A.O. Smith FPS 75 Manual

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Models
FPS40 and 50
Series226-227
FPSE40 and 50
Series 226E
FPD40 and 50
Series226-227
ruc Wc ~~D~w
Preparedby the
Technical
InformationDept.
Irving,Texas FPS75
Series230-233
WATER PRODUCTS
COMPANY
A DIVISION OF A.O. SMITH CORPORATION
00
Printed in the U.S.A. 596 4575 PartNo.TC-O34

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
WORKBOOK INTRODUCTION
Technical Information
Irvino. Texas
1
@1995
A.D. Smith
Water Products Co.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
TABLE OF CONTENTS
SUBJECT PAGE
PAGE
SUBJECT
Service and Operation
Choosing the Best Water Heater
3FPS 40 & 50
Introduction
21
When to choose the FPS 3Sequence of Operation
4Wiring Diagram 22
When to choose the FPSE
When to choose the FPD 5TroubleshootingIndex 23
PartsList 40
Venting Installation
Interior clearances FPS, FPSE, FPD 6FPSE & FPD 40 -50
Exteriorclearances FPS, FPSE 7Sequence of Operation 42
8Wiring Diagram 43
Exterior clearances FPD
9TroubleshootingIndex 44
Condensation
PartsList 66
10
Sealing the vent
Horizontal Length Calc. FPS,FPSE 11 FPS 75
VerticalLength Calc. FPS, FPSE 12 Sequence of Operation 68
13 69
Horizontal Length Calc. FPD
Vertical Length Calc. FPD 14
Wiring Diagram
Troubleshooting 70
PartsList 94
Down Length Calc. FPD 15
Part Infom1ation 96
Air for Combustion
Service Checklist 97
Checking the draft 16
17 General Q & A 99
Additional Problems
19
Negative Pressure
Make-up Air 20

FPS/FPSE/FPDTECHNICALTRAININGAND SERVICEWORKBOOK
CHOOSING THE BEST WATER HEATER
Technical Information
Irving, Texas
3
@1995
A.D.Smith
Water Products Co.

FPS/FPSE/FPDTECHNICAL TRAINING AND SERVICE WORKBOOK
CHOOSING THE BEST WATER HEATER cant.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
CHOOSING THE BEST WATER HEATER cant.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTALLATION

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTALLATION cant.
Exterior installation clearance requirements are crucial and must be met to ensure
compliance with all safety and code requirements. If all clearances cannot be
met, do not unpack the heater.
Exterior
Clearances:
FPS
FPSE All exterior clearance requirements for the FPS and FPSE are measured from the
vent termination.
Min. clearances for side wall venting: Min. clearances for vertical:
Inside corner - 3' l' above or 4' to the side of any
Side of door or window - 4' gable, dormer, or roof structure
Above door or window - l' with building interior access.
Below a window - 4' l' above snow level.
Above public walkway - 7'
Above ground or snow level -1'
Air intake to a living space - 3' above if air intake is within 10'

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTALLATION cant.
Exterior installation clearance requirements are crucial and must be met to ensure
compliance with all safety and code requirements. If all clearances cannot be
met, do not unpack the heater.
Exterior
Clearances:
FPD
All exterior clearance requirements for the FPO are measured from the vent
termination.
Min. clearances for side wall venting: Min. clearances for vertical:
Inside corner - 3' l' above or 4' to the side of any
Side of door or window - 9" gable, dormer, roof structure
Above door of window - 9" with building interior access.
Above public walkway - 7' l' above snow level.
Above ground or snow level -1'
Air intake to a living space - 3' above if air intake is within 10'
@1995
A.D. Smith
Water ProductsCo. Technical Information
IrvinQ.Texas
8

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTAllATION cant.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTAllATION cant.

VENTING INSTAllATION cant.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTAllATION cant.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTAllATION cant.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTALLATION cant.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
VENTING INSTAllATION cant

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
AIR FOR COMBUSTION
Checking for
Draft On initial start up, check for the correct draft on the Power Shot. To check the
draft, place a smoke stick directly in front of the inlet air damper while the heater
is firing. A properly operating system will draw the smoke into the inlet air damper
as shown in the right illustration. The illustration on the left shows a negative
To check for a negative condition close all windows, outside doors, and fireplace
dampers. Turn on all exhausting appliances, including kitchen draft hoods,
clothes dryers, furnaces, bathroom vents, etc. Open all inner doors between
these appliances and the Power Shot.
Once all appliances are on and inner doors open, open the inlet air damper on
the Power Shot when the heater is not firing. Using your hand, check for air
movement. If air is being blown back into the room, a negative pressure condition
exists.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
AIR FOR COMBUSTION cant.
SOLUTION
CONDITION CAUSE
Seal vent joints
Burnt gas odor when
heater is operatinq Leaking vent
joints
Blocked vent Clear vent blockaQe
The majority of the complaints associated with the operation of the will likely be a direct result of
improper venting. If the customer complains of smelling burnt gas around the water heater, first
check for vent gases that may be leaking from the PVC joints or around the area between the blower
assembly and water heater. Seal all leaks with the high temperature silicone sealant provided.
Check for restrictions in the venting that may cause some spillage of burnt gas into the room and
check your draft, visually inspecting the vent termination for blockage, clearing blockage as
necessary.
Improper venting is also a major cause of sooting in water heaters. If you experience sooting with
the POWER SHO~, check that the inlet air damper swings freely and opens 1 1/4"when the blower
is running.
If water is dripping from the blower, condensate is the culprit
condensate tee, and pipe to drain. To correct the problem, install a
If the customer complains of nuisance pilot outage or pilot gas odor on standby, this may be due to a
lack of combustion air, or other appliance (exhaust fans, clothes dryers, etc.) creating a backdratt in
the FPS venting. In either case, install additional make-up air ducts.
Technical Information
Irving, Texas
17
@1995
A.D. Smith
Water ProductsCo.

FPS/FPSE/FPDTECHNICALTRAININGAND SERVICEWORKBOOK
AIR FOR COMBUSTION cont.
CONDITION CAUSE SOLUTION
Free air damperExcessive heat
build-up in PVC
venting
Inlet air damper not
opening completely
Blower does not run when
main burner fires Replace entire blower assembly
Wrong main burner
orifice size Install correct
orifice
Intermittent
fan cycling
without burner
operation
(Propane Only)
Build up of
pressure in the
main burner tube
between thermostat
gas valve and
solenoid qas valve
If cycling occurs
more than twice per hour,
see troubleshooting
procedures.
A malfunctioning vent damper may also cause excessive heat buildup in the PVC vent piping
unable to free the damper, replace the entire combustion control tee. If
If blower does not run when the main burner fires, replace the control box. Also check burner orifice
for correct size.
Intermittent cycling of the fan, without main burner operation, indicates a build-up of pressure in the
main burner tube between the thermostatic gas valve and solenoid gas valve.

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
AIR FOR COMBUSTION cont.
Negative
Pressure Diagnosing pilot outage complaints requires an examination of the environment in
which the heater is installed. Mechanical vent fans are the chief cause of
negative pressure. If the house is too tight, more air will be exhausted from the
structure than is being brought in from the outside, resulting in a negative
pressure condition. Fireplaces, furnaces, wind, and thermal stacking within the
house can also playa role in creating negative pressure conditions.
Negative pressure can result from air being backdrafted through the water heater
vent down into the combustion chamber, blowing out the pilot. This may happen
randomly because it may be a particular combination of appliances which cause
the condition.