State Water Heaters Tankless On-Demand 705 Series 200 Specification sheet

— 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 death.
Operation and Installation Manual
INSTALLER: Leave this manual with the appliance.
CONSUMER: Retain this manual for future reference.
Table of Contents ....................2
Consumer Safety Information ..4
Operating Instructions.............. 5
Maintenance ............................8
Error Codes .............................9
Installation Instructions ............13
Warranty ..................................38
Direct Vent Tankless Water Heater
ANS Z21.10.3
●
CSA 4.3
FOR INDOOR APPLICATIONS ONLY
Models:
305
505
705
Models 305 and 505 are Energy Star Qualified

2 305, 505, 705 Indoor Manual
Specifications ..................................................... 3
Consumer Safety Information
Safety Definitions............................................. 4
Safety Behaviors and Practices....................... 4
Safety Features ............................................... 4
Description of Operation ................................... 5
Operating Instructions
Features Available on Temperature
Controllers ....................................................... 5
Setting the Temperature.................................. 6
Temperature Options Without
a Temperature Controller ................................ 6
Temperature Ranges....................................... 7
Setting Controller to Mute................................ 7
Maintenance
Cleaning ...................................................... 8
Vent System................................................ 8
Motors ......................................................... 8
Temperature Controller............................... 8
Lime / Scale Build-up .................................. 8
Snow Accumulation..................................... 8
Visual Inspection of Flame.......................... 8
Error Codes
Error Code Table ....................................... 9, 10
Trouble Shooting for Common Issues........... 11
Accessing Operating Information .................. 11
Water Quality ................................................. 11
Flushing the Heat Exchanger ........................ 12
(Error Code: LC or 00)
Installation Instructions ................................... 13
General Instructions ...................................... 13
Clearances from Appliance ........................... 14
Attachment of the Water Heater.................... 14
Electrical Connection..................................... 15
Gas Piping
General Instructions ................................ 15
Pipe Sizing Procedure - Example ........... 16
Water Piping
General Instructions ................................ 17
Pressure Relief Valve.............................. 17
Freeze Protection.................................... 17
Freeze Protection Piping ............................... 18
Recommended Piping for Basic Installation.. 19
Recommended Piping for
Circulation Systems....................................... 20
Optional Piping for Circulation Systems........ 21
Venting Instructions
Intake / Exhaust Guidelines .................... 22
Condensate ............................................. 22
Maximum Vent Length ............................ 23
Venting Products ........................................... 24
Flue Terminal Clearances
(ANS Z21.10.3 ●CSA 4.3)............................ 25
Additional Clearances - Vent Terminal.......... 26
Flue Installation for 305 and 505 Models...... 27
Flue Installation for 705 Model ................ 28, 29
High Altitude Installation ................................ 30
Connecting Multiple Water Heaters............... 30
Temperature Controller Installation
Location ................................................... 31
Configurations ......................................... 31
Cable Lengths and Size .......................... 31
Mounting the Controller ........................... 32
Operating Instructions ................................... 33
Technical Data
Pressure Drop Curve..................................... 34
Outlet Flow Data............................................ 34
Space Heating ............................................... 35
Dimensions .................................................... 36
Ladder Diagram............................................. 37
Warranty ...................................................... 38, 39
Table of Contents

305, 505, 705 Indoor Manual 3
Specifications
Specifications are subject to change without prior notice.
The maximum inlet gas pressure must not exceed the value specified by the manufacturer. The minimum value
listed is for the purpose of input adjustment.
* Minimum flow may vary slightly depending on the temperature setting and the inlet water temperature.
** for commercial and hydronic applications requiring higher temperatures
Model 305 505 705
Minimum Gas Consumption Btu/h 15,000 19,000
Maximum Gas Consumption Btu/h 180,000 199,000 Natural Gas
190,000 Propane Gas 237,000
Hot water capacity (Min - Max) * 0.6 - 7.5 GPM
(2.3 - 28.4 L/min)
0.6 - 9.4 GPM
(2.3 - 35.5 L/min)
0.6 - 9.8 GPM
(2.3 - 37 L/min)
Hot water capacity (45°F rise) 6.6 GPM (25.0 L/min)
7.4 GPM (28.0 L/min)
Natural Gas
7.1 GPM (26.9 L/min)
Propane Gas
8.8 GPM (33.5 L/min)
Default Temperature Setting (no controller) 120º F (49º C)
Temperature Controller Default Setting 104º F (40º C)
Maximum Temp Setting (Commercial) ** 160º F (71º C) 185º F (85º C)
Maximum Temp Setting (Residential) Selectable at 120º F (49º C) or at 140º F (60º C) 140º F (60º C)
Minimum Temperature Setting 98º F (37º C)
Weight 50 lb (23 kg) 55 lb (25 kg)
Efficiency Rating 84%
Noise level 49 dB
Electrical Consumption
Normal 65 W 79 W 99 W
Standby
Anti-frost Protection 100 W 116 W
By-Pass Control Fixed Electronic
Minimum Gas Supply
Pressure
Natural Gas 5.0 inch W.C.
Propane 8.0 inch W.C.
Maximum Gas Supply
Pressure
Natural Gas 10.5 inch W.C.
Propane 13.5 inch W.C.
Type of Appliance Direct Vent, Temperature controlled continuous flow gas hot water system.
Operation With or without temperature controls, mounted in kitchen, bathroom, etc.
Approved Gas Type Natural Gas or Propane - Ensure unit matches gas type it's being installed on.
Connections Gas Supply: 3/4" MNPT, Cold Water Inlet: 3/4" MNPT, Hot Water Outlet: 3/4" MNPT
Ignition System Direct Electronic Ignition
Electric Connections Appliance: AC 120 Volts, 60Hz. Temperature Control: DC 12 Volts (Digital)
Water Temperature Control Simulation Feedforward and Feedback.
Water Supply Pressure Minimum Water Pressure: 20 PSI (Recommended 30-80 PSI for maximum performance)
Maximum Water Supply Pressure 150 PSI
Temperature Control Cable Non-Polarized Two Core Cable (Minimum 22 AWG)
Energy Star Qualified Yes Yes No
2 W

4 305, 505, 705 Indoor Manual
WARNING
Safety Behavior and Practices
• Keep the area around the appliance clear and free
from combustible materials, gasoline, and other
flammable vapors and liquids.
• 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 and will void the warranty.
• Always check the water temperature before entering
a shower or bath.
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
Consumer Safety Information
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 protects against
overcurrent. If the fuse blows then all indicator
lamps will be off.
• Fusible Link: In case the overheat feature does
not prevent the temperature from rising then the
fusible link will break shutting off the appliance.

305, 505, 705 Indoor Manual 5
This appliance is one of the most advanced water
heaters available. It provides a continuous supply of
hot water at a preset temperature. This appliance is
direct vent where air is brought in from the outside and
combustion gases are exhausted to the outside.
While electricity, water, and gas supplies are
connected, this appliance produces hot water
whenever a hot water tap is open.
Ignition is electronic. There is no pilot light consuming
gas while the water heater is not being used. The gas
burner lights automatically when the hot water tap is
opened and goes out when the tap is closed.
Installation of the temperature controller is highly
recommended. The temperature controller can set the
temperature within a specific range and can provide
error codes to diagnose any problems.
The temperature of the outgoing hot water is constantly
monitored. This appliance may adjust the water flow in
order to maintain the temperature setting. The water
flow may vary from summer to winter due to the
difference in ground water temperature.
Description of Operation
Features Available on Temperature Controllers
The temperature controller is supplied with the appliance. Dimensions (inches): 3.5 W x 4.75 H x 0.75 D
Operating Instructions
Features Description
Error Codes When a fault is detected an error code flashes at the temperature
In Use Indicator Indicates that hot water is being supplied (i.e. a hot water tap is
open).
On/Off Button Used to turn the water heater On or Off.
Priority Button /
Indicator
Indicates that this controller is setting the temperature . Priority
can be switched to another controller by pressing its Priority
Button when no hot water is running.
Temperature Display Shows the temperature setting.
Thermostat Increases or decreases the temperature setting.
Temperature
Display
Priority
Indicator
Priority
Button
On/Off
Button
In Use
Indicator
Temperature
Selection

6 305, 505, 705 Indoor Manual
Setting the Temperature
1. Press the “Priority button” on the
temperature controller. The
green Priority light will glow
indicating that this controller is
controlling the temperature and
that the water heater is ready to
supply hot water.
While any hot water is being
provided, the temperature setting can
only be adjusted between 98º F and
110º F.
NOTICE
DANGER Hot water can be dangerous, especially for infants or children, the elderly,
or infirm. There is hot water scald potential if the thermostat is set too high.
Water temperatures over 125º F (51º C) can cause severe burns or
scalding resulting in death.
Hot water can cause first degree burns with exposure for as little as:
3 seconds at 140º F (60º C)
20 seconds at 130º F (54º C)
8 minutes at 120º F (48º C)
Test the temperature of the water before placing a child in the bath or
shower.
Do not leave a child or an infirm person in the bath unsupervised.
The priority can only be changed
while no hot water is running.
Temperature Options Without a Temperature Controller
The default temperature setting for this appliance
installed without a temperature controller is 120º F
(49º C). If desired the temperature setting can be
changed to 140º F (60º C) by adjustment of a dip
switch.
Set dip switch 5 to ON to obtain 140º F water
temperature setting.
Set dip switch 5 to OFF (default) to obtain 120º F
2. Press the ▲or ▼buttons to
obtain the desired temperature
setting.
All hot water sources are able to
provide water at this temperature
setting until it is changed again at
this or another temperature
controller.
Check local codes for the maximum
water temperature setting allowed
when used in nursing homes,
schools, day care centers, and all
other public applications.
NOTICE
WARNING DO NOT adjust the other dip
switches unless specifically
instructed to do so.
120º F (49º C) 140º F (60º C)
Switch No.
F
O
F
8
5
7
6
4
3
ON
1
2
Switch No.
F
O
F
8
5
7
6
4
3
ON
1
2
If a newly installed unit with a
temperature controller has not been
powered for at least 6 hours then the
temperature will return to the default
setting of 104º F (40º C) if power is
interrupted.
NOTICE
There may be a variation between
the temperature displayed on the
temperature controller and the
temperature at the tap due to
weather conditions or the length of
pipe to the water heater.
NOTICE

305, 505, 705 Indoor Manual 7
Temperature Ranges
This water heater will attempt to provide hot water at the temperature setting even when the water flow is varied
or when more than 1 tap is in use. The water heater can deliver water at only one temperature setting at a time.
The available temperatures for a given model are provided below.
Suggested temperatures are
• Kitchen 120 ºF (49º C)
• Shower 98º - 110º F (37º - 43º C)
These temperatures are suggestions only.
A temperature lower than 98º F (37º C) can be
obtained at the tap by mixing with cold water.
To change the temperature scale from Celsius to Fahrenheit or vice versa, press and hold the “On/Off” button for
5 seconds while the water heater is OFF.
Setting Controller to Mute
To eliminate the beeps when keys are pressed or to turn the beeps back on, press and hold both the ▲and ▼
buttons until a beep is heard (approximately 5 seconds).
The commercial controller is intended for commercial and hydronic applications only. If commercial controller
is used in a residential dwelling for a hydronics application, a mixing valve must also be installed to limit the
potable hot water temperature to a safe temperature. Water temperatures over 125º F (51º C) can cause
severe burns or scalding. Refer to the Danger Alert on water temperatures. The manufacturer shall not, in
any event, be liable for damages resulting from such misuse or misapplication.
** Commercial Controller
These settings require the commercial controller which is for commercial and hydronic applications requiring
higher temperatures. When the commercial controller is connected, these higher temperatures are available
on all controller models in the system.
Model
305 98 100 102 104 106 108 110 115 120 125
*
130
*
135
*
140
*
150
**
160
**
705 98 100 102 104 106 108 110 115 120 125 130 135 140 150
**
160
**
185
**
Temp in Celsius ºC 37 38 39 40 41 42 43 46 49 52 54 57 60 66 71 85
Temperature Settings Available (ºF)
505 98 100 102 104 106 108 110 115 120 125
*
130
*
135
*
140
*
150
**
160
**
185
**
* Re-setting the Maximum Temperature
Models 305 and 505 have a default maximum temperature of 120º F (49º C) and an option to increase the
maximum temperature to 140 ºF (60 ºC). Temperature settings from 125-140 ºF (52-60 ºC) are available by
setting dip switch 6 to ON in the SW1 bank of 8 dip switches.
Model 705 has a default maximum temperature of 140 ºF (60 ºC).

8 305, 505, 705 Indoor Manual
WARNING
Turn off the electrical power supply, the manual gas
valve and the manual water control valve whenever
servicing the unit.
Repairs and maintenance should be performed by a
qualified service technician. The appliance should be
inspected annually by a qualified service technician.
Verify proper operation after servicing.
Cleaning
It is imperative that control compartments, burners,
and circulating air passageways of the appliance be
kept clean.
Clean as follows:
1. Turn off and disconnect electrical power. Allow to
cool.
2. Remove and clean the water inlet filter.
3. Remove the front panel by removing 4 screws.
4. Use pressurized air to remove dust from the main
burner, heat exchanger, and fan blades. Do not
use a wet cloth or spray cleaners on the burner.
Do not use volatile substances such as benzene
and thinners. They may ignite or fade the paint.
5. Use soft dry cloth to wipe cabinet.
Vent System
The vent system should be inspected at least annually
for blockages or damage.
Motors
Motors are permanently lubricated and do not need
periodic lubrication. Keep fan and motor free of dust
and dirt by cleaning annually.
Temperature Controller
Use a soft damp cloth to clean the temperature
controller. Do not use solvents.
Lime / Scale Build-up
If you receive Error Code “LC”, refer to the procedure,
Flushing the Heat Exchanger. Refer to the section on
Water Quality to see if your water needs to be treated
or conditioned. (When checking maintenance code
history, “00” is substituted for “LC”.)
Visual Inspection of Flame
The burner must flame evenly over the entire surface
when operating correctly. The flame must burn with a
clear, blue, stable flame. See the parts breakdown of
the burner for the location of the view ports.
The flame pattern should be as shown in the figures
below.
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 (blocked or partially
blocked) by obstructions.
Maintenance

305, 505, 705 Indoor Manual 9
Error Codes
This appliance has the ability to check its own operation continuously. If a fault occurs, an error code will flash on
the Display of the temperature controller. This assists with diagnosing the fault and may enable you to overcome
a problem without a service call. Please identify the code displayed when inquiring about service.
Code Fault Remedy
02 No burner operation during
freeze protection mode
Service Call
10 Air Supply or Exhaust
Blockage
Ensure approved venting materials are being used.
Check that nothing is blocking the flue inlet or exhaust.
Check all vent components for proper connections.
Ensure vent length is within limits.
Ensure condensation collar was installed correctly.
Verify dip switches are set properly.
Check fan for blockage.
11 No Ignition Check that the gas is turned on at the water heater, gas meter, or cylinder.
Ensure gas type and pressure is correct.
Ensure gas line, meter, and/or regulator is sized properly.
Bleed all air from gas lines.
Verify dip switches are set properly.
Ensure appliance is properly grounded.
Disconnect all 2-Unit or Multi-Unit connections to isolate the problem.
Ensure igniter is operational.
Check igniter wiring harness for damage.
Check gas solenoid valves for open or short circuits.
Remove burner cover and ensure all burners are properly seated.
Remove burner plate and inspect burner surface for condensation or debris.
12 Flame Failure Check that the gas is turned on at the water heater and gas meter. Check for
obstructions in the flue outlet.
Ensure gas line, meter, and/or regulator is sized properly.
Ensure gas type and pressure is correct.
Bleed all air from gas lines.
Ensure proper venting material was installed.
Ensure condensation collar was installed properly.
Ensure vent length is within limits.
Verify dip switches are set properly.
Ensure appliance is properly grounded.
Disconnect keypad.
Disconnect all 2-Unit or Multi-Unit connections to isolate the problem.
Check power supply for loose connections.
Check power supply for proper voltage and voltage drops.
Ensure flame rod wire is connected.
Check flame rod for carbon build-up.
Disconnect and reconnect all wiring harnesses on unit and PC board.
Check all components for electrical short.
Check gas solenoid valves for open or short circuits.
Remove burner plate and inspect burner surface for condensation or debris.
Some of the checks below may need to be done by a qualified service technician. Call a
service technician for any remedy that involves gas or electricity. Call a service
technician if you have any doubt or reservation about performing the remedy yourself.
WARNING
Error Code Table

10 305, 505, 705 Indoor Manual
Code Fault Remedy
14 Thermal Fuse Check gas type of unit and ensure it matches gas type being used.
Check for restrictions in air flow around unit and vent terminal.
Check for low water flow in a circulating system causing short-cycling.
Ensure dip switches are set to the proper position.
Check for foreign materials in combustion chamber and/or exhaust piping.
Check heat exchanger for cracks and/or separations.
Check heat exchanger surface for hot spots which indicate blockage due to scale build-
up. Refer to instructions in manual for flushing heat exchanger.
Measure resistance of safety circuit.
Ensure high fire and low fire manifold pressure is correct.
Check for improper conversion of product.
16 Over Temperature
Warning
Check for restrictions in air flow around unit and vent terminal.
Check for low water flow in a circulating system causing short-cycling.
Check for foreign materials in combustion chamber and/or exhaust piping.
Check for clogged heat exchanger.
32 Outgoing Water
Temperature Sensor
Fault
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Replace sensor.
33 Heat Exchanger
Outgoing Temperature
Sensor Fault
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Replace sensor.
34 Combustion Air
Temperature Sensor
Fault
Check for restrictions in air flow around unit and vent terminal.
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Ensure fan blade is tight on motor shaft and is in good condition.
Replace sensor.
52 Modulating Solenoid
Valve Signal Abnormal
Check modulating gas solenoid valve wiring harness for loose or damaged terminals.
Measure resistance of valve coil.
61 Combustion Fan
Failure
Ensure fan will turn freely.
Check wiring harness to motor for damaged and/or loose connections.
Measure resistance of motor winding.
71 SV0, SV1, SV2, and
SV3 Solenoid Valve
Circuit Fault
Check wiring harness to all solenoids for damage and/or loose connections.
Measure resistance of each solenoid valve coil.
72 Flame Sensing Device
Fault
Ensure flame rod is touching flame when unit fires.
Check all wiring to flame rod for damage.
Remove flame rod and check for carbon build-up; clean with sand paper.
Check inside burner chamber for any foreign material blocking flame at flame rod.
Measure micro amp output of sensor circuit with flame present.
Replace flame rod.
LC Scale Build-up in Heat
Exchanger (when
checking maintenance
code history, “00” is
substituted for “LC”)
Flush heat exchanger. Refer to instructions in manual.
Replace heat exchanger.
No
code
Nothing happens when
water flow is activated.
Clean inlet water supply filter.
On new installations ensure hot and cold water lines are not reversed.
Check for bleed over. Isolate unit from building by turning off hot water line to building.
Isolate the circulating system if present. Open your pressure relief valve; if water is
flowing, there is bleed over in your plumbing.
Ensure you have at least the minimum flow rate required to fire unit.
Ensure turbine spins freely.
Measure the resistance of the water flow control sensor.
Check for DC shorts at components.
Error Code Table

305, 505, 705 Indoor Manual 11
Trouble Shooting for Common Issues
I don’t have any hot water when I open the tap.
Make sure there is gas, water, and electricity to the
water heater (power is turned on and the gas is turned
on).
When I was using the hot water, the water got cold.
If you adjusted the flow from the tap to lessen it, you
may have gone below the minimum flow required. This
water heater requires a minimum flow rate to operate.
(See the specification page for the flow rate of your
model.) Decrease the temperature setting at the
temperature controller or increase the water flow.
White smoke comes out of the exhaust.
During colder weather when the exhaust temperature
is much hotter than the outside air, the exhaust fumes
condense producing water vapor.
When I open a hot tap, I do not immediately get hot
water.
Hot water must travel through your plumbing from the
water heater to the faucet. The time period for hot
water to reach your fixture is determined by the amount
of water in the plumbing system between the water
heater and the fixture, water pressure, and the flow
rate of the fixture.
After I turn off the hot water tap, the fan on the
water heater continues to run.
The fan is designed to continue running for a short time
after the flow of water stops. This is to ensure constant
water temperatures during rapid starting and stopping,
as well as exhausting any residual gas flue products
from the unit.
Consideration of care for your water heater should
include evaluation of water quality. If the water quality
exceeds the target levels provided in the table, you
may want to treat or condition the water.
* Source: Part 143 National Secondary Drinking Water
Regulations
Maximum Level
Total Hardness Up to 200 mg / L
Aluminum * Up to 0.2 mg / L
Chlorides * Up to 250 mg / L
Copper * Up to 1.0 mg / L
Iron * Up to 0.3 mg / L
Manganese * Up to 0.05 mg / L
pH * 6.5 to 8.5
TDS (Total Dissolved
Solids) *
Up to 500 mg / L
Zinc * Up to 5 mg / L
WaterQuality
Accessing Operating Information
To display the most recent error codes press and hold the “On/Off” button for 2 seconds. While holding the “On/
Off” button press the ▲button. The last 9 error codes will flash one after the other. To exit this mode press the
“On/Off” and ▲button as before.
To display the water flow through the water heater press and hold the ▲button for 2 seconds and without
releasing the ▲button press the “On/Off” button.
To display the outlet water temperature press and hold the ▼button for 2 seconds and without releasing the ▼
button press the “On/Off” button.

12 305, 505, 705 Indoor Manual
Flushing the Heat Exchanger (Error Code: LC or 00)
An “LC” or “00” error code indicates the unit is beginning to lime up and must be flushed. Failure to flush the
appliance will cause damage to the heat exchanger. Damage caused by lime build-up is not covered by the unit’s
warranty. After flushing, reset the LC fault code by turning off the power to the unit and turning the power back
on.
Water Heater
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
GasSuppl
y
V1
V3
V2
V4
H1
H2
H3
Circulating Pump
5 gallon pail of virgin, food
grade, white vinegar (or virgin,
food grade, citric acid).
ColdWaterLine
HotWaterLine
n-line
Filter
I
1. Disconnect electrical power to the water heater.
2. Close the shutoff valves on both the hot water and cold
water lines (V3 and V4).
3. Connect pump outlet hose (H1) to the cold water line at
service valve V2.
4. Connect drain hose (H3) to service valve V1.
5. Pour approximately 4 gallons of virgin, food grade, white
vinegar or citric acid into pail.
6. Place the drain hose (H3) and the hose (H2) to the pump
inlet into the cleaning solution.
7. Open both service valves (V1 and V2) on the hot water and
cold water lines.
8. Operate the pump and allow the cleaning solution to
circulate through the water heater for at least 45 minutes.
9. Turn off the pump.
10. Rinse the cleaning solution from the water heater as follows:
a. Remove the free end of the drain hose (H3) from the pail.
b. Close service valve, (V2), and open shutoff valve, (V4).
Do not open shutoff valve, (V3).
c. Allow water to flow through the water heater for 5 minutes
d. Close service valve, (V1), and open shutoff valve, (V3).
11. Disconnect all hoses.
12. Remove the in-line filter at the cold water inlet and clean out
any residue. Place filter back into unit.
13. Restore electrical power to the water heater.

305, 505, 705 Indoor Manual 13
Only properly trained and qualified installers should
install this appliance. The warranty may be voided due
to improper installation or installation by a non-qualified
installer.
It is highly recommended that all installers attend a
product knowledge class.
General Instructions
• This appliance must be installed by a state qualified
or licensed contractor. It is the responsibility of the
person having the water heater installed to ensure
the installing contractor has proper licenses and
permits for installing water heaters in your location.
It is highly recommended that installers attend a
product knowledge class to ensure customer
satisfaction and warranty coverage. Failure to
comply with state and local codes pertaining to
water heater installations may void the warranty.
• This appliance is not to be installed outdoors.
• A qualified installer or service technician should
install the appliance, inspect it, and leak test it
before use.
• 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.
• 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) (13.84
in W.C.).
• The appliance must be isolated from the gas supply
piping system by closing its individual manual
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) (13.84 in W.C.).
• Follow the installation instructions and those in Care
and Maintenance for adequate combustion and
ventilation air.
• The appliance should be located in an area where
water leakage of 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 cannot be avoided, it is
recommended that a suitable drain pan, adequately
drained, be installed under the appliance. The pan
must not restrict combustion air flow.
• The flow of combustion and ventilation air shall not
be obstructed.
• This appliance is not suitable for use in an
application such as a pool or spa heater that uses
chemically treated water . (This appliance is
suitable for filling large or whirlpool bath tubs with
potable water.)
• If a water heater is installed in a closed water supply
system, such as one having a backflow preventer in
the cold water supply line, means shall be provided
to control thermal expansion. Contact the water
supplier or local plumbing inspector on how to
control thermal expansion.
• Should overheating occur or the gas supply fail to
shut off, turn off the manual gas control valve to the
appliance.
• Keep the air intake location free of chemicals such
as chlorine or bleach that produce fumes. These
fumes can damage components and reduce the life
of your appliance.
WARNING
Do not use substitute materials.
Use only parts certified with the appliance.
Installation Instructions

14 305, 505, 705 Indoor Manual
Clearances from Appliance
1. Identify the installation location and confirm that
the installation will meet all required clearances.
2. Securely attach the water heater to the wall using
any of the holes in the wall installation brackets
which are at the top and bottom of the water
heater. Ensure that the attachment strength is
sufficient to support the weight. Refer to the
weight of the water heater in the Specifications
section.
Attachment of the Water Heater
wall installation
brackets
to side
to front
to top
to floor/ground
to Combustibles to Non-
Combustibles
305
505 705 305
505 705
Top of
Heater
6 inches
(152 mm)
12 inches
(305 mm)
2 inches
(51 mm)
2 inches
(51 mm)
Back of
Heater
0 (zero) 0 (zero) 0 (zero) 0 (zero)
Front of
Heater
6 inches
(152 mm)
24 inches
(610 mm)
6 inches
(152 mm)
24 inches
(610 mm)
Sides of
Heater
2 inches
(51 mm)
2 inches
(51 mm)
1/2 inch
(13 mm)
1/2 inch
(13 mm)
Floor/
Ground
12 inches
(305 mm)
12 inches
(305 mm)
12 inches
(305 mm)
2 inches
(51 mm)
Vent 0 (zero) 4 inches * 0 (zero) 0 (zero)
* 4 inches (102 mm) for enclosed area; 1 inch (26 mm) for unenclosed area.
The clearance for servicing is 24 inches in front of the water heater.
For closet installation: 305, 505: clearance is 6 inches (152 mm) from the front.
705: clearance is 24 inches (610 mm) from the front.

305, 505, 705 Indoor Manual 15
GasPiping
General Instructions
• A manual gas control valve must be placed in the
gas supply line to the water heater. A union can be
used on the connection above the shut off valve for
the future servicing or disconnection of the unit.
• Check the type of gas and the gas inlet pressure
before connecting the water heater. If the water
heater is not of the gas type that the building is
supplied with, DO NOT connect the water heater.
Contact the dealer for the proper unit to match the
gas type.
• 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.
• Before placing the appliance in operation 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.)
• Always use approved connectors to connect the unit
to the gas line. Always purge the gas line of any
debris before connection to the water heater.
• The gas supply line shall be gas tight, sized, and so
installed as to provide a supply of gas sufficient to
meet the maximum demand of the heater and all
other gas consuming appliances at the location
without loss of pressure.
• 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).
• Refer to an approved pipe sizing chart if in doubt
about the size of the gas line.
Electrical Connection
The water heater requires a standard 3 prong 120 VAC, 60 Hz properly grounded wall outlet. Plug the 6ft long
power cord into the wall outlet.

16 305, 505, 705 Indoor Manual
Pipe Sizing Procedure - Example
1. Determine the cubic feet per hour of gas required by dividing the gas input (on the rating plate) by the heating
value of the gas (available from the local gas company). The gas input needs to include all gas products at
the location and the maximum BTU usage at full load when all gas products are in use.
Gas Input of the water heater (BTU / HR)
Cubic Feet per Hour (CFH) =
Heating Value of Gas (BTU / FT
3 )
2. Use the table for your gas type to find the pipe size required for your cubic feet per hour of gas and your pipe
length.
Example: The heating value of propane gas for your location is 2516 BTU / FT 3.
The gas input is 190,000 BTU/HR. Additional appliances at the location require 75,000 BTU/HR.
Therefore the cubic feet per hour = (190,000+75,000) / 2516 = 105.3 FT 3/ HR.
If the pipe length is 100 ft then the 3/4 inch pipe size capable of supplying 197 FT 3/ HR of propane gas
will be adequate.
Pipe Sizing Table - Natural Gas Pipe Sizing Table - Propane Gas
Pipe Size (inches)
3/4 1 1 1/4 1 1/2
10 273 514 1060 1580
20 188 353 726 1090
30 151 284 583 873
40 129 243 499 747
50 114 215 442 662
60 104 195 400 600
70 95 179 368 552
80 89 167 343 514
90 83 157 322 482
100 79 148 304 455
125 70 131 269 403
150 63 119 244 366
175 58 109 224 336
200 54 102 209 313
Length Length Pipe Size (inches)
1/2 3/4 1 1 1/4
10 291 608 1150 2350
20 200 418 787 1620
30 160 336 632 1300
40 137 287 541 1110
50 122 255 480 985
60 110 231 434 892
80 101 212 400 821
100 94 197 372 763
125 89 185 349 716
150 84 175 330 677
175 74 155 292 600
200 67 140 265 543
Inlet Pressure: less than 2 psi (55 inches W.C.)
Pressure Drop: 0.3 inches W.C.
Specific Gravity: 0.60
Inlet Pressure: 11.0 inches W.C.
Pressure Drop: 0.5 inches W.C.
Specific Gravity: 1.50
Schedule 40 Metallic Pipe
cubic feet per hour Schedule 40 Metallic Pipe
cubic feet per hour
GasPiping
The gas supply must be capable of handling the entire gas load at the location. Gas line sizing is based on gas
type, the pressure drop in the system, the gas pressure supplied, and gas line type. Refer to the National Fuel
Gas Code, NFPA 54, for proper gas line sizing. The below information is provided as an example.

305, 505, 705 Indoor Manual 17
The freeze protection features include electrical
heating elements and intermittent firing of the burner.
Freeze protection may be disabled if electricity or gas
is not supplied, or if there is an error preventing the
water heater from functioning. Loss of freeze
protection may result in water damage from a burst
heat exchanger or water lines.
The installation of auto drain down solenoid valves is
optional. However, it is strongly recommended that
these valves be installed to prevent damage from
freezing in case the normal freeze protection should
become disabled. Any product damage due to
freezing will not be covered by the warranty.
In addition, the solenoid valves should be connected
electrically to a surge protector with terminals that
attaches to the PC board in the unit. This allows the
solenoid valves to operate if the water heater is
disabled due to an error code.
The solenoid valves and the surge protector with
terminals are available for purchase separately.
Freeze Protection
Water Piping
• A manual water control valve must be placed in the
water inlet connection to the water heater before it is
connected to the water line. Unions may be used
on both the hot and cold water lines for future
servicing and disconnection of the unit.
• The piping (including soldering materials) and
components connected to this appliance must be
approved for use in potable water systems.
• Purge the water line to remove all debris and air.
Debris will damage the water heater.
• Toxic chemicals such as those used for boiler water
treatment are not to be introduced to the potable
water used for space heating.
• If the appliance will be used as a potable water
source, it must not be connected to a system that
was previously used with a nonpotable water
heating appliance.
• Ensure that the water filter on the water heater is
clean and installed.
• An approved pressure relief valve is required by the
American National Standard (ANSI Z21.10.3) /
Canadian Standard (CSA 4.3) for all water heating
systems.
• The relief valve must comply with the standard for
Relief Valves and Automatic Gas Shutoff Devices
for Hot Water Supply Systems ANSI Z21.22 and /or
the standard Temperature, Pressure, Temperature
and Pressure Relief Valves and Vacuum Relief
Valves, CAN1-4.4.
• The relief valve must be rated up to 150 psi and to
at least the maximum BTU/hr of the appliance.
• The discharge from the pressure relief valve should
be piped to the ground or into a drain system to
prevent exposure or possible burn hazards to
humans or other plant or animal life. Follow local
codes. Water discharged from the relief valve could
cause severe burns instantly, scalds, or death.
• The pressure relief valve must be manually
operated once a year to check for correct operation.
• The relief valve should be added to the hot water
outlet line according to the manufacturer’s
instructions. DO NOT place any other type valve or
shut off device between the relief valve and the
water heater.
• Do not plug the relief valve and do not install any
reducing fittings or other restrictions in the relief line.
The relief line should allow for complete drainage of
the valve and the line.
• If a relief valve discharges periodically, this may be
due to thermal expansion in a closed water supply
system. Contact the water supplier or local
plumbing inspector on how to correct this situation.
Do not plug the relief valve.
• Neither this water heater nor the American National
Standard (ANSI Z21.10.3) / Canadian Standard
(CSA 4.3) requires a combination temperature and
pressure relief valve for this appliance. However,
local codes may require a combination temperature
and pressure relief valve.
Pressure Relief Valve
General Instructions

18 305, 505, 705 Indoor Manual
Freeze Protection Piping
Warranty does not cover damage due to freezing.
When electrical power and gas are supplied to the
water heater, it will not freeze in environments as cold
as -30º F when protected from direct wind exposure.
In the event of a power failure at temperatures below
freezing the water heater should be drained of all
water to prevent freezing damage.
The unit may be drained manually. However, it is
highly recommended that drain down solenoid valves
be installed that will automatically drain the unit if
power is lost. It is also recommended that a surge
protector with terminals be installed that attaches to
the PC board in the unit and allows the solenoid
valves to operate if the unit is disabled due to an error
code.
When the electrical power to the water heater fails, the
3/4” solenoid valve closes (stopping the flow of water
into the heater) and the 1/2” solenoid valve opens
(allowing the water heater and associated piping to
drain. Ensure that you run the drain for the solenoids
to the outside environment to prevent discharging
water inside the building causing water damage).
NOTICE
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
GasSupply
Minimum3/4"
ColdWater
SupplyLine
Minimum 3/4" Hot Water
Supply Line
S
1/2" Minimum
Normally Open
Solenoid Valve
3/4" Minimum
Normally Closed
Solenoid Valve
Route to Floor Drain
Vacuum
Breaker
NOTE:
ALL pipe and fittings shown below dashed line
should be located inside home or building
structure.
NOTE:
Heat trace ALL water pipe and fittings located
outside home (attic, crawl space) or building
structure. (ALL water pipe and fittings shown
above the dashed line in the drawing.)
Water Heater
3/4"GasConnection
S
The vacuum breaker line should be located
inside the building structure.
This is not an engineered drawing. It is intended only as a guide and not
as a replacement for professionally engineered project drawings. This
drawing is not intended to describe a complete system. It is up to the
contractor/engineer to determine the necessary components and
configuration of the particular system being installed. This drawing does
not imply compliance with local building code requirements. It is the
responsibility of the contractor/engineer to ensure installation is in
accordance with all local building codes. Confer with local building
officials before installation.

305, 505, 705 Indoor Manual 19
Recommended Piping for Basic Installation
GasSupply
3/4"ColdWaterSupplyLine
3/4" Hot Water Supply Line
Equipment List
Water Heaters
Kit (Optional)
(3/4" Fittings Include:
2 Unions, 2 Ball Valves,
2DrainValvesand
1 Pressure Relief Valve.)
QTY
1
1
3/4"GasConnection
For Building Fixtures
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
This is not an engineered drawing. It is intended only as a guide and not
as a replacement for professionally engineered project drawings. This
drawing is not intended to describe a complete system. It is up to the
contractor/engineer to determine the necessary components and
configuration of the particular system being installed. This drawing does
not imply compliance with local building code requirements. It is the
responsibility of the contractor/engineer to ensure installation is in
accordance with all local building codes. Confer with local building
officials before installation.
Plumbing Installation
Water Heater

20 305, 505, 705 Indoor Manual
Recommended Piping for Circulation Systems
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
Minimum 3/4" Cold Water Supply Line
Electric Water
Heater
Building
Fixtures
Building Supply
ExpansionTank
GasSupply
Water Heater
3/4"GasConnection
Tank Water Heater to be Sized for
Heat Loss of Circulation Loop.
For this application:
Pump should be controlled by an Aqua-
stat, Timer or Combination Aquastat and
Timer.
Pump to be sized to maintain circulation
loop temperature.
The pump should be sized to overcome
t
he pressure loss through the tank water
heater, and supply and return plumbing.
Pump to be of bronze or stainless
construction.
This is not an engineered drawing. It is intended only as a guide and not
as a replacement for professionally engineered project drawings. This
drawing is not intended to describe a complete system. It is up to the
contractor/engineer to determine the necessary components and
configuration of the particular system being installed. This drawing does
not imply compliance with local building code requirements. It is the
responsibility of the contractor/engineer to ensure installation is in
accordance with all local building codes. Confer with local building
officials before installation.
IMPORTANT: Connect the building
return line to the hot water supply line
as close as possible to the water
heater.
NOTE:
For residential and commercial
applications, this piping arrange-
ment maintains full warranty.
Equipment List
Water Heaters
Kit (Optional)
(3/4" Fittings Include:
2 Unions, 2 Ball Valves,
2DrainValvesand
1 Pressure Relief Valve.)
QTY
1
1
Plumbing Installation