Rinnai Energysaver ES38 Quick start guide

— 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.
WARNING:If the information in these instructions is not
followed exactly, a fire or explosion may result causing
property damage, personal injury or loss of life.
Owner’s Operation and Installation Manual for the
ES38 (RHFE-1004FTA)
Energysaver ®
Gas Direct Vent Wall Furnace
INSTALLER: Leave this manual with the appliance.
CONSUMER: Retain this manual for future reference.
Table of Contents........................ 2
Consumer Safety Information ..... 3
Specifications.............................. 4
Operating Instructions................. 6
Installation Instructions ............. 15
Consumer Support.................... 45
State Regulations...................... 47
French Version.......................... 48
Register your product at www.rinnairegistration.com
or call 1-866-RINNAI1 (746-6241)

2 Rinnai Corporation ES38 Manual
This appliance may be installed in an aftermarket, permanently located, manufactured home
(USA only) or mobile home, where not prohibited by local codes.
This appliance is only for use with the type of gas indicated on the rating plate. This appliance
is not convertible for use with other gases, unless a certified kit is used.
Table of Contents
This appliance may be installed as an OEM installation in a manufactured home (USA only) or
mobile home and must be installed in accordance with the manufacturer’s instructions and the
Manufactured Home construction and Safety Standard, Title 24 CFR, Part 3280, in the United
States, or the Mobile Home Standard, CAN/CSA Z240 MH Series, in Canada.
Consumer Safety Information
Safety Definitions............................................. 3
Safety Behaviors and Practices....................... 3
Safety Features................................................ 4
Specifications
Appliance Specifications..............................4, 5
Features...........................................................5
Flue Manifolds.................................................. 5
Operating Instructions
Getting to Know your New Heating Appliance 6
Control Panel................................................... 7
On / Off.............................................................7
Child Lock ........................................................7
Setting the Clock..............................................8
Operating the Heater Manually........................8
Setting and Operating the Timers....................8
Override Function ............................................9
Economy (Energy Saving Mode).....................9
Set Back.........................................................10
Humidifier and Air Flow Direction ..................10
Care and Maintenance...................................11
Before Making a Service Call.........................12
Fault Codes....................................................13
Restart Function.............................................14
Troubleshooting .............................................14
Installation Instructions
General Instructions....................................... 15
Gas Connection............................................. 16
Clearances to Combustibles.......................... 16
Flue Terminal Clearances ....................... 17, 18
Dimensions.................................................... 19
Installation Parts ........................................... 20
Drilling Flue Hole ........................................... 21
Attach Wall Brackets...................................... 21
Attach Back Spacers ..................................... 21
Flue Manifold Installation......................... 22, 23
Extension Kit Installation ..........................24-26
Connecting the Appliance.............................. 27
Adjust Gas Pressure Settings.................. 28, 29
Operating Instructions ................................... 30
Cut-Away Diagram......................................... 31
Wiring Diagram.............................................. 32
Ladder Diagram............................................. 33
Parts List...................................................34-44
Consumer Support
Warranty Information..................................... 45
Limited Warranty...................................... 45, 46
State Regulations.............................................. 47

Rinnai Corporation ES38 Manual 3
WARNING
CAUTION
Safety Behavior and Practices
• Do not block the warm air discharge. Do not allow
anyone to sleep directly in front of the appliance.
• Due to high temperatures, the appliance should be
located out of traffic and away from furniture and
draperies.
• Children and adults should be alerted to the hazards
of high surface temperature and should stay away
to avoid burns or clothing ignition.
• Young children should be carefully supervised when
they are in the same room as the appliance.
• Clothing or other flammable material should not be
placed on or near the appliance.
• Any safety screen or guard removed for servicing
must be replaced prior to operating the appliance.
• Do not insert items into the louvers.
• Do not spray aerosols near the appliance while it is
operating. Most aerosols contain butane gas which
is flammable.
• Do not unplug the appliance while it is operating or
while the fans are on.
• Do not use bare hands to touch the front louvers
due to high temperatures which may cause burns.
• Wear hand protection when touching the side back
covers, front louver, and rear intake for the
convection fan.
• Prevent dust from accumulating on the power cord,
side covers, and parts behind the appliance.
• Do not sit on the heater.
• Do not place containers of liquid on top of the
heater. Water spillage can cause extensive
damage to the appliance and may result in electric
shock.
• Repairs should be performed by a qualified service
technician.
• Keep the area around the appliance clear and free
from combustible materials, gasoline, and other
flammable vapors and liquids.
• Never store liquid propane containers indoors.
• Do not use this appliance if any part has been under
water. Immediately call a qualified service
technician to inspect the appliance and to replace
any part of the control system and any gas control
which has been under water.
• This appliance is equipped with a three-prong plug
for your protection against shock hazard and should
be plugged directly into a properly grounded three-
prong receptacle. Do not cut or remove the ground
prong from this plug.
• Any alteration to the appliance or its controls can be
dangerous.
• Do not operate appliance with the panels removed,
cracked or broken. Replacement of the panels
should be done by a licensed or qualified service
person.
Consumer Safety Information
Safety Definitions
This is the safety alert symbol. This symbol alerts you to potential hazards that can kill or hurt you and
others.
Indicates an imminently hazardous situation which, if not avoided, will result in death or
serious injury.
Indicates a potentially hazardous situation which, if not avoided, could result in death or
serious injury.
Indicates a potentially hazardous situation which, if not avoided, could result in minor or
moderate injury. It may also be used to alert against unsafe practices.
DANGER
CAUTION
WARNING

4 Rinnai Corporation ES38 Manual
Application For manufactured home (USA only) or mobile home or residential installation
convertible for use with natural gas and liquefied petroleum gases (propane /
LPG) when provision is made for the simple conversion from one gas to the
other.
For commercial setting.
For installation at altitudes up to 10,200 feet (3109 m).
General Description Forced combustion, forced convection, flued gas furnace
Operation Push button electronic
Gas Connection 1/2 in NPT
Gas Control Electronic
Burners Stainless steel Bunsen burner
Temperature Control Electronic thermostat
Ignition System Electronic spark ignition
Flue System The flue must be terminated to atmosphere with only flue components listed
with the appliance’s certification. Warranty will be voided if non listed
components are installed.
Humidifier Tray Capacity - 6.3 pints (3000 cc)
Electrical Connection AC 120V, 60 Hz, 121 watts
Weight 90 lbs (41 kg)
Noise Level 37-47 dB
AFUE Rating Natural Gas: 80.6% Propane: 82.0%
Specifications
Rinnai is continually updating and improving products. Therefore, specifications are subject to change without
prior notice.
The efficiency rating of this appliance is a product thermal efficiency rating determined under continuous operating
conditions and was determined independently of any installed system.
Safety Features
• Overheat: The appliance will automatically shut
down when the appliance exceeds a predetermined
temperature.
• Flame Failure: The appliance will automatically
shut down if the burner flame is extinguished.
• Power Failure: The appliance will cut off the gas if
it loses electrical power.
• Power Surge Fuse: A glass fuse on the PC board
protects against overcurrent. If the fuse blows then
all indicator lamps will be off.
• Spark Detector: The appliance automatically shuts
down if there is an abnormal spark at ignition.
• Fusible Link: In case the overheat feature
prevents the temperature from rising then the fusible
link will break shutting off the appliance.
Appliance Specifications

Rinnai Corporation ES38 Manual 5
Features
Appliance Specifications
The following flue manifold sizes are
available for different wall thicknesses: Name Kit No. fits walls
S Vent Kit FOT-150 3 - 4 1/2 in (75 - 115 mm)
A Vent Kit FOT-151 4 1/2 - 9 1/2 in (115 - 240 mm)
B Vent Kit FOT-152 9 1/2 - 15 3/4 in (240 - 400mm)
C Vent Kit FOT-153 15 3/4 - 23 5/8 in (400 - 600 mm)
D Vent Kit FOT-154 23 5/8 - 31 1/2 in (600 - 800 mm)
Natural Gas Propane Gas
Minimum supply gas pressure 5.0 in (127 mm) W.C. 11.0 in (280 mm) W.C.
Maximum supply gas pressure 10.5 in (267 mm) W.C. 13.0 in (330 mm) W.C.
BTU/hour input Low 10,500 High 38,400 Low 10,500 High 36,500
BTU/hour output Low 8,400 High 30,720 Low 8,400 High 29,200
Flue Manifolds
• Restarts automatically when ignition or combustion
fails.
• Clean Heating Forced Flue Type
• Easy Operation One-Touch Ignition
• Sensible Temperature Control Feature
• Programmable Thermostat
• Warm Air Outlet at Floor Level (keeps your feet
warm)
• Child Lock
• Room Temperature Setting Memory
• Clean the Air Filter - Indicator Lamp
• Energy Saving Economy Setting
• Humidifier Tray
• Air Flow Directional Louvers
• Direct Vent Easily Installed
• Proportional Heating Variable Capacity
• Hush! Quiet Operation
• Modern Design Minimizes Floor Space
Requirements
• Fault Code Message Display
• Timers 1 and 2
• Set back (setting a minimum temperature)
Vent A Kit is included with
the appliance.

6 Rinnai Corporation ES38 Manual
Getting to know your New Heating Appliance
Operating Instructions

Rinnai Corporation ES38 Manual 7
Control PanelControl Panel
Sensible Temperature Control
Child Lock
This feature locks the buttons to prevent unintended operation.
Press the up and down buttons to activate and the lamp will glow. Pressing and
holding the up and down buttons for two seconds will disengage the Lock.
If the Lock is engaged while the unit is operating, all buttons will be disabled except
for the ON/OFF button.
If the Lock is engaged while the unit is off, then all buttons will be disabled. The
Lock must be disengaged in order to turn the unit on.
The sensible temperature control feature allows
comfortable heating which matches the conditions in
the room.
Based on the information collected by the room
temperature thermistor when the heating starts, the
heating capacity is automatically adjusted to achieve a
comfortable heating effect and to reach the
temperature setting quickly.
Occasionally, the room temperature may briefly exceed
the temperature setting due to the layout of the room or
heating area.
On / Off
When you press and release the ON/OFF button, the Temperature Level lamps will illuminate,
the combustion fan will begin to run, and the spark will ignite the main burner.
This heater has an automatic ignition system. When the main burner has lit, the combustion
lamp will glow red, and the spark will stop.
If ignition does not occur, the appliance will automatically turn off and the Temperature Level
lamps will flash indicating a fault code. This may occur when using the appliance for the first time
or if it has not been used for a while. Try operating the appliance again.
To turn the heater off, press the ON/OFF button. The fan will continue to operate for several
minutes after the burner has gone out in order to cool the heater. Do not unplug the heater while
the fan is running.
ON/OFF
Child Lock
Tem p
Time
Clock
Timer 1
Timer 2
on o ff
Timer 1 Timer 2
EconomyOverride
AM
P M
Set Room
Child Lock
Temp
Time
Set back
Set Times ON/OFF
Filter Lamp
If the filter lamp flashes during operation, check the air filter for dust. If dust is
present, clean the filter. See the Care and Maintenance section. Turn the heater off
before cleaning the filter.
Fi l t er
ON

8 Rinnai Corporation ES38 Manual
Operating the Heater Manually
Setting the Clock
1. Press the “Set Times” button.
2. The light next to “Clock” should be lit. Press the up and
down arrows to set the time. Holding down either of the
arrow keys will change the time more quickly.
3. Press the “Set Times” button until none of the time options
are lit up.
Setting and Operating the Timers
Confirm the clock is correct.
NOTE: The clock will have to be reset in
case of a power failure. However the timers
will retain their settings.
The heater will start before the programmed
starting time in order to heat the room by the
programmed starting time.
The timers can be set while the heater is on
or off. To operate the timer, the heater must
be on.
Setting the timers:
1. Press the “Set Times” button twice to set Timer 1.
2. The light next to “Timer 1 on” should be lit. Press the up or down arrows to set the start time. Holding down
either of the arrow keys will change the time more quickly.
3. Press the “Set Times” button again so that the Timer 1 off position is lit. Press the up or down arrows to set
the end time. Holding down either of the arrow keys will change the time more quickly.
4. Press the “Set Times” button again to set the times for Timer 2. Follow the same steps above to set the start
and end times.
5. Press the “Set Times” button until none of the time options are lit up.
Operating the timers:
To operate the heater using a Timer, press the ON/OFF button and the appropriate Timer button. The heater will
operate from the start to end times you have entered for that Timer. It will operate at the temperature setting that
has been set for the heater. The timer can be set while the heater is operating.
1. Turn the heater on by pressing the “ON/OFF” button.
2. Press the up or down arrows to set the temperature. The left display shows
the temperature setting. The right display shows the room temperature.
The thermostat automatically modulates the burner and the fan to maintain the
temperature setting.
The temperature settings available are:
• LO - burner is on minimum combustion
• 60° F - 80° F in two degree increments
• HI - burner is on maximum combustion
Clock
Timer 1
Timer 2
on o ff
Set Times
AM
P M
Set Room
Tem p
Time
ON/OFF
AM
P M
Set Room
Tem p
Time
Clock
Timer 1
Timer 2
on o f
f
Timer 1 Timer 2 AM
P M
Set Room
Te m p
Time Set Times

Rinnai Corporation ES38 Manual 9
Override Function
This function is used only when the heater is in Timer
operation.
It allows you to “override” the reset timer setting until
the beginning of the next Timer period.
For example, if the heater is ON, pressing the
“Override” button will turn the heater OFF until the next
period. If the heater is OFF, pressing the “Override”
button will turn the heater ON, and allow you to select
a temperature setting, until the next period. The
heater will remain on until the next timer period or until
the Override function is turned off.
When in override function, pressing the “Override”
button will return the heater to the operation of the
current timer period.
Economy (Energy Saving Mode)
The Economy mode can only be set while the heater
is operating (heating). Once it is set, it will remain in
the system memory until deactivated.
1. To turn the Economy mode on, press the
“Economy” button. The Economy indicator is lit.
• The Economy mode now remains in the system
memory.
• If the appliance is turned off manually, or stops
heating as a result of an OFF timer period, the
“Economy “ indicator will go out.
• Whenever the appliance starts heating again,
the “Economy” indicator will light.
2. To turn the Economy mode off, press the
“Economy” button. The “Economy “ indicator will
go out.
• The Economy mode can only be turned off while
the heater is operating (heating) and when the
“Economy” indicator is lit.
Economy Mode Information
After the room is heated initially, the air temperature
may be dropped to a lower level without affecting
comfort. The Economy Mode reduces the
temperature by 2 ºF, 30 minutes after the room
temperature setting is reached. After another 30
minutes, it reduces the temperature setting by another
2 ºF, effectively saving energy. The room temperature
setting will drop up to a total of 4 ºF.
The Economy Mode will not operate if the heater is
under capacity for the room size.
30 min
2°F reduction
2°F reduction
30 min
Preset Temperature
Override
Economy

10 Rinnai Corporation ES38 Manual
Humidifier and Air Flow Direction
Adjusting Air Flow Direction
The vertical louvers may be adjusted to move the air
flow more to the right or to the left.
Use a screw driver or similar object to bend each
louver to the desired position.
Do not bend repeatedly (no more than 5 times) or else
the louver will break.
The horizontal louvers (which determines the vertical
air flow direction) are fixed and cannot be adjusted.
CAUTION
Do not adjust the air flow
louvers while warm air is
flowing.
Adding Water to the Humidifier
Set Back
This function allows a minimum room temperature to be pre-set, between 38ºF
and 78ºF (in 2ºF increments). This temperature should be set below the room
temperature setting. The default setting is 60ºF. Once the Set back function is
selected the appliance will start heating whenever the room temperature falls
below the selected temperature, regardless of timer or manual settings.
Follow these steps to set and operate the Set back feature:
1. Make sure the heater is turned OFF.
2. Press the “Set back” button. The light above the button will come on.
3. Press the up and down buttons to set the minimum temperature.
When the “Set back” indicator is on, frost protection is operating, and will always
prevent the room temperature from falling below the pre-set minimum
temperature (as long as electric power and gas is supplied).
To turn this feature off, press the “Set back” button.
The unit will retain its ON or OFF setting after a power failure. (Default setting at
the factory is on.)
Access Door
Max. Fill Line
Humidifier Tray
Filler Spout
Do not force door open too far.
Close door during operation.
Pull
To fill the tray, open the door as shown in the diagram
and pour water into the tray using the spout built into
the door. The air will be humidified as it passes over
the water in the tray.
During operation a small amount of condensation is
produced in the flue system and drains into the
humidifier tray.
If the water overflows from the water level hole, then
do not add any more water.
CAUTION
Do not fill the tray while the
appliance is in operation.
Close the door after filling.
The humidifier tray and
surrounding area are hot
when the appliance is on.
Set back
AM
P M
Set Room
Tem p
Time

Rinnai Corporation ES38 Manual 11
Care and Maintenance
Filters
Dirty filters reduce the air flow and the appliance’s
ability to produce heat. The filters should be cleaned
frequently during the heating season. If the filters
become blocked the filter indicator lamp will flash and
the appliance will beep. Eventually the appliance will
turn off and the Temperature Level lamp 14 will light,
indicating a fault code.
To clean the filters, the
appliance should be OFF
and cool. Remove the
filter and clean it using a
soft dry cloth or vacuum.
If the filter is greasy
wash with warm soapy
water, rinse, and dry
completely.
Do not use the appliance without the filters installed.
Maintenance
All maintenance and service are to be performed by a
qualified service technician, preferably one who has
attended Rinnai service training classes on the Direct
Vent products.
The appliance should be inspected annually by a
qualified service technician. More frequent cleaning
may be required due to excessive lint from carpeting,
bedding material, etc. It is imperative that control
compartments, burners, and circulating air passage
ways of the appliance be kept clean.
Any screen or guard removed for servicing the
appliance must be replaced prior to operating the
appliance. Clean as follows:
1. Turn heat off. Allow to cool for one hour.
2. Remove the front panel by removing two screws.
3. Use pressurized air to remove dust from the main
burner, heat exchanger, and fan blades.
4. Use soft dry cloth to wipe cabinet.
Do not use wet cloth or spray cleaners on the burner.
The flue should be inspected annually for blockages or
damage.
Motors are permanently lubricated and do not need
periodic lubrication. Keep fan and motor free of dust
and dirt by cleaning annually.
Verify proper operation after servicing.
When attaching the front panel, take care not to clip or
pinch any electric cords to prevent electric shock.
Visual Inspection of Flame
Check that the burner flames are operating normally.
The flame can be seen through the circular window on
the right side of the heat exchanger assembly.
When operating normally the burner flame should
appear as long, clear, blue, stable, streaks. Yellow
flames or an orange color is abnormal and
maintenance is required.
Care of Exterior
Dampen soft cloth with warm water. Wring water out
well and wipe the unit.
Do not use volatile substances such as benzene or
thinners. They cause fading of the paint and
deformation of the resin.
Snow Accumulation
Keep the area around flue terminal free of snow and
ice. The appliance will not function properly if the
intake air or exhaust is impeded by obstructions.
Refer to the Flue Terminal Clearances. The clearance
in Ref. A should be maintained from any snow
accumulation.
AIR FILTERS
CAUTION
Prevent dust from accumulating on the power cord,
side covers, and parts behind the appliance.

12 Rinnai Corporation ES38 Manual
Before Making a Service Call
Before making a service call please check the following:
At Ignition:
Heater does not operate.
Warm air does not flow when the burner
lights.
Smoke or strange smells are produced
on the first trial light up after installation.
Sharp clicking noises at ignition, or when
unit cuts down on the thermostat, or goes
out.
During Combustion:
Clunking noise when the thermostat
operates.
Unit is not heating room.
Air filter is blocked or the louvers are
blocked or obstructed.
Heater will not re-ignite after overheating.
When the unit is turned off.
Convection fan continues to run after
turning OFF.
Other Points:
Steam is discharged from the flue terminal .
Unit cuts off without apparent reason.
Power Failure.
Is the heater plugged in?
Have the fuses or breaker blown at the fuse box / breaker panel?
Is there a power failure?
Is the air filter blocked?
Is anything blocking the outlet for the hot air?
Is the flue blocked?
The fan is started automatically after a short delay.
This is to allow the heat exchanger to warm up, helping to avoid cold draughts.
This is caused by grease or oil and dust on the heat exchanger and will stop
after a short time.
This is simply expansion noise from the heat exchanger.
This is the sound of the solenoid gas valves opening and closing.
Is the air filter blocked?
Is the set temperature high enough?
Is the warm air outlet blocked by anything?
Are the doors and windows of the room closed?
Was the appliance correctly sized for the space?
Allow heater to cool, clean air filter, operate again.
Even after unit has cooled down, the heater does not ignite again. Repair is
necessary.
Contact a qualified / authorized service provider.
This is to remove the residual heat from the heat exchanger. The fan will stop
when the heater cools down.
High efficiency appliances tend to discharge water vapor on cold days. This
is normal.
Check whether filters are blocked. Dirty filters will cause the heater to overheat.
Switch OFF, then ON again when power is restored to re-set controls.

Rinnai Corporation ES38 Manual 13
Fault Codes
If there is a malfunction the appliance may shut down
as a safety precaution and display a fault code to
assist in diagnosing the problem. The fault code will
flash in the display on the control panel. When making
a service call, this code will assist with diagnosing the
fault.
You may be able to clear the fault code by turning the
heater off and then on again. If the fault code remains
or returns on the next operation, contact Rinnai or your
nearest service agent and arrange for a service call.
[1] If the fusible link needs replacement, it must be done by a qualified service agency. In addition, the cause of
the overheat needs to be determined. The fusible link is a one use safety device that breaks to shut off the
appliance.
[2] Remove any obstructions. The flue needs to be kept clear to expel exhaust gases. If the appliance fails to
operate contact a qualified service agency.
CODE DISPLAYED FAULT REMEDY
11 Ignition Failure
Check that gas is turned ON.
Check that the vent termination is not
blocked.
Refer to the Restart Function explanation.
Service call if repeated.
14 Overheat Clean filter.
Service call if repeated. [1]
16 Room Overheat
Lower room temperature to less than 104°F
(40°C).
31 Room Temperature Sensor
Disconnection (open circuit)
32 Room Temperature Sensor
short circuit
33 Overheat Temperature Sensor
Disconnection (open circuit)
34 Overheat Temperature Sensor
short circuit
49 Sensor Breakdown
53 Sparker Failure
61 Combustion Fan Failure
70 Faulty ON/OFF Switch or
Faulty “Set Back” Switch
71 Faulty Solenoids
72 Faulty Flame Rod
73 Communication Error Turn heater OFF, then ON again.
99 Flue Block
Check around the flue terminal for blockage.
[2]
Service call.

14 Rinnai Corporation ES38 Manual
Troubleshooting
If there is a power failure while the appliance is on, then the appliance wills tart automatically when the power is
restored.
If the appliance fails to ignite, the appliance will attempt ignition after 1 hour. The “Ignition Failure” fault code, 11,
will appear during that hour and disappears after a successful ignition. If ignition fails again, then the fault code
will remain and another attempt to ignite will occur in 1 hour. The fault code is not stored in the fault code history.
If the flame is extinguished during forced combustion then the appliance will attempt ignition after 1 hour. The
“Ignition Failure” fault code, 11, will appear during that hour and disappears after a successful ignition. Forced
combustion takes place for about 15 seconds after ignition. After this time, the temperature control logic controls
the combustion.
If the flame is extinguished (burner combustion failure) while the temperature control logic is operating the
appliance, then the appliance will immediately attempt ignition. No fault code will appear.
In summary, if the ignition fails or the flame is extinguished during forced combustion then the appliance will
attempt to restart after 1 hour. If the flame is extinguished after this period then the appliance will immediately
attempt ignition.
Restart Function
Problem
Remedy
Cause
Not Plugged In
Power Failure
(Initial Installation)
Air In Gas Pipe
Gas Filter Blocked
Miss Ignition
Flue terminal obstructed
Flue manifold not connected
Louver obstructed
Air filter blocked
Gas Escape
Child Lock Set
Gas turned off at meter, tank,
or valve.
Plug In
Push On/Off button to attempt
restart after power is restored.
Purge air
(Installer)
Service Call
Service Call
Clear obstruction
Service Call
Clear obstruction
Clean filter
Service Call
Cancel Child Lock
Turn gas on
No ON indicator Burner doesn’t ignite Unusual combustion Combustion stops during operation Smell of gas Noisy ignition Takes too long to warm the room
ON Timer is set Cancel “ON” Timer or push
override button

Rinnai Corporation ES38 Manual 15
Installation Instructions
• A qualified service technician should install the
appliance and inspect it before use.
• If you move, check the gas type in your new area.
The local gas authority will be able to advise on
local regulations.
• The installation must conform with local codes or, in
the absence of local codes, with the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, or the Natural
Gas and Propane Installation Code, CSA B149.1.
• A manufactured home (USA only) or mobile home
OEM installation must conform with the
Manufactured Home Construction and Safety
Standard, Title 24 CFR, Part 3280, or, when such a
standard is not applicable, the standard for
Manufactured Home Installations, ANSI Z225.1, or
the standard for Gas Equipped Recreational
Vehicles and Mobile Housing, CSA Z240.4.
• The appliance, when installed, must be electrically
grounded in accordance with local codes or, in the
absence of local codes, with the National Electrical
Code, ANSI/NFPA 70, or the Canadian Electrical
Code, CSA C22.1.
• The appliance and its appliance main gas valve
must be disconnected from the gas supply piping
system during any pressure testing of that system at
test pressures in excess of 1/2 psi (3.5 kPa).
• The appliance must be isolated from the gas supply
piping system by closing its equipment shutoff valve
during any pressure testing of the gas supply piping
system at test pressures equal to or less than 1/2
psi (3.5 kPa).
• If the flooring is carpet, tile, or other combustible
material other than wood, then the appliance must
be installed on a metal or wood panel extending the
full width and depth of the appliance.
• This appliance discharges a large volume of warm
air next to the floor. Any particles in the air such as
cigarette smoke could cause discoloration in nylon
carpets containing dyes or vinyl surfaces.
• This appliance is not designed to built in.
• This appliance is only for use with the type of gas
indicated on the rating plate. This appliance is not
convertible for use with other gases unless a
certified kit is used. If conversion of the unit is
needed, conversions must be performed by a
qualified service provider at the owner’s expense.
• This appliance must not be connected to a chimney
flue serving a separate solid-fuel burning appliance.
• Rinnai suggests that a dedicated electrical circuit
with a 120VAC, 60 Hz, 10 amp power source be
used.
• A test plug are provided for testing of manifold
differential pressure. It is located on the modulating
gas valve.
• The appliance should be correctly sized for the
space it is required to heat. It is recommended that
an Industry standard BTU Heat Loss Calculation be
conducted to determine the proper sizing.
• Follow the installations instructions and those in
Care and Maintenance for adequate combustion
and ventilation air.
• The flow of combustion and ventilation air shall not
be obstructed.
• Clearances to
access the
appliance during
servicing are 10
inches (254
mm) from the
sides, 40 inches
(1 m) from the
front, and the
area shown
above the
appliance in the
picture.
General Instructions
WARNING
Do not use substitute materials.
Use only parts certified with the appliance.
If installation is at a location above
2001 ft (610 m), then follow the Adjust
Gas Pressure Settings procedure.
Appliance input ratings are based on
sea level operation and need not be
changed for operation up to 2000 ft
(610 m) elevation.
NOTICE
10"
(254 mm)
3"
(76 mm)
6"
(153 mm)
clearance for
maintenance

16 Rinnai Corporation ES38 Manual
Gas Connection
• The gas supply line shall be gas tight, sized and so
installed as to provide a supply of a gas sufficient to
meet the maximum demand of the heater without
loss of pressure.
• A shut off valve and appliance connector valve
should be installed in the upstream of the gas line to
permit servicing.
• Flexible pipe and any appliance connector valve
used for gas piping shall be types approved by
nationally recognized agencies.
• Any compound used on the threaded joint of the gas
piping shall be a type which resists the action of
liquefied petroleum gas (propane / LPG).
• After completion of gas pipe connections all joints
including the heater must be checked for gas
tightness by means of leak detector solution, soap
and water, or an equivalent nonflammable solution,
as applicable. (Since some leak test solutions,
including soap and water, may cause corrosion or
stress cracking, the piping shall be rinsed with water
after testing, unless it has been determined that the
leak test solution is non-corrosive.)
• Check the gas supply pressure immediately
upstream at a location provided by the gas
company. Supplied gas pressure must be within the
limits shown in the Specifications section.
• Refer to an approved pipe sizing chart if in doubt
about the size of the gas line.
• Install manual gas cut-off valve so that it can be
accessed for easy operation. Do not conceal
manual cut-off valve behind back spacer.
• An elbow is supplied to attach to the gas line if
needed.
Clearances to Combustibles
When determining where to install the appliance the
clearances to combustibles shown in the figure must
be followed. Also refer to the Safety Behaviors and
Practices section.
Rinnai recommends 10” (254 mm) clearance from the
top and on both sides for servicing.
10"(250mm)
0"
2"
(50mm)
2"
(50mm)
40" (1m)
When connecting the gas valve or other gas
components in the gas line, use a backup wrench to
ensure the connection is gas tight.
WARNING
0” (0 mm)
The 40 inch (1 meter) clearance
from the front of the appliance does
not include flooring material or
carpeting that is less than 1.2 inches
(30 mm) in height.
NOTICE

Rinnai Corporation ES38 Manual 17
Flue Terminal Clearances
X
V
AIR SUPPLY INLET VENT TERMINAL AREA WHERE TERMINAL IS NOT PERMITTTED
INSIDE CORNER DE TAIL
FIXED CLOSED
OPERABLE
FIXED CLOSED
OPERABLE
B
B
B
A
J
BM
C
F
B
B
E
D
L
G
A
H
K
I
SNOW
TERMINATION
Clearance in Ref. A also applies to anticipated snow line
This diagram shows the mini- mum clearances from the flue.

18 Rinnai Corporation ES38 Manual
Flue Terminal Clearances
1 A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single
family dwellings and serves both dwellings.
2 Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
∗ For clearances not specified in ANSI Z223.1/NFPA 54 or CSA B149.1, clearances are in accordance with
local installation codes and the requirements of the gas supplier.
Ref Description Canadian Installations US Installations
A
Clearance above grade, veranda,
porch, deck, or balcony. (Take into
account the anticipated snow line)
12 inches (30 cm) 12 inches (30 cm)
B Clearance to window or door that may
be opened 12 inches (30 cm) 9 inches (23 cm)
C Clearance to permanently closed
window * *
D
Vertical clearance to ventilated soffit,
located above the terminal within a
horizontal distance of 2 feet (61 cm)
from the center line of the terminal
* *
E Clearance to unventilated soffit * *
F Clearance to outside corner * *
G Clearance to inside corner 20 inches (50 cm) 20 inches (50 cm)
H
Clearance to each side of center line
extended above meter/regulator
assembly
3 feet (91 cm) within a height
15 feet (4.5 m) above the
meter/regulator assembly
*
I Clearance to service regulator vent
outlet 3 feet (91 cm) *
J
Clearance to nonmechanical air supply
inlet to building or the combustion air
inlet to any other appliance
12 inches (30 cm) 9 inches (23 cm)
K Clearance to a mechanical air supply
inlet 6 feet (1.83 m) 3 feet (91 cm) above if within
10 feet (3 m) horizontally
L
Clearance above paved sidewalk or
paved driveway located on public
property
7 feet (2.13 m) 1*
M Clearance under veranda, porch, deck,
or balcony
12 inches (30 cm) to non-
flammables 2
24 inches (60 cm) to
flammables 2
12 inches (30 cm) to non-
flammables 2
24 inches (60 cm) to
flammables 2

Rinnai Corporation ES38 Manual 19
Dimensions
inches (mm)
14 1/16" (357.5)
12 7/16" (316)
13" (330)
7 7/8" (200) 4 9/16" (116)
36 5/8" (930)
28 7/16" (723)
26 3/8" (670)
15 5/8" (397)
11 13/16" (300)
GAS CONNECTION
10 7/8"
(R277)
9 13/16" (250)
6 1/2" (165)
6 5/16"(160)
13 3/4" (R350)
Cavi t y Op en in g
23 3/8" (593)

20 Rinnai Corporation ES38 Manual
Installation Parts
The following items are included with the appliance: