American Water Heater High Efficiency Commercial Gas HCG Series AHCG3 119T 300 THRU AHCG3 119T 500 Series 200 201 User Manual

61
FAULT AND ALERT MESSAGES (CONT)
Call the technical support phone number listed on the back cover for further technical assistance or to locate a qualified service agent 
in your area.
POSSIBLE CAUSES - CHECK/REPAIRDISPLAYED FAULT/ALERT MESSAGE
• Ensure excessive wind is not pressurizing the intake air or   
exhaust pipe.
•  Confirm wire connections of the blower prover switch are  
clean, tight, and not jumped/shorted.
•  Use multi-meter to check continuity/resistance of blower   prover 
pressure...

62
MAINTENANCE SCHEDULE
TABLE 19
COMPONENTOPERATION INTERVALREQUIRED
Tank Sediment 
Removal Semi Annually
Flushing
Tank Lime Scale 
Removal Semi Annually
UN-LIME®
Anode Rods Inspection 
Cleaning Annually
Clean Scale 
Deposits
T&P Valve Test OperationSemi Annually Test
Vent System InspectionAnnuallyTermination 
Screens Clean
Reseal/Repair
DRAINING AND FLUSHING
It  is  recommended  that  the  water  heater  storage  tank  be 
drained  and  flushed  every  6  months  to  reduce  sediment 
buildup. The water...

63
TANK
CLEANOUT OPENING
CLEANOUT COVER CLEANOUT
GASKET CLEANOUT
ACCESS P ANEL
Figure 55
MANUAL LIME SCALE REMOVAL
NOTE: Contact your local distributor or call the parts department 
phone number on the back cover of this manual to order a new 
cleanout gasket. Have the new gasket available before removing 
the cleanout cover.
The  cleanout  opening  is  shown  in  Figure  55.  To  remove  lime 
scale manually through the cleanout opening proceed as follows:
1.  Turn off the electrical supply to the water...

64
DISCHARGE PIPETEMPERA
TURE-PRESSURE
RELIEF VA LVE
Figure 56
If  the  Temperature-Pressure  Relief  Valve  on  the  water  heater 
weeps  or  discharges  periodically,  this  may  be  due  to  thermal 
expansion.
NOTE: Excessive water pressure is the most common cause 
of  Temperature-Pressure  Relief  Valve  leakage.  Excessive 
water  system  pressure  is  most  often  caused  by  "thermal 
expansion"  in  a  "closed  system."  See  Thermal  Expansion 
and  Closed  Water  Systems  on...

65
DIAGRAMS
CCB - CENTRAL CONTROL BOARD LAYOUT
CCB (CENTRAL CONTROL BOARD)
11
12 1
J16
J5 J3
J13
J4
J17
J10
J9
J14
J15
J1 J6 J12
1
1 1
1
1
1
1
1
1
1 1 1
2
2 2
2
2
2 2
2
2
2
2
23
3 3
3
3
3
3
3
3
3
3 4
4 4
4 4
4
4
4
4 4
4 5
5
5
5
5
5
6 6
6
6
6 6
7
7
8
8
8 9
9
7 10
8
Figure 57  

66
WIRING DIAGRAM
Figure 58
Splice
Splice
Green
Green
Ferrite 
Bead
Transforme r
Secondar y
White / Re d
White / BlueTransforme r
PrimaryBlack
Whit eTransforme r
Power
Supply J21 Blue3 Orange4 White/Gree nPower
Supply J12 Whit e3 BlackPower 
Supply
Central Control Board
(CCB)
Blowe r
8 Whit e
Field Bo x
HIGH Voltag e
J1
7 Blac k6 Red5 Green4 Whit e3 Black2 RedGreen
Neutra lL1Aux 2 CommonAux 2 NO
Aux 1 NOAux 1 Commo n
Aux 1 NCOPENPE
Junction Bo
x
CCB J16
Low Voltage In
1 White/Re d2 White/Blue4 Blue5...

67
CIRCULATION PUMP WIRING DIAGRAMS
CIRCULATING PUMP WIRING DIAGRAM
STORAGE  TANK OR BUILDING RECIRCULA TION
FIELD SUPPLIED TEMPERATURE CONTROL
INST ALLED IN  THE STORAGE  TANK
OR CIRCULA TING LOOP RETURN LINE
CIRC
PUMP
MOT OR
L1 HOT
L2 NEUTRAL 120 VA
C
POWER
NOTE: USE SEP ARATE 120 V AC POWER
SUPPL Y FOR PUMP  CIRCUIT. DO NOT
SHARE POWER WITH  APPLIANCE AS THIS
MA Y CAUSE ELECTRICAL  LINE NOISE AND
LEAD  TO ERRA TIC CONTROL SYSTEM
OPERA TION. 
Figure 59
CIRCULA TING PUMP WIRING DIAGRAM
DISHWASHER LOOP...

68
4. See Closed Systems and Thermal Expansion on page 14.
5.  See Water Line Connections on page 41.
6.  If a pump is being installed between a water heater and storage tank or on a building 
recirculation loop wire according to Figure 59 on page 67.
7.  If  a  pump  is  being  installed  in  a  recirculation  loop  between  the  water  heater  and  a 
commercial dishwasher wire according to Figure 60 on page 67.
WATER PIPING DIAGRAMSBefore installation of water piping review the following:
1. See...

69
4. See Closed Systems and Thermal Expansion on page 14.
5.  See Water Line Connections on page 41.
6.  If a pump is being installed between a water heater and storage tank or on a building 
recirculation loop wire according to Figure 59 on page 67.
7.  If  a  pump  is  being  installed  in  a  recirculation  loop  between  the  water  heater  and  a 
commercial dishwasher wire according to Figure 60 on page 67.
WATER PIPING DIAGRAMSBefore installation of water piping review the following:
1. See...

70
4. See Closed Systems and Thermal Expansion on page 14.
5.  See Water Line Connections on page 41.
6.  If a pump is being installed between a water heater and storage tank or on a building 
recirculation loop wire according to Figure 59 on page 67.
7.  If  a  pump  is  being  installed  in  a  recirculation  loop  between  the  water  heater  and  a 
commercial dishwasher wire according to Figure 60 on page 67.
WATER PIPING DIAGRAMSBefore installation of water piping review the following:
1. See...