State Industries ROOFTOP SRT80 120NE User Manual

Rooftop Water Heater Model SRT80 1 20NE

COMMERCIAL GAS W A TER HEA TER

GAS-FIRED POWER BURNER

FOR DOMESTIC HOT W A TER

• INST ALLA TION • OPERA TION • SERVICE • MAINTENANCE • LIMITED W ARRANTY

Thank you for buying this energy efficient water heater from
State Industries. We appreciate your confidence in our
products.

W ARNING: 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.

CAUTION

TEXT PRINTED OR OUTLINED IN RED CONTAINS
INFORMATION RELATIVE TO YOUR SAFETY. PLEASE
READ THOROUGHL Y BEFORE INST ALLING AND USING
THIS APPLIANCE.

– Installation and service must be

performed by a qualified installer,
service agency or the gas supplier .

PLACE THESE INSTRUCTIONS ADJACENT TO HEA TER AND

NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.

PRINTED IN U.S.A. 1005 PART NO. 1 97242-000

1

500 Tennessee Waltz Parkway

Ashland City, TN 37015

www.statewaterheaters.com

SUPERSEDES PART NO. 196758-000

TOP VIEW

ROOFTOP SRT80-120NE
ROUGH-IN-DIMENSIONS

RIGHT SIDE VIEW

LEFT SIDE VIEW

GAS VAL VE PIPING

SRT80-120 1/2" NPT

FRONT VIEW

T able 1. RECOVERY CAP ACITIES - NA TURAL GAS / L.P.

BTU Gallon

Model Input Capacity 30 40 50 60 70 80 90 100 110 120 130 140

SRT80-120

Recovery capacities are based on heater performance at 80% thermal efficiency .

120,000 80 388 291 233 194 166 145 129 116 106 97 90 83

35.17 kwh 303L (1469) (1102) (882) (734) (628) (549) (488) (439) (401) (367) (341) (314)

Approx.

TEMPERATURE RISE - DEGREES °F - GALLONS PER HOUR (LPH)

2

INST ALLA TION INFORMA TION

OUTBACK

Installation Information

Model: SRT 80-1 20NE series Input: 120,000 btuh
Electrical: 120/24V AC/60 Hz/5 A Side Clearances: 0"
Maximum Inlet Pressure: 14"WC T op Clearances: 1.50"
Manifold Pressure: 4.50"WC Unit is Polarity Sensitive
Minimum Inlet Pressure: 6.2"WC No external venting required

Warnings

Dummy hot return required if hot return from appliance is not used*
Avoid flex gas line usage
Avoid use of forklift truck to mount unit on outdoor stand
Provide enough clearance to service unit

Available Kits

Anti-freeze kit
Remote Interface kit

3

FOREWORD

This design complies with the current edition of ANSI Z21.10.3 as
an automatic circulating tank type water heater and automatic
storage water heater.

Detailed installation diagrams are found in this manual. These
diagrams will serve to provide the installer with a reference for the
materials and methods of piping necessary. It is highly essential
that all water, gas piping and wiring be installed as shown on the
diagrams.

Particular attention should be given to the installation of
thermometers at the locations indicated on the diagrams as these
are necessary for checking the proper functioning of the heater.

TABLE OF CONTENTS

PAGE PAGE

ROUGH-IN DIMENSIONS .................................................................... 2

INST ALLATION INFORMA TION........................................................... 3

FOREWORD ....................................................................................... 4

FEATURES ......................................................................................... 5

Water Temperature Control........................................................... 5

High Limit Switch (E.C.O.) ............................................................. 6

Dishwashing Machine Requirement ............................................. 5

Circulating Pump............................................................................ 6

PLUMBING MANIFOLD ASSEMBL Y ................................................... 6

Flow Diagram ................................................................................ 5

Automatic Air Bleed Valve ............................................................ 5

Hot Return Recirculation Pump ..................................................... 7

Drain Valve.................................................................................... 7

AIR SYSTEM ASSEMBL Y .................................................................. 7

Blower Assembly.......................................................................... 7

Blower Plenum .............................................................................. 7

Air Hose ........................................................................................ 8

Flue Adapter.................................................................................. 8

Exhaust Vent ................................................................................. 8

CONTROL SYSTEM ........................................................................... 8

Blocked Outlet Switch .................................................................. 8

Blocked Inlet/Prover Switch .......................................................... 8

Low Gas Pressure Switch ........................................................... 9

On/Off Switch ............................................................................... 9

Hot Surface Igniter ........................................................................ 9

OIM - Outdoor Interface Module ................................................... 9

WR Ignition Control Board ............................................................. 9

Low Water Cutoff Board and Probe ............................................ 10

Thermostat/E.C.O. Probes ............................................................ 10

Transformer .................................................................................. 10

Junction Box ................................................................................. 10

TANK ASSEMBLY SYSTEM .............................................................. 10

T ank Insulation............................................................................... 10

CABINET ASSEMBLY......................................................................... 11

Cabinet Panels .............................................................................. 11

ADDITIONAL CONTROLS .................................................................. 11

Gas Valve ...................................................................................... 11

Flame Sensor ................................................................................ 11

INSTALLA TION INSTRUCTIONS ......................................................... 11

Required Ability ............................................................................. 11

Insulation Blankets ........................................................................ 11

Locating The Heater...................................................................... 11-12

Provide Unit Support ..................................................................... 12

Roof Curb ...................................................................................... 12-13

Rig and Place Unit ......................................................................... 13

Outdoor Stand ............................................................................... 14

Clearances .................................................................................... 14

Hard Water .................................................................................... 14

Air Requirements .......................................................................... 14

In addition to these instructions, the equipment shall be
installed in accordance with all local codes. The authority
having jurisdiction should be consulted before installing.

In the absence of local codes, the installation must comply
with the current editions of the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 and the National Electric Code, NFPA 70.
The former is available from the Canadian Standards
Association, 8501 East Pleasant Valley Road, Cleveland, OH
44131, and both documents are available from the National
Fire Protection Association, 1 Batterymarch Park, Quincy, MA

02269.

Chemical Vapor Corrosion ............................................................ 14

VENTING ............................................................................................ 15

Vent Terminals ............................................................................... 15

Pressure Switches ....................................................................... 15

Gas Piping ..................................................................................... 15-16

Connection of Gas Pipe ................................................................ 16

Purging .......................................................................................... 16

Gas Meter Size - City Gases Only ............................................... 16

Gas Pressure Regulation.............................................................. 16

Gas Valves .................................................................................... 17

SYSTEM CONNECTIONS ................................................................... 17

Thermometers ............................................................................... 17

Relief Valve ................................................................................... 17

Water Line Connections ............................................................... 17

Closed System .............................................................................. 17

Water (Potable) Heating and Space Heating ................................ 17

Water Heater Wiring...................................................................... 17-18

OPERATION........................................................................................ 19-20

Sequence of Operation ................................................................ 21

Error Codes ................................................................................... 21

Fault Conditions............................................................................. 21-22

PRIOR TO ST ART-UP ......................................................................... 22

Required Ability ............................................................................. 22

OPERATING INSTRUCTIONS.............................................................. 23

Adjustment Procedure (Initial Start-Up) ........................................ 23-24

Cathodic Protection....................................................................... 24

Precautions ................................................................................... 24

Lighting & Operating Label............................................................ 25

GENERAL INFORMA TION .................................................................. 26

Power Burner ............................................................................... 26

High Limit ....................................................................................... 26

High Altitude Installations .............................................................. 26

MAINTENANCE .................................................................................. 26

General.......................................................................................... 26

Maintenance Schedule ................................................................. 26

Flushing ......................................................................................... 26

Draining ......................................................................................... 26

Sediment Removal......................................................................... 26

Lime Scale Removal ...................................................................... 26-27

Anode Inspection and Replacement............................................. 27

Drain Valve and Access Panels ................................................... 27

Relief Valve ................................................................................... 27

Circulating Pump............................................................................ 27

Vent System .................................................................................. 27

INSTALLA TION DIAGRAMS ............................................................... 28-32

CHECKLIST AND SERVICE INFORMATION ........................................ 33

TROUBLE-SHOOTING........................................................................ 33-34

REPLACEMENT PARTS ...................................................................... 34

LIMITED WARRANTY......................................................................... 35

4

FEATURES

IMPORT ANT

IT IS REQUIRED THAT A QUALIFIED SERVICE TECHNICIAN
PERFORM THE INITIAL FIRING OF THE HEATER.

A CHECKLIST AND SER VICE INFORMATION section are included
at the rear of this manual. By using this checklist the user may be
able to make minor operational adjustments and save himself
unnecessary service calls. However, the user should not attempt
repairs which are not listed in this section.

WA TER TEMPERA TURE CONTROL

DANGER

THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT
WATER TEMPERATURES REQUIRED FOR AUTOMATIC
DISHWASHER AND LAUNDRY USE CAN CAUSE SCALD BURNS
RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEATH.
THE TEMPERATURE A T WHICH INJURY OCCURS V ARIES WITH
THE PERSON’S AGE AND TIME OF EXPOSURE. THE SLOWER
RESPONSE TIME OF CHILDREN, THE ELDERLY OR DISABLED
PERSONS INCREASES THE HAZARDS TO THEM. NEVER ALLOW
SMALL CHILDREN TO USE A HOT WATER TAP, OR TO DRAW
THEIR OWN BATH W A TER. NEVER LEAV E A CHILD OR DISABLED
PERSON UNATTENDED IN A BA THTUB OR SHOWER.

Figure 1 shows the approximate time-to-burn relationship for
normal adult skin. Short repeated heating cycles caused by small
hot water uses can cause temperatures at the point of use to
exceed the thermostat setting by up to 20°F/-1 1°C. If you experience
this type of use, you should consider using lower temperature
settings to reduce scald hazards.

Temperature Time to Produce 2nd & 3rd

Setting Degree Burns on Adult Skin

180°F / 82°C Nearly instantaneous
170°F / 77°C Nearly instantaneous
160°F / 71°C About 1/2 second
150°F / 66°C About 1-1/2 seconds
140°F / 60°C Less than 5 seconds
130°F / 54°C About 30 seconds
120°F / 49°C More than 5 minutes

FIGURE 1

Valves for reducing point-of-use temperature by mixing cold and
hot water are available (see Figure 2). Also available are
inexpensive devices that attach to faucets to limit hot water
temperatures. Contact a licensed plumber or the local plumbing
authority.

THE WA TER HEA TER SHOULD BE LOCA TED IN AN AREA WHERE
THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO SET
TEMPERATURES.

The water temperature is controlled using the Touch Pad Buttons
on the Display at the front of the unit (See Figure 1). This control
utilizes two temperature probes to determine the tank temperature.
The upper temperature probe is located on top of the unit in the
back and the lower probe is located on the front center axis of the
tank.

The temperature may be adjusted from 70°F/21°C to 180°F/82°C.
The thermostat was adjusted to 70°F/21°C before the heater was
shipped from the factory. It is recommended that lower water
temperatures be used to avoid the risk of scalding. It is further
recommended, in all cases, that the water temperature be set for
the lowest temperature which satisfies your hot water needs. This
will also provide the most energy efficient operation of the water
heater and minimize scale formation.

SETTING THE WATER HEATER TEMPERATURE AT 120°F/49°C
WILL REDUCE THE RISK OF SCALDS. Some states require
settings at specific lower temperatures.

FIGURE 2

5

HIGH LIMIT SWITCH (E.C.O.)

The top immersion well of the upper probe also contains the high
limit (energy cutoff) sensor. The high limit switch interrupts the
main burner gas flow should the water temperature reach
approximately 199°F/93°C.

Should the high limit switch activate, it must be reset by cycling
power to the unit. The water temperature must drop below 180°F/
82°C before the controller can be reset.

Continued manual resetting of the high limit control, preceded
by higher than usual water temperature is evidence of high
limit switch operation. For example, a malfunction of the control
system allowing the gas valve to stay open could cause water
temperature to rise until the high limit switch opens. Contact
your dealer or servicer if continued high limit switch operation
occurs.

DISHWASHING MACHINE REQUIREMENT

All dishwashing machines meeting the National Sanitation
Foundation requirements are designed to operate with water
flow pressures between 15 and 25 pounds per square inch
(103 kPa and 173 kPa). Flow pressures above 25 pounds per
square inch (173 kPa), or below 15 pounds per square inch
(103 kPa), will result in improperly sanitized dishes. Where
pressures are high, a water pressure reducing or flow
regulating control valve should be used in the 180°F (82°C)
line to the dishwashing machine, and should be adjusted to
deliver water between these limits.

The National Sanitation Foundation also recommends circulation
of 180°F (82°C) water. Where this is done, the circulation should
be very gentle so that it does not cause any unnecessary
turbulence inside the water heater. The circulation should be
just enough to provide 180°F (82°C) water at the point of take­off to the dishwashing machine. Adjust flow by means of the
plug cock in the circulating line. (See INSTALLATION DIAGRAMS
section.)

CIRCULATING PUMP

A circulating pump is used when a system requires a circulating
loop or there is a storage tank used in conjunction with the heater.
Refer to the piping diagrams at rear of manual for electrical hookup
information and install in accordance with the current version of
the National Electric Code NFPA No. 70.

All bronze circulators are recommended for use with commercial
water heaters.

Although circulators are oiled and operated by the manufacturer
some circulators must be oiled again before being operated.
Please refer to manufacturer's instructions.

PLUMBING MANIFOLD ASSEMBLY

FLOW DIAGRAM

FIGURE 3

AUTOMA TIC AIR BLEED V AL VE

The tank assembly utilizes an automatic air bleed valve. The
purpose for this automatic air bleed valve is to allow air to escape
the tank when the unit is filled with water. When the unit is drained,
the opposite occurs with the valve allowing air to replace the drained
water. It removes the pressure vacuum that occurs in the system
causing incomplete drainage. This valve is automatic which allows
it to sense when the tank assembly is filled with water, see
Figure 4.

The plumbing manifold assembly is composed of several
components with each having a unique function. Please see
Figures 3, 5, and 6 to observe the water flow to the plumbing
manifold assembly and the components that make it up.

FIGURE 4

6

HOT RETURN RECIRCULA TION PUMP

BLOWER ASSEMBLY

The hot return recirculation pump circulates the hot water through
the hot water line to eliminate delays at plumbing fixtures, see
Figure 5.

FIGURE 5

DRAIN V ALVE

The drain valve is used to drain the water from the tank assembly
and plumbing manifold assembly, see Figure 6.

The blower assembly functions by pulling in air from outside the
unit to supply to the burner assembly for proper combustion. The
blower pushes the air through the burner assembly and heat
exchanger where the flue gases then exit the exhaust system
assembly, see Figure 8.

FIGURE 8

BLOWER PLENUM

FIGURE 6

AIR SYSTEM ASSEMBLY

The air system assembly is comprised of the blower assembly,
blower plenum, air hose, and inlet vent terminal. This is where
combustion air is acquired for combustion, see Figure 7.

The blower plenum is used to draw air into the blower inlet. The
inlet of the air system must maintain enough height from the ground
to take into account yearly snow levels to prevent possible inlet
vent blockage. The air plenum allows the blower to pull air into the
unit from a higher inlet location to provide protection required, see
Figure 9.

FIGURE 7

FIGURE 9

7

AIR HOSE

CONTROL SYSTEM

The air hose is used to provide a flexible air path from the blower
to the burner assembly. It is held in place with two standard hose
clamps, see Figure 10.

FIGURE 10

FLUE ADAPTER

The flue adapter is made of a flat metal plate with an exhaust
adapter to mate with the exhaust elbow. This is where the flue
gases exit the heat exchanger. This is a very hot region and is
covered with a layer of high temperature fiberglass insulation, see
Figure 11.

The control system is comprised of an Outdoor Interface Module
that monitors the functions of the WR ignition system, pressure
switches, low water cutoff and temperatures in the tank.

FIGURE 13

BLOCKED OUTLET SWITCH

The Blocked Outlet Switch is set up to shut the unit off when a
pressure buildup in the exhaust vent pipe occurs. This switch is a
positive pressure switch that requires an increase in pressure to
change the electrical contacts from normally closed to open. When
this switch prevents the unit from igniting, most likely the exhaust
is blocked. Check for obstructions in the exhaust venting and
exhaust vent terminal, see Figure 14.

FIGURE 11

EXHAUST VENT

The exhaust vent elbow mates with the flue adapter. The elbow
mates with the exhaust terminal to dispose the flue gases to the
outdoors. This venting section is covered with a fiberglass
insulated wrap to protect from heat and condensation. These
pipes are sealed with a high temperature gasket integral to the
vent pipe fittings, see Figure 12.

FIGURE 12

BLOCKED INLET/PROVER SWITCH

The Blocked Inlet/Prover Switch is set up to shut the unit off when
a reduction in pressure in the intake vent occurs. This switch is a
negative pressure switch that requires an increase in negative
pressure to change the electrical contacts from normally open to
closed. The switch is connected to the pressure tap connected to
the housing of the blower. When this switch prevents the unit from
ignition, most likely the intake is blocked. Check for obstructions in
the inlet vent terminal, see Figure 14.

FIGURE 14

The blocked Inlet/Prover Switch has a second function. It is provided
on the heater to verify that the fan is operating. When the fan
increases in negative pressure, the electrical contacts close
signaling that the blower is operational and is at peak performance.
The controller requires that the electrical contacts on the switch
close before it will allow the blower to come on.

8

LOW GAS PRESSURE SWITCH

OIM - OUTDOOR INTERFACE MODULE

The Low Gas Pressure Switch is a single pole, normally open
pressure switch that will close its contacts when a rising pressure
of 6.2 inches (1.53 kPa) w.c. is encountered. The contacts will
open when the pressure falls below the fixed set point of 6.2 inches
of w.c. The Low Gas Pressure Switch monitors the gas supply
pressure to the heater. If the gas supply falls below the 6.2 inches
of w.c., the main burner is extinguished (if heater is running) or the
heater will not start up, see Figure 15.

FIGURE 15

ON/OFF SWITCH

The ON/OFF Switch is a single pole, single throw rocker switch.
This switch provides 120V from the electrical source to the heater,
see Figure 16.

The OIM is a device that monitors the control system. It monitors
the ignition control assembly, the tank and outlet temperatures,
the low water cutoff device, and the pressure switches. The display
board provides operating information. It records and logs error
messages for diagnostics. The module is equipped with a touch
pad for easy access to observe menus and current status of
control, see Figure 18.

FIGURE 18

WR IGNITION CONTROL BOARD

The WR Ignition Control Board performs the ignition sequence for
the water heater. It controls the diagnostics of the system and
monitors all the pressure switches, the flame sensing device, the
thermostats, the E.C.O., and components that make up the control
system. The difference between the WR Ignition Control Board is
that the OIM board monitors all the controls and provides that
information through the LCD display where the WR Ignition Control
Board provides the means to control the complete sequence of
operation and switches, see Figure 19.

FIGURE 16

HOT SURFACE IGNITER

The Hot Surface Igniter is a device that ignites the main burner by
high temperature (1800°F). When the 120 VAC is applied to the
igniter, sufficient heat is generated to ignite the main burner.
Although improvements have been made to strengthen the igniter,
it is still fragile and care must be taken when handling the igniter to
prevent breakage, see Figure 17.

FIGURE 17

FIGURE 19

9

LOW WA TER CUT OFF BOARD AND PROBE

The Low Water Cutoff Board and Probe monitors the water level to
confirm the tank is completely full. This function is very important
when the unit is first filled with water and when complete loss of
power is encountered during freezing temperatures (in case the
unit drains while using the anti-freeze kit), see Figure 20.

FIGURE 20

THERMOST A T/E.C.O. PROBES

The Outback utilizes a two probe system. The upper probe located
on top of the unit toward the back of the cabinet consists of a
thermostat and E.C.O. The thermostat monitors the top temperature
in the tank. The E.C.O. high limit switch interrupts the main burner
gas flow should the water temperature reach approximately 205°F.
The lower probe measures the water temperature in the lower half
of the tank assembly.

grounding screw to tie into the metal panel to assure the unit is
grounded, see Figure 23.

FIGURE 23

TANK ASSEMBLY SYSTEM

The Tank Assembly is an 80 gallon unit with a U-shaped heat
exchanger. It incorporates two inlet tubes to control flow inside the
tank. The heat exchanger is equipped with a stainless steel baffle
which is non-removable. The working pressure is 150 psi, see
Figure 24.

FIGURE 21

TRANSFORMER

The control system utilizes a 120/24 VAC step down transformer.
Most of the control system utilizes 24 VAC for operation. See wiring
diagram for those components utilizing 24 VAC and 120 VAC, see
Figure 22.

FIGURE 22

FIGURE 24

TANK INSULA TION

The tank assembly is wrapped in foam insulation sealed inside a
round jacket. The ends of the tank consist of high temperature
fiberglass insulation and foam dams to prevent foam leakage,
see Figure 25.

JUNCTION BOX

The junction box is where the 120 VAC is supplied to the unit and
tied into the rest of the controls. The junction box provides a

FIGURE 25

10

CABINET ASSEMBLY

FLAME SENSOR

CABINET P ANELS

There are five panels that comprise the cabinet assembly. The
ends of the cabinet allow access to all controls and plumbing.
Please confirm all joints are attached correctly and sealed to
prevent water leakage inside the cabinet, see Figure 26.

FIGURE 26

The flame sensor is used to sense the burner flame. When there
is sufficient flame, and the burner is properly grounded, the flame
sensor signals back to the ignition board that the burner is operating
properly and to maintain the operation of the gas valve until the
thermostat is satisfied.

FIGURE 28

INSTALLATION INSTRUCTIONS

REQUIRED ABILITY

INSTALLA TION OR SERVICE OF THIS WA TER HEATER REQUIRES
ABILITY EQUIV ALENT TO THAT OF A LICENSED TRADESMAN IN
THE FIELD INVOL VED. PLUMBING , AIR SUPPL Y , VENTING, GAS
SUPPL Y AND ELECTRICAL WORK ARE REQUIRED.

INSULA TION BLANKETS

ADDITIONAL CONTROLS

GAS V AL VE

The gas valve is used to supply the gas to the unit during heat up
periods. The ignition control board monitors the thermostat's call
for heat and sends a signal to the gas valve when to open to allow
gas flow, see Figure 27.

Insulation blankets available to the general public for external use
on gas water heaters are not approved for use on your State
water heater. The purpose of an insulation blanket is to reduce the
standby heat loss encountered with storage tank water heaters.
Yo ur State water heater meets or exceeds the ASHRAE/IES 90.1 b
1999 standards with respect to insulation and standby loss
requirements, making an insulation blanket unnecessary.

LOCA TING THE HEATER

WARNING

THERE IS A RISK IN USING FUEL BURNING APPLIANCES SUCH
AS GAS WATER HEATERS IN ROOMS, GARAGES OR OTHER
AREAS WHERE GASOLINE, OTHER FLAMMABLE LIQUIDS OR
ENGINE DRIVEN EQUIPMENT OR VEHICLES ARE STORED,
OPERATED OR REP AIRED. FLAMMABLE V APORS ARE HEA VY AND
TRAVEL ALONG THE FLOOR AND MAY BE IGNITED BY THE
HEA TER’S IGNITER OR MAIN BURNER FLAMES CAUSING FIRE
OR EXPLOSION. SOME LOCAL CODES PERMIT OPERA TION OF
GAS APPLIANCES IF INSTALLED 18 INCHES (46 cm) OR MORE
ABOVE THE FLOOR. THIS MAY REDUCE THE RISK IF LOCATION
IN SUCH AN AREA CANNOT BE AVOIDED.

THE HEATER SHALL BE LOCATED OR PROTECTED SO IT IS
NOT SUBJECT TO PHYSICAL DAMAGE BY A MOVING VEHICLE.

FIGURE 27

DO NOT LOCATE THE HEATER WHERE NOISE FROM THE
EXHAUST OR INTAKE WILL BE OBJECTIONABLE. THIS
INCLUDES LOCATIONS CLOSE T O OR ACROSS FROM WINDOWS
AND DOORS.

11