bathroom.
Do not allow small children to
bathe unsupervised.
Do not use hair spray or spray
detergent in the vicinity of the
heater.
Do not touch the power
cord with wet hands.
Prohibited
Electric
Shock.
Don’t touch
with a wet
hand.
Prohibited
Contact Noritz before using with
a solar pre-heater.
Contact a qualified service
technician for any necessary
repairs, service or maintenance.
Consult the nearest Noritz agent if
the water heater location needs to
be changed.
Don’t
disassemble
the equipment.
Be sure
to do.
Be sure
to do.
California Proposition 65 lists chemical
substances known to the state to cause
cancer, birth defects, death, serious illness
or other reproductive harm. This product
may contain such substances, be their
origin from fuel combustion (gas, oil) or
components of the product itself.
To prevent burns or scalding, turn
off the power button and wait until
the equipment cools before per-
forming maintenance.
If this unit will be installed in a beauty
salon or other location where hair
spray or aerosols will be used, locate
the unit in a seperate area that is
supplied with fresh air from outdoors.
Prohibited
The gas conversion kit shall be installed by
a qualified service agency in accordance
with the manufacturer’s instructions and all
applicable codes and requirements of the
authority having jurisdiction.
The information in the instructions must be
followed to minimize the risk of fire or
explosion or to prevent property damage,
personal injury, or death. The qualified
service agency is responsible for the proper
installation of this kit. The installation is not
proper and complete until the operation of
the converted appliance is checked as
specified in the manufacturer’s instructions
supplied with the kit.
(NC250-SV-ASME) (NC250-DV-ASME)

6
Important Safety Information-3
CAUTION
Do not drink water that has been inside the
unit for an extended period of time. Do not
drink the first use of hot water from the
unit in the morning.
Clean the filter on the water inlet as
frequently as required by the quality of
your local water.
Keep the area around the unit clean.
If boxes, weeds, cobwebs, cockroaches etc. are in
the vicinity of the unit, damage or fire can result.
Do not install the equipment where the
exhaust will blow on walls or windows.
Problems resulting from scale formation
are not covered by the warranty.
Preventing damage from freezing ( p.17)
Damage can occur from frozen water within the
device and pipes even in warm environments.
Be sure to read below for appropriate measures.
Repairs for damage caused by freezing are not
covered by the warranty.
This unit is only approved for installation
up to 4500 ft. above sea level.
For installations at higher elevations, contact Noritz
America for Instructions.
Check ignition during use and extinction
after use.
Take necessary measures to prevent
freezing of water and leakage of gas when
leaving the unit unused for long periods of
time. ( p.18)
Do not use parts other than those specified
for this equipment.
If it is snowing, check the air inlet, exhaust
gas vent and exhaust vent terminal for
blockage.
Do not disassemble the remote controller.
Do not use benzene, oil or fat detergents
to clean the remote controller.
This may cause deformation.
Do not get the remote controller wet.
Although it is water resistant, too much water can
cause damage.
Do not splash water on the remote
controller. Do not expose the remote
controller to steam.
Do not locate the remote controller near stoves or
ovens, this may cause damage or failure.
If the water supply is in excess of 12 grains
per gallon (200 mg/L) of hardness, acidic or
otherwise impure, treat the water with
approved methods in order to ensure full
warranty coverage.

7
Important Safety Information....................................................................... 2
Contents ........................................................................................................ 7
General Parts
Main Unit.................................................................................................... 8
Remote Controller .................................................................................... 9
Initial Operation ........................................................................................... 10
How to Use
Muting the Remote Controller ................................................................. 11
Setting and Using the Water Heater........................................................ 12
Flow Meter Alarm ...................................................................................... 14
Adjusting the Maximum Output Temperature........................................ 16
Preventing Damage from Freezing ............................................................ 17
Regular Maintenance................................................................................... 19
Troubleshooting .......................................................................................... 21
Follow-up Service ........................................................................................ 26
Specifications .............................................................................................. 28
Contents

8
NC250-SV-ASME (Indoor/Outdoor Wall Mounted, Power Vented Model)
* The above illustration shows an example of installation.
The exact installation configuration may be slightly different.
Main Unit
Flue Collar
Front Cover
Air Inlet
Water Supply Valve
Gas Supply Valve
Water Drain Valve (with Water Filter)
(Inside Water Inlet) (p.20)
Pressure Relief Valve
General Parts
NC250-DV-ASME (Indoor Wall Mounted, Power Vent/Sealed Model)
Flue Collar
Front Cover
Water Drain Valve (with Water Filter)
(Inside Water Inlet) (p.20)
Pressure Relief Valve
Intake pipe
Water Supply Valve
Gas Supply Valve

9
Remote Controller (RC-7649M)
Burner On Indicator
For setting the hot
water temperature,
the flow meter alarm,
and other settings.
Power On/Off Button
For turning the
heater on and off.
Flow Meter Alarm Set Button
For setting the flow
meter alarm.
(p.14 - 15)
Setting Buttons
* Before use, remove the protective sheet from the remote controller surface.
Temperature Setting
(Ex.: 110°F)
Flow Meter Setting
The display will flash
after hitting the flow
meter alarm set button.
(p.15)
Error Code
When this indicator is lit,
the hot water temperature
can be set. (p.12)
What is actually displayed depends on how the water heater is set.
A number will flash if
a failure occurs.
(p.24)
Priority Indicator
When burning, the
indicator is lit.
( p.13 and 15)

10
Initial Operation
Before the first use of your water heater, make the following preparations.
Follow steps 1 through 4.
1Open the water supply valve.
Open a hot water fixture to confirm that
water is available, and then close the
fixture again.
3Open the gas supply valve.
Hot water fixture
2
Turn on the power.
CLOSED
4
OPEN
Do not touch with wet hands.
(Ex. NC250-SV-ASME)

11
The remote controller will emit a sound
when any button is pushed. This sound
can be muted if it is desired.
1
How to Use
Muting the Remote Controller
* Initial factory setting is with sound
Sound
Muted
No sound
after 5 sec.
1Hold the Power On/Off
Button for five seconds.
Tone sounds
after 5 sec.
• The flow meter alarm cannot be muted.
• The high temperature warning tone when setting the unit to 125°F or higher will not emit a sound
when muted.

12
Remote Controller Display
Press the Power
On/Off Button.
How to Use
Setting and Using the Water Heater
Previous set
temperature
(Ex.: 110°F)
The temperature will be
displayed on the remote
control thermostat.
1
2(Starting with the Power Off)
On
On
High Temperature
To prevent scalding:
Flashes for 10 sec
1
DANGER
Hot Water Heater temperatures over 125°F can cause
severe burns instantly or death from scalding.
•Children, disabled and elderly are at the highest risk of being scalded.
Feel water temperature before bathing or showering.
Temperature limiting valves are available, ask professional person.
• When setting the unit to 125°F or higher, the temperature
display will flash for 10 seconds and emit a tone as a high
temperature warning.
•Take caution when using the unit again after setting to 125°F
or higher. Always check the set temperature before use.
• Do not allow anyone to change the water temperature while
hot water is running.

13
4
3Turn on hot
water.
2
Set temperature.
Turn off the hot
water.
(
Always check the
)
temperature setting
before use.
Hot
Cold
Check the indicator lights.
Water temperature
On Off
(°F: )
The temperature settings below are examples. The temperature setting
necessary depends on the usage, the length of piping and the time of year.
*Initial factory setting is 110°F
If fixtures incorporate mixing valves, set the temperature higher than usual.
* For most residential applications, the recommended setting temperature is 120°F or less.
For applications that occasionally require a higher temperature setting, locate the remote controller
in a convenient location.
* Consult local codes for minimum operating temperatures.
100 105 110 115 120 125 130 135 140 145 150 160 170 180
Shower, hot water supply,
etc.
Washing
dishes, etc.
High temperature

14
How to Use
Flow Meter Alarm
3
2,3
1
2
Set temperature.
Press the Power
On/Off Button
Plug the bath drain.
Preparation
(Starting with the power off)
(
Always check
)
temperature setting
before use.
Hot
Cold
On
The temperature will be displayed
on the remote control thermostat.
Previous set temperature
(example:110°F)
On Check the indicator lights.
Water temperature
1

15
100 105 110 115 120
An alarm will sound for ten
seconds when the flow
reaches the set level.
The water will continue to run unless it is
manually turned off. * Initial factory setting: 110°F
Water Temperature
The temperatures settings below are only examples. The
temperature setting necessary will depend on the usage,
the length of piping and the time of year.
(°F: )
Warmer HotWarm
5Turn off the hot
water when the
alarm sounds.
4Turn on hot
water.
3Adjust flow meter
alarm setting.
To set the flow meter alarm:
Press the flow meter alarm set button
(the setting will flash on the display)
and adjust with the setting buttons.
Increase
Decrease
Choose the flow meter alarm setting
from the following options: 10 - 60
(In 5 gallon intervals), 70 - 100 (In
10 gallon intervals), or 990 gallons.
Note:
The alarm will not sound if
it is set for 990 gal.
Note:
The alarm will not
sound if it is set for
990 gal.
On
Flow meter setting will be flashing
(ex. 45 gal.)
*The level can only be adjusted
while the indicator is flashing.
* After ten seconds, the remote
will again display the temperature.
Off
If the flow meter alarm is being used to indicate when a tub is full:
•If any hot water is being used besides what is going into the tub, the alarm will sound before
the tub is full.
•If there was water in the tub before the fill began, or if the water is not shut off manually when
the alarm sounds, the tub may overflow.
•If there was water in the tub before the fill began, the temperature in the tub after it is full may
be different from the temperature setting.
The alarm will sound when
the set level has been
reached. Stop the water.

16
How to Use
Adjusting the Maximum Output Temperature
2
3
1
3
Change the
temperature using
the setting buttons.
Press and hold the flow
meter alarm set button until
a sound is heard (2 sec.).
Up
Down
The upper limit of the hot-water
supply temperature can be
changed to 100°F, 105°F,
110°F, 115°F, 120°F, 125°F,
130°F, 135°F,140°F, 145°F,
150°F, 160°F, 170°F or 180°F.
2
Turn off the
power.
Off
1
Set the Power button to ON when continuing to use
the unit as is. Otherwise, let the unit sit for 30 sec.
4
Tone sounds
after 2 sec.
*When 2 or more units are connected with a
system controller, the upper limit function is
disabled. The full range of temperature
options will be available at all times.

17
*Damage can occur from frozen water within the device and pipes even in warm environments.
Be sure to read below for appropriate measures.
*Repairs for damage caused by freezing are not covered by the warranty.
Freezing cannot be prevented when the power plug is unplugged. Do not remove the power
plug from the wall outlet.
(Freezing will be prevented regardless of whether the operation switch is ON or OFF.)
Take the measures below for extremely cold temperatures*.
(outside temperature including wind chill factor less than -30°F (indoor installation) or
-4°F (outdoor installation)).
This method can protect not only the heater, but also the water supply,
water piping and mixing valves.
1. Turn the unit on with the Power Button on the Remote Controller.
2. Close the gas supply valve.
3. Open a hot water fixture and let it run for approx. 2 minutes, and then
check that the number 11 is flashing on the remote controller display.
* If multiple units are being used, drain two minutes for each unit.
* It is possible that a different number may be displayed on the
remote controller, but as long as it is flashing, you may continue.
4. Partially close the hot water fixture, but keep a small amount of hot water running
(0.1 gal./minute or about 0.2” thick).
* If there is a mixing valve, set it to the highest level.
* When linking multiple units, discharge water equivalent to 0.1 gal./minute per unit.
5. The flow may become unstable from time to time. Check the flow 30 minutes later.
* Remember to set mixing valves and fixtures to their original levels before using the unit again
to prevent scalding.
* If there is still a risk that the unit will freeze, drain the unit as shown on the next page.
0.2" thick
Hot Water Fixture
Preventing Damage from Freezing-1
Freezing is prevented within the device automatically by the freeze-prevention heater
If water will not flow because it is frozen
1. Close the gas and water valves.
2. Turn off the power button.
3. Open the water supply valve from time to time to check whether water is running.
4. When the water is flowing again, check for water leaks from the equipment and piping before using.
If the heater or the piping is frozen, do not use the heater or it may get damaged.
CAUTION
* In normal operation, freezing is prevented within the device automatically unless the outside
temperature without wind is below -30°F (indoor installation) or -4°F (outdoor installation).
* The freeze prevention heaters will not prevent the plumbing external to the unit from freezing.
Protect this plumbing with insulation, heat tape or electric heaters, solenoids, or pipe covers.
If there remains a freezing risk, contact the nearest Noritz agent.

18
1. Close the gas valve.
2. (1) Turn the power on.
(2) Turn and leave open the hot water fixtures for more than 2 minutes and close.
* If multiple units are being used, drain two minutes for each unit.
* An 11 Error Code may appear on the remote controller.
This is not a malfunction of the unit. Do not turn Power ON/OFF Button OFF.
3. Close the water supply valve, disconnect
the electrical power supplied to the unit.
4. Fully open all hot water fixtures.
5. Open all drain plugs and drain the water out
of the unit.
6. When the water is completely drained, replace all drain
plugs and close the hot water fixtures.
If the water heater will not be used for a long period of time,
Drain the water.
Drain the water as follows:
To avoid burns, wait until the equipment cools down before draining the water.
The appliance will remain hot after it is turned off.
High Temperature
Drain water into a bucket to prevent water damage.
Do not touch with wet hands.
Fixture
Fixture
Turning the Unit Back On
1. Check that all drain plugs are inserted.
2. Check that all hot water fixtures are closed.
3. Follow the procedure on p.10 “Initial operation”, steps 1 through 4.
Drain Plugs
Preventing Damage from Freezing-2
CAUTION

19
To prevent burns or scalding, turn off the power button and wait until the
equipment cools before performing maintenance.
Periodic Maintenance
Wipe the outside surface with a wet cloth, then dry the surface. Use a neutral detergent to
clean any stains.
•Do not use benzene, oil or fatty detergents to clean the remote controller;
deformation may occur.
•The remote controller is water resistant but not water proof. Keep it as dry as possible.
Regular Maintenance-1
Periodic Inspection
Check
For laundry, newspaper,
timber, oil, spray cans
and other combustible
materials.
Equipment
Remote Controller
Wipe the surface with a wet cloth.
For abnormal sounds
during operation.
For abnormalities in
external appearance,
discoloration or flaws.
For water leaks from the
equipment and piping.
For dust or debris in
the air inlet.
For dust and soot in
the exhaust vent or
exhaust vent terminal.
For proper operation of
pressure relief valve.
Check
Check
Check
Check
Check
Check
CAUTION
Be sure to do.
(Ex. NC250-SV-ASME)

20
Periodic Maintenance
If the water drain valve (with water filter) is covered with debris, the hot water may not run
smoothly, or the unit may put out cold water. Check and clean the filter as explained below.
* To avoid burns, wait until the equipment cools down before draining the water.
The appliance will remain hot after it is turned off.
Water Drain Valve (with Water Filter)
1. Close the water supply valve.
2. Open all hot water fixtures.
3. With a bucket ready, remove the inlet and outlet
drain plugs (about 0.3 gal. will drain out)
4. Take the water drain valve (with water filter) out
of the inlet. (See illustration to right).
5. Clean the water drain valve (with water filter) with
a brush under running water.
6. Replace the water drain valve (with water filter)
and close the drain plugs.
(Take care not to lose the packing.)
7. Close all hot water fixtures.
8. Open the water supply valve and check that
water does not leak from the drain plugs or water
drain valve (with water filter). Water Supply
Valve
Inlet
Packing
Water drain valve
(with water filter)
Optional Maintenance
* Isolation Valves may be purchased as an
accessory from Noritz.
They allow for full diagnostic testing and easy
flushing of the system.
*The kit includes two full port isolation valves
and a pressure relief valve for the hot side.
Contact Noritz for more information.
Isolation Valves
Regular Maintenance-2
Water Intlet
Water Outlet
Drain
Hot Water
Service Valve
Pressure Relief Valve Cold Water
Service Valve
(Ex. NC250-SV-ASME)
(Ex. NC250-SV-ASME)