Navien NHW700 User manual

800.519.8794 www.navieninc.com
20 Goodyear lrvine, CA 92618
Installation Manual
NHW700 Non-Condensing Water Heaters
TANKLESS WATER HEATERS · BOILERS
Version: 1.0 (June, 2023)
Getting Service
If your water heater requires service:
●All repairs require pre-authorization by Technical Support.
●Request for your installer or any licensed professional to contact Technical Support at
1-800-519-8794 Option 2 once at the installation site.
●A short list of independent service providers in your area can be found on the website:
www.navieninc.com/installers.
●Contact a licensed professional for the affected system (for example, a plumber, gas fitter,
or electrician).
When you contact Technical Support, please have the following information at hand:
●Model number
●Serial number
●Date purchased
●Installation location and type
●Error code, if any appears on the front panel display

Model
NHW700-160AI/180AI/199AI
NHW700-160AE/180AE/199AE
ALWAYS read and follow this manual completely before using
the water heater. Save for future reference.
Tested and Certified to NSF/ANSI 372 for lead free* compliance.
* The wetted surface of this product contacted by consumable
water contains less than one quarter of one percent (0.25%) of
lead by weight.
Installation Manual
NHW700 Non-Condensing Water Heaters
* Lead Fr
ee
WARNING
If the information in these instructions is not followed exactly, a fire or explosion may
result, causing property damage, personal injury, or death.
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.
The installation must conform with local codes or, in the absence of local codes, the National Fuel
Gas Code, ANSI Z223.1/NFPA 54.
When applicable, the installation must conform with the Manufactured Home Construction and
Safety Standard,Title 24 CFR, Part 3280.
Do not install this water heater in a recreational vehicle, trailer, boat or other moving vehicles as it
will result in a Carbon Monoxide Poisoning Hazard.

2Contents
6. Appendixes 58
6.1 Covering the Clamps with Front Cover
Cap (for NSF 5 Use Only) 58
6.2 Technical Data 59
6.3 Wiring Diagram 61
6.4 Ladder Diagram 62
6.5 Component Assembly Diagrams and
Parts Lists 63
6.6 Installation Check list 75
6.7 Navien HAir Add-on Controller Kit
(Optional) 77
6.8 Requirements for the State of
Massachusetts 78
7. LIMITED WARRANTY NAVIEN, INC. 79
1. Important Safety Information 3
2. About the Water Heater 6
2.1 Included Items 6
2.2 Accessories 6
2.3 Specifications 7
2.4 The Front Panel 8
2.5 Components 9
2.6 Dimensions 11
2.7 Rating Plate 13
3. Installing the Water Heater 14
3.1 Choosing an Installation Location 14
3.2 Mounting the Water Heater to the Wall 18
3.3 Connecting the Gas Supply 19
3.4 Connecting the Water Supply 25
3.5 Venting the Water Heater (Indoor Models
Only) 34
3.6 Connecting the Power Supply 45
3.7 Setting the DIP Switches 46
4. Configuring the Remote Controller
System 49
4.1 Included Items 49
4.2 Connecting the Extension Cable 49
4.3 Attaching the Wall Mounting Bracket 49
4.4 Remote Controller 50
4.5 Multi Remote Controller System 51
4.6 Entering Lock Mode 53
4.7 Setting the Clock 53
4.8 Setting the Recirculation Timer 54
4.9 Starting Recirculation 55
4.10 Canceling all Timer Settings 55
5. Installing a Cascade System 56
5.1 Connecting Water Supplies 56
5.2 Connecting the Communication Cables 57
Contents
Product Installation Information
Model
Date Purchased
Gas Type
Serial Number

3Important Safety Information
The following Safety Alert Symbols are used
in this manual. They are used to alert you
to potential personal injury hazards. Obey
all safety messages that follow this symbol to avoid
possible serious injury or death. This Safety Alert
Symbol precedes any safety message about risk of
personal injury. It may also be accompanied by one
of the following signal words.
If the information in these instructions is not
followed exactly, a fire or explosion may result,
causing property damage, personal injury or death.
DANGER
Indicates a hazardous situation that if not
avoided will result in death or serious injury.
WARNING
Indicates a hazardous situation that if not
avoided could result in death or serious injury.
CAUTION
Indicates a potentially hazardous situation that
if not avoided could result in minor or moderate
injury.
NOTICE
Indicates information considered important but
not hazard-related (such as property damage).
DANGER
If you smell gas:
●Do not try to light any appliance.
●Do not touch any electrical switches or use
landline phones.
●From a neighbor’s phone, call your gas
provider and follow their instructions.
●If you cannot reach your gas provider, call the
fire department.
Do not use or store flammable products,
such as gasoline, solvents, or adhesives in
the same room or area as the water heater.
●The water heater has a main burner flame
that can turn on at any time and can ignite
flammable vapors. Vapors from flammable
liquids can explode and catch fire, causing
death or severe burns.
●Vapors cannot be seen and are heavier than
air. They can travel long distances along the
ground and can be carried from other rooms
to the water heater’s main burner flame by air
current.
●Keep all flammable products far away from
the water heater and store them in approved
containers. Keep the containers closed tightly
and out of the reach of children and pets.
1. Important Safety Information

4Important Safety Information
California law requires the following Prop 65
warning to be provided:
WARNING
Cancer and Reproductive Harm -
www.P65Warnings.ca.gov
WARNING
To prevent death, serious injury, or property
damage:
●Do not turn on the water heater unless the
water and gas supplies are fully opened.
Doing so may damage the water heater.
●Do not turn on the water if the cold water
supply shut-off valve is closed.
Doing so may damage the water heater.
●Do not use this water heater for anything
other than its intended purpose, as
described in this manual.
●When servicing the controls, label all wires
prior to disconnecting them.
Failure to do so may result in wiring errors,
which can lead to improper or dangerous
operation. Verify proper operation after
servicing.
●Do not use unapproved replacement or
accessory parts.
Doing so may result in improper or dangerous
operation and will void the manufacturer’s
warranty.
●Do not place anything in or around the
vent terminals, such as a clothes line, that
could obstruct the air flow in or out of the
water heater.
●This water heater has been approved for
use in the USA only.
Using the water heater in any other country
will void the manufacturer’s warranty.
WARNING
To prevent death, serious injury, or property
damage:
●Do not store or use gasoline or other
flammable liquids near this water heater.
Doing so may result in fire or explosion.
●Do not place combustibles, such as
newspapers or laundry, near the water
heater or venting system.
Doing so may result in a fire.
●Do not place or use hair sprays, spray
paints, or any other compressed gases
near the water heater or venting system,
including the vent termination.
Doing so may result in fire or explosion.
●Do not remove the front cover unless the
power to the water heater is turned off or
disconnected.
Failure to do so may result in electric shock.
●Do not operate the water heater with the
front cover opened.
Doing so may result in fire or carbon
monoxide (CO) poisoning, which may result
in property damage, personal injury, or death.
●Do not operate this water heater without
proper venting.
Doing so may result in fire or carbon
monoxide (CO) poisoning, which may result
in property damage, personal injury, or death.
●Do not touch the power cord or internal
components of the water heater with wet
hands.
Doing so may result in electric shock.