Self Cleaning Commercial Gas Water Heaters
with Flue Damper and Electronic Ignition
M O D E L S C O V E R E D
SBD71 120 Through SBD85 500
Also includes Parts List
Part Number STC-072
Printed in the U.S.A. - 0106
COMMERCIAL
The Expert’s Choice®
SBD TANK TYPE HEATERS
SERVICE HANDBOOK
SBD
HANDBOOK
TABLE OF CONTENTS
PAGE PAGE
Troubleshooting (continued)
Introduction 1-2 Troubleshooting the Efflkal 28-30
Wire Harness Test 31
Installation 3 IID Module 32
Clearances 4 Pilot Spark 33
Air Requirements 5-8 Pilot Valve 34-35
Contaminated Air 9 Main Burner Test 36
Flammable 9 Flame Rectification 37
Gas Pressure 10 IID Module 38
Gas Valve 11 Main Gas Valve 39-40
Venting 12-15
Sequence of Operation
Mechanical 16 Service Charts and General
Electrical 17-18 Questions and Answers 41-42
Troubleshooting Parts List 43-50
Transformer 19
High Limit 20-21 Component Part Information 51
Damper (on Standby) 22
PC Board 22-23 Service Check List 52-53
Thermostat 24
Effikal Damper 25 Comments 54
Effikal Harness Test 26 Normal Operation 26-27
SBD SERVICE HANDBOOK INTRODUCTION
This service handbook is designed to aid in servicing and troubleshooting State SBD water heaters in the
field. No duplication or reproduction of this book may be made without the express written authorization of
the State Water Heater Company.
The following text and illustrations will provide you with a step by step procedure to verify proper installation,
operation, and troubleshooting procedures. Additional quick reference data is included to assist you in
servicing this product.
The information contained in this handbook is designed to answer common questions encountered in the
operation of the SBD product line and is not meant to be all inclusive. If you are experiencing a problem not
covered in this handbook, please contact the Technical Information Department at 1-800-365-0577 or your
Local State Water Heater Sales Representative for further assistance. This handbook is intended for use by
licensed plumbing professionals and reference should be made to the installation manual accompanying the
product. This handbook contains supplemental information to the SBD installation and operation manual.
This portion of the handbook will review some often overlooked installation considerations,
taking note of necessary installation requirements for the SBD 71120 through SBD 85500
model heaters. The installation manual covers most of these items in detail.
A 24 inch clearance for all serviceable parts is recommended. Clearances may vary
between SBD models – See instruction manual or the label on the heater, for clearances
applicable to your specific model.
"Copyright by the American Gas Association. Used by permission of the copyright holder".
This illustrates the exterior roof clearances for SBD units with natural draft venting. The
vent shall extend at least 3 feet above the highest point where it passes through a roof of
a building, and at least 2 feet higher than any portion of a building within a horizontal
distance of 10 feet (for vents of 12" in diameter or less). (NFPA 54 ANSI Z 223.1 SEC
7.5.2a). (Sec 7.6.2a may allow reduction to 8 feet with a “ Listed vent cap”).
Stoichiometric or theoretical complete combustion requires 10 cubic feet of air per 1000
BTUH input of the gas input. The National Fuel Gas Code also recommends an
additional 2.5 cu.ft. of "excess" air. This 12.5 cu.ft minimum supply air per 1000 BTUH
input applies to natural and propane gas models.
The National Fuel Gas Code also specifies minimum make-up air opening sizes for
various building installations. (Ref: NFPA 54, ANSI Z223.1, sec 5.3)
A fresh supply of make-up air for combustion can be supplied to the heater through makeup air ducts which directly communicate with the out of doors. Two openings are required
- one within 12 inches of the top of the enclosure and one within twelve inches of the
bottom of the enclosure. Each opening shall have a free area of not less than 1 square
inch per 4000 BTUH of the total input of all appliances within the enclosure.
The lower opening is primarily providing combustion air. The upper opening is providing
vent dilution air and acts as a relief opening for flue gases should the vent become
obstructed or a downdraft condition occur. Additionally, when the heater is installed in a
confined space and communicating with the outdoor air, one permanent opening,
commencing within 12 in. (30 cm) of the top of the enclosure, shall be permitted where
the equipment has clearances of at least 1 in. (2.5 cm) from the sides and back and 6 in.
(16 cm) from the front of the appliance. The opening shall directly communicate with the
outdoors and shall communicate through a vertical or horizontal duct to the outdoors or
spaces (crawl or attic) that freely communicate with the outdoors, and shall have a
minimum free area of:
a. 1 sq. in. per 3000 BTU per hr (7 cm
located in the enclosure, and
b. Not less than the sum of the areas of all vent connectors in the confined space.
Often it is more practical to install vertical make-up air ducts to the out doors. Again, two
openings are required - one within 12 inches of the top of the enclosure and one within
twelve inches of the bottom of the enclosure. Each opening shall have a free area of not
less than 1 square inch per 4000 BTUH of the total input of all appliances within the
enclosure.
MAKE-UP AIR
HORIZONTAL DUCTS
When the heater is installed in an interior room with no roof access for vertical ducts,
horizontal make-up air ducts should be installed. When using horizontal ducts, two
openings are required - one within 12 inches of the top of the enclosure and one within
twelve inches of the bottom of the enclosure. Each opening shall have a free area of not
less than 1 square inch per 2000 BTUH of the total input of all appliances within the
enclosure.
Insufficient make-up air is a major cause of combustion problems. One common example
is in a restaurant installation where exhaust vent equipment was not considered in sizing
make-up air requirements. This may result in air being backdrafted by the restaurant
exhaust equipment through the heater causing flue gas spillage, flame roll out, improper
combustion, inconsistent pilot operation, and/or erratic heater shut down.
Along with adequate make-up air, the quality of the air is important. Contaminants in
combustion air can lead to premature heater failure. Vapors from bleaches, soaps,
waxes, salts, etc. are drawn into the combustion chamber with the make-up air and, once
fired, mix with water vapor in the gases to form extremely corrosive hydrochloric or
hydrofluoric acid and other corrosive byproducts.
AIR FOR COMBUSTION
Flammable Items
Flammable items, pressurized containers or any other potentially hazardous articles must
never be placed on or adjacent to the heater. Open containers of flammable material
should not be stored or used in the same room with the heater.
The supply gas pressure is normally measured at the dirt leg or at the gas pressure
tapping on the gas supply shutoff valve. This reading must be measured with 'flowing'
gas.
The manifold gas pressure is measured at the manifold pressure tap of the gas valve
when the gas is flowing.
The gas valves used on all SBD water heaters are
24 volt AC combination step opening gas valves.
They incorporate the pilot valve, main valve, and gas
pressure regulators into one body. The inlet view of
the valve features a filter screen and the top knob.
The top knob is a manual on/off gas control for both
the pilot and main gas valves. When the top knob is
placed on the black mark, gas is supplied only to the
pilot valve.
On the top view, we see the pilot solenoid and
pilot and main gas regulators. The top view also
displays the “TH and “TR” terminals. The pilot
gas regulator is found under its cover screw. It is
factory preset at 3.5” W.C. but can be adjusted from
2.5 to 5 inches water column. The main gas
regulator is found under its cover screw. It is
factory preset to 3.5 inches W.C. and adjusts gas
pressure output from 2.5 to 5 inches water
column. The two electrical terminals are marked
TH and TR. The TH terminal is the common
between the pilot valve solenoid coil and the main
valve solenoid coil. The other wire emerging from
the pilot solenoid connects to the pilot valve
electrical output on the IID (terminal PV). The TR
terminal connects directly to the main valve
electrical output from the IID module
(terminal MV).
On the outlet view of the gas valve, we see the
pilot gas connection port, manifold gas connection
port, a limited bleed vent port, the manifold gas and
pressure tap.
All SBD water heaters are classified by ANSI as category I (non-condensing, negative
pressure venting) appliances. They are approved for type B vent.
For larger applications, SBD water heaters can be common vented together either in a
tapered manifold or constant size manifold. (Follow National Fuel Gas Code
requirements for sizing and installation.)
Combined Vents
When vents are combined, the area of the combined vent should be equal to area of the
largest single vent, plus 50% of area of all others joining.
EXAMPLE: To combine two 6” vents with an
8” vent, the area of a combined vent should be
one half area of two 6 inch vents (14 + 14)
plus area of 8 inch vent (50) or 78 sq. inches.
Referring to chart, 78 sq. inches require 10”
diameter vent.
SBD water heaters can be used with power vent
kits for sidewall venting. State offers power vent
kits for use on installations with a maximum of
100 equivalent feet of vent piping. The power
vent kits also use type B vent materials. When
power venting, specific exterior clearances must
be maintained, as outlined in the National Fuel
Gas Code. (NFPA 54, ANSI A223.1, sec 7.8)
To understand SBD tank type water heaters, an examination of their sequence of
operation is necessary.
When the thermostat calls for heat, the relay in the draft hood assembly activates the
flue damper motor. The damper opens and power flows to the IID (Intermittent
Ignition Device). This activates the IID module to open the pilot valve and begin
sparking at the pilot burner assembly. Once the pilot flame is established and
confirmed back to the IID, the sparking is stopped and the main gas valve is opened,
allowing gas flow to the main burner. When the thermostat satisfies, main and pilot
gas is shut off. Damper is returned to closed position.
STEP 2. HIGH LIMIT, LEFT TERMINAL TEST. Test for 24 VAC between the left high
limit terminal and ground.
IF THEN
The meter does not read 24 VAC: • Check wiring between transformer and
high limit.
The meter reads 24 VAC: • Go to Step 3.
Note: The high limit (Energy Cut Off) opens if the tank water temperature exceeds 205
degrees. The control is resettable (manually) when the tank water temperature drops
below 185 degrees.
STEP 3. TO TEST HIGH LIMIT RIGHT TERMINAL. Ensure that the jumper wire
between the high limit and thermostat is connected, and the damper motor power line is
connected. Test for 24 VAC between the high limit right terminal and ground.
IF THEN
The meter does not read 24 VAC: • Push the reset button and redo the test (storage
water temperature below 185 degrees).
The meter reads 24 VAC: • Go to step 4.
After Push in Reset - 24 VAC is now present
Reasons For Resetting
Condition Cause Solution
High limit open Never set on initial
installation
Excessive water temperature Faulty thermostat Replace dual control
Heater shut down before
reaching thermostat setting
Note: The right terminal of the high limit has a jumper wire connected to the left terminal of the
thermostat. There is also a black wire connecting to the damper motor assembly. This black
supplies power to the motor to close the damper during periods of standby.
STEP 4. INSPECT THE DAMPER. Lower the thermostat setting so the unit will not be
calling for heat, then inspect the damper.
IF THEN
If the damper is open: • Go to step 5.
If the damper is closed: • Go to step 7.
Note: If the water temperature in the tank is below 120 degrees F, temporarily disconnect the
jumper wire between the high limit and thermostat to simulate a satisfied thermostat.
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STEP 5 CHECK THE PC BOARD
STEP 5. CHECK THE PC BOARD. Test for 24 VAC between the black PC board wire
connection and ground.
IF THEN
24 VAC is not present: • Check the black wire connections
The wiring colors from the damper PC Board are different colors than the wires on the
heater wiring harness. The male/female plugs to connect the damper board to the heater
harness join in only one way.
Adapter
Plug
Service
Switch
Service
Switch
Heater
Harness
Effikal Control Cover (Photo of kit mounting) Effikal Style
Motor
Lead
Terminal
Adapter not necessary on production 110,111 Series
The heater harness wires still serve the same function:
Black – 24V Constant if high limit closed
Yellow – 24V To damper if the thermostat is closed
Red – 24V From damper to IID if damper closes end switch
White – Neutral (common)
STEP 14A. PILOT VALVE - OHM TEST. If pilot assembly is sparking but no pilot flame
is established, disconnect the pilot valve solenoid leads. Using a multimeter, (set to read
ohms) test for 20* ohms resistance +/- 5 through the solenoid coil.
IF THEN
The meter dose not read 20 ohms plus or
minus 5:
The meter does read 20 ohms plus or
minus 5:
• Replace gas valve
• Gas valve should work. Also check that
pilot gas is present and pilot tube or
orifice are not blocked
The MV/PV wire on the IID is connected to the white wire
The MV wire on the IID is connected to the red wire.
STEP 14B. PILOT VALVE TEST – SBD 500 ONLY. Testing the two coils of the
Honeywell VR8404P 5004 gas valve used on the model SBD 500 only. Because of built
in diodes, it is difficult to test for ohms resistance through these coils. The following is a
DC amperage check of the main and pilot coils.
Condition:
• Tank calls for heat
• PV terminal of module has 24 Vac
• No Pilot flame
Test Procedure:
• Turn off power to heater
• Meter set to test for DC amperage (on meters, the black wire is in the “com”
port, the red wire is in the “10A” port, the dial is set to 20M/10A in the DC AMP
test area).
• Blue “PV” wire is disconnected from the ignition PV terminal.
• Install meter in series between gas valve and ignition module – 10A wire to blue
gas valve lead, common wire to PV module terminal.
• Turn power on to heater, after module receives 24V
Test DC Amperage through Pilot coil of gas valve
IF THEN
.75 to .85 DCA is not present: • Replace the gas valve
.75 to .85 DCA is present • Pilot should work if gas (not air) is present to pilot
Power off, reattach blue gas valve wire to PV terminal of module.
Note: Flame rectification means that an alternating current (AC) signal is changed to a direct current (DC)
signal. The pilot flame is the 'switch' which connects the pilot hood to the igniter and ground. If the pilot
hood and igniter sensor had the same surface area, the flame 'switch' would conduct an AC signal.
Because the pilot surface is greater than the igniter surface, the signal becomes a DC current that the
module can interpret. The pilot hood must be properly grounded and the pilot flame must remain in contact
with both surfaces for the flame proving signal to remain constant.
If the signal is broken for just 8 tenths of a second, the heater will cycle off.
Sparking at the pilot will continue if an insufficient signal is received by the module.
Sparking at the pilot will stop almost immediately after the ignition module senses the pilot flame.
STEP 18A. MAIN GAS VALVE CHECK. Disconnect wires from gas valve TH and TR
terminals. Using a multimeter, test for 68 ohms plus or minus 5 between TH and TR on
the main valve coil.
IF THEN
The meter reads ‘O’ or infinity • Replace the gas valve
The meter reads 68* ohms plus or minus 5 • The main burner will ignite
Q. What is unique about the Canadian – SBC-CGA – models vs. U.S. SBD models?
A. The Canadian models have different dimensions to meet Canadian code requirements.
Q: How much electrical power is required for a SBD water heater?
A: The SBD models draw approximately .7 Amps at 120VAC.
Q: The units require "leg kits" to meet National Sanitation Foundation standards.
Q: When should SBDs be delimed? NOTE: The “Hydrocannon” should eliminate or greatly
reduce the lime build up rate from the water heater.
Many variables affect the liming up process including:
water temperature - The amount of lime precipitation during the same period of time will be
nearly 2 times greater if water is stored at 140 degrees F than at 120 degrees F. A 180
degree setting will precipitate lime about seven times as fast as a 140 degree F setting.
volume of water - The more gallons flowing through the SBD, the more exposure to
accumulation.
hardness – The harder the water the higher the possibility of lime build up. 1 to 3.5 grains
per gallon is "soft", 3.5 to 7 grains per gallon is "moderate", 7 to 10.5 grains per gallon is
"hard" and 10.5 + grains per gallon is "very hard". (An aspirin is about 5 grains. One grain is
equal to 17.1 parts per million.)
A: Deliming should be done when a slight rumbling or popping sound is detected when the
main burners are on.
Q: What effect will lime build-up have on the SBD water heater?A: One eighth inch of scale build-up may reduce efficiency as much as 22%; a 1/4 inch build-
up, as much as 38%.
A: Less efficient heat transfer means more bottom head expansion/contraction stress and
premature leakage.
A: Heavy build-up on the bottom head and bottom portion of the flue pipes leads to more heat
transfer at the top of the flues. This can lead to stacking or erratic thermostat operation.
A: The “Hydrocannon” greatly reduces the possibility of lime build-up.
Q: Anode rods provide additional protection against corrosion. When should these be
replaced?
A: When large gouges or pits appear in the anodes, replace them. It is recommended that
(This service checklist may be photo copied to assist with SBD service call.)
This checklist is intended to aid the Service Agent in determining that the State SBD
Water Heater has been properly installed and is operating correctly. Because the
circumstances of each installation may vary greatly, it is not intended to be an allinclusive list of the problems that the Service Agent may encounter. Any item checked
"no" on this list should be thoroughly investigated and corrective action taken, if
required.
SERVICE AGENT INSTALLATION DATE
MODEL NUMBER SERVICE DATE
SERIAL NUMBER LOCATION ADDRESS
GAS TYPE - CHECK ONE
NATURAL PHONE( ) ___ - ____
PROPANE
I. Check Clearances (circle answer)
A. Are exterior clearances adequate? yes no
B. Are interior clearances adequate? yes no
Comments:
II. Check Makeup Air Requirements
A. Is the quantity of make-up air adequate per the National Fuel Gas Code? yes no
Comments: B. Is the quality of make-up air adequate? yes no
Comments:
III. Gas Pressure (fill in blank)
A. Supply gas pressure
B. Manifold gas pressure (main burner)
Comments:
IV. Venting (check)
A. Properly sized per the National Fuel Gas Code? yes no
B. Does the installation have mechanically assisted venting? yes no
V. WATER PIPING
Is the system properly sized? yes no
Is the system properly installed? yes no
Are there any water leaks? yes no
Does the installation have a recirculating system? yes no
If so, is it operational? yes no
VI. PROPER SEQUENCE OF OPERATION
During standby does damper close on standby? yes no
During standby is pilot flame off? yes no
On a call for heat does thermostat close? yes no
On a call for heat does damper open completely? yes no
Does sparking begin at pilot? yes no
Is pilot flame established? yes no
If so, does sparking stop? yes no
Does main burner ignite? yes no
Does the thermostat satisfy? yes no
Does damper close? yes no
Comments:
VII. SAFETY
A. Gas
Does pilot flame prove before main burner ignites? yes no
Does damper blade fully open before ignition sequence occurs? yes no
Is burner cover plate in place? yes no
Is burner floor shield in place? yes no
Does IID lockout occur after 30 sec. trial for ignition? (Propane models only) yes no
B. Water Temperature
Is the thermostat adjusted to the lowest acceptable temperature? yes no
Does the installation have a mixing valve? yes no
If so, is it operational? yes no
What is the outlet temperature of the mixing valve?
Is a properly rated temperature and pressure relief valve installed? yes no
C. Electrical
Is the 120 VAC electrical power supply properly wired? yes no
Are all the SBD control covers in place? yes no
Is the 120 VAC electrical power supply properly fused? yes no
D. Flammables
Are flammable materials located in the area of the water heater? yes no
Are flammable vapors located in the area of the water heater? yes no
(This service checklist may be photo copied to assist with SBD service call.)