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 switch. Switch should be open (no continuity) when 
blower is not operating. Replace switch if contacts are closed   
when blower is off.
 CHANGE  BACK ADV
ANCED
Blower Operation ErrorFault occurred 2 mins ago
Blower Prover Pressure Switch ma y
have failed closed. Check/replace
pressure switch.
Call a service professional:
Y our Company Name Here
(press [DOWN] for more.... )
• Confirm that blower runs during a call for heat.
•  If blower runs, confirm sensing tube is connected and clear of 
obstructions, blower port for sensing tube is clear of obstructions, 
and wire connections for blower prover switch are clean and tight.
•  If all above conditions are met, replace pressure switch.
 CHANGE  BACK ADV
ANCED
Blower Prover OpenFault occurred 2 mins ago
The blower prover switch remains
open after the blower has been
energized.
Call a service professional:
Your Company Name Her e
(press [DOWN] for more....)
•  If Blocked Intake error occurs before blower runs, make   sure 
pressure switch connections are clean and tight. Check pressure 
switch continuity/resistance. Switch   should be closed  
(continuity/0 ohms). Replace switch if open (no continuity).
•  If Blocked Intake error occurs when blower is running, check for 
restrictions in intake pipe, including intake air connection, outside 
termination, and inlet condensate drains (if installed).
•  Other possible causes: High wind conditions, excessive   negative 
air pressure in building.
 CHANGE  BACK ADV
ANCED
Blocked  Air IntakeFault occurred 2 mins ago
Restriction in air intake. Check 
intake pipe and termination for 
blockage.
Call a service professional:
Your Company Name Here
(press [DOWN] for more.... )
• Ensure wire connections to upper temperature probe are clean   
and tight.
•  Using a thermometer, check the water temperature of the heater.
•  Use a multi-meter and check for continuity between the two red 
wires of the upper temperature probe.
•  If the two red wires are open (no continuity) and water temperature 
is below 160°F, replace upper temperature probe.
•  If the water temperature exceeds 195°F, turn off electric power and 
gas supply and call Tech Support for further instructions.
 CHANGE  BACK ADV
ANCED
Energy Cut Out (ECO)Fault occurred 2 mins ago
Tank temperature is excessive. 
The water heater has been 
disabled.
Call a service professional:
Y our Company Name Here
(press [DOWN] for more.... )
• Confirm the water heater is full of water.
•  Confirm the powered anode wire connections are tight and free of 
debris or moisture (i.e. rust, solder, metal pipe shavings).
•  Confirm proper electrical ground to the water heater.
•  Inspect powered anode(s), clean/replace as needed.
 CHANGE  BACK ADV
ANCED
No W aterAlert:
Alert occurred 2 mins ago
No water detected by Powered 
Anode .
Call a service professional :
Yo ur Company Name Here
(press [DOWN] for more....)  
						

							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 heater should be drained if being shut down 
during freezing temperatures. See Features And Components 
on  page  7  for  the  location  of  the  water  heater  components 
described below.
Burn hazard.
Hot water discharge.
Keep  hands   clear  of  drain
valve  discharge.
To drain the water heater storage tank:
1.  Turn off the electrical supply to the water heater.
2.  Turn  off  the  gas  supply  at  the  Main  Gas  Shutoff  Valve  if  the 
water heater is going to be shut down for an extended period. 
3.  Ensure the cold water inlet valve is open.
4.  Open a nearby hot water faucet and let the water run until the 
water is no longer hot.
5.  Connect a hose to the water heater drain valve and terminate 
it to an adequate drain.
6.  Close the cold water inlet valve.
7.  Open the water heater drain valve and allow all the water to 
drain from the storage tank.
8.  Close  the  water  heater  drain  valve  when  all  water  in  the 
storage tank has drained.
9.  Close the hot water faucet opened in Step 4.
10.  If the water heater is going to be shut down for an extended 
period, the drain valve should be left open.
MAINTENANCE
GENERAL
Keep water heater area clear and free from combustible 
materials,  gasoline,  and  other  flammable  vapors  and 
liquids. See Locating The Water Heater on page 11.
Water  heater  maintenance  includes  periodic  tank 
flushing  and  cleaning,  and  removal  of  lime  scale.  The 
water  heater  should  be  inspected  and  adjusted  to 
maintain  proper  combustion.  See  Initial  Start  Up  on 
page  52.  A  periodic  inspection  of  the  venting  system 
should be made. Where used, water circulating pump(s) 
should  be  oiled  according  to  the  pump  manufacturers 
recommendations.
PRECAUTIONS
Do not operate the water heater if it has 
been exposed to or exhibits the following:
Exposed to flooding or water damage.
External damage.
Firing without water .
Sooting.
Do not operate the water heater until all corrective step s
have been made by a qualified service technician.
CAUTION
Never operate the water heater without first being certain 
it  is  filled  with  water  and  a  properly  sized  and  rated 
Temperature-Pressure Relief Valve is installed in the relief 
valve  opening  on  the  water  heater.  See  Temperature-
Pressure Relief Valve on page 15.
Explosion Hazard
Overheated water can caus e
water tank explosion.
Properly sized temperature and
pressure relief valve must be
installed in the opening provided.
Should  overheating  occur  or  the  gas  supply  fail  to  shut 
off, turn off the Main Gas Shutoff valve. See Figure 47 on 
page 39.  
						

							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 heater.
2.  The water heater must be drained, see Draining And Flushing on 
page 62, follow the instructions on how to drain the water heater.
3.  Remove outer cleanout access panel from lower side of the 
water heater jacket.
4.  Remove the cleanout cover from cleanout opening.
5.  Remove  lime,  scale  and/or  sediment  using  care  not  to 
damage the glass-lining.
6.  Install a new cleanout gasket if required.
7.  Reinstall  the  cleanout  cover.    Be  sure  to  draw  plate  up  tight 
by tightening screws securely.
8.  Close the water heater drain valve.
9.  Fill the water heater - see Filling The Water Heater on page 52.
10.  Turn  on  the  electrical  supply  to  place  the  water  heater  back 
in operation. See Initial Start Up on page 52.
11.  Allow the water heater to complete several heating cycles to 
ensure it is operating properly.
12.  Check for water leakage.
13.  Reinstall the cleanout access panel.
CHEMICAL LIME SCALE REMOVAL
To dissolve and remove more stubborn lime scale deposits, UN-
LIME® Professional Delimer should be used. 
UN-LIME® Professional Delimer is an easy to handle patented 
food  grade  acid  formulated  specifically  for  lime  scale  removal 
from  all  types  of  water  using  equipment.  Hydrochloric  base 
acids must not be used to delime the water heaters covered in 
this manual.
Follow  the  instructions  on  the  UN-LIME®  to  delime  the  water 
heater.
NOTE:  Call  the  parts  department  phone  number  on  the  back 
cover  of  this  manual  to  order  UN-LIME®  Professional  Delimer. 
See Table 20 for part numbers.
To Flush the tank perform the following steps:
1.  Turn off the electrical supply to the water heater.
2.  Ensure the cold water inlet valve is open.
3.  Open  a  nearby  hot  water  faucet  and  let  the  water  run  until 
the water is no longer hot. Then close the hot water faucet.
4.  Connect  a  hose  to  the  drain  valve  and  terminate  it  to  an 
adequate drain.
5.  Ensure the drain hose is secured before and during the entire 
flushing procedure. Flushing is performed with system water 
pressure applied to the water heater. 
6.  Open the water heater drain valve to flush the storage tank. 
7.  Flush the water heater storage tank to remove sediment and 
allow the water to flow until it runs clean.
8.  Close the water heater drain valve when flushing is completed.
9.  Remove the drain hose.
10.  Fill the water heater - see Filling The Water Heater on page 52.
11.  Turn  on  the  electrical  supply  to  place  the  water  heater  back 
in operation.
12.  Allow the water heater to complete several heating cycles to 
ensure it is operating properly.
FILLING THE WATER HEATER
See Filling The Water Heater on page 52.
SEDIMENT REMOVAL
Waterborne  impurities  consist  of  the  particles  of  soil  and  sand 
which  settle  out  and  form  a  layer  of  sediment  on  the  bottom  of 
the tank.
For  convenience,  sediment  removal  and  lime  scale  removal 
should be performed at the same time.
LIME SCALE REMOVAL
When  water  is  heated  dissolved  minerals  in  the  water  such  as 
calcium  and  magnesium  carbonate  (lime  scale)  become  less 
soluble.  As  the  water  temperature  rises  these  minerals  will 
precipitate or “fall out” of solution.
The  amount  of  lime  scale  released  from  water  is  in  direct 
proportion to water temperature and usage. The higher the water 
temperature or water usage, the more lime deposits are dropped 
out of the water.
Water  hardness  also  affects  lime  scale  accumulation.  With  the 
temperature and usage being the same, hard water will release 
more lime scale than softer water.
Lime  scale  reduces  heating  efficiency  as  it  accumulates  inside 
a  water  heater.  Heating  transfer  surfaces  become  coated  with 
lime  scale  deposits  which  increases  fuel  costs  to  operate  the 
water  heater.  Lime  scale  deposits  can  also  cause  rumbling 
and pounding noises as air molecules trapped in the lime scale 
escape when heated. Lime scale accumulation also reduces the 
life span of water heaters. For these reasons a regular schedule 
for deliming should be set up.
The  depth  of  lime  accumulation  in  the  bottom  of  the  water 
heater  should  be  measured  periodically.  Inspect  by  removing 
the  cleanout  cover  once  every  6  months  at  first.  Deliming 
maintenance  should  then  be  performed  based  on  the  time  it 
takes  for  1  inch  (2.5  cm)  of  lime  to  accumulate  in  the  bottom  of 
the water heater.
Sediment and lime scale removal may be accomplished manually 
through the cleanout opening furnished on the water heater, see 
Figure 55.   
						

							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  page  14.  The  Temperature-
Pressure Relief Valve is not intended for the constant relief of 
thermal expansion.
Temperature-Pressure  Relief  Valve  leakage  due  to  pressure 
build  up  in  a  closed  system  that  does  not  have  a  thermal 
expansion  tank  installed  is  not  covered  under  the  limited 
warranty.  Thermal  expansion  tanks  must  be  installed  on  all 
closed water systems.
DO NOT PLUG THE TEMPERATURE-PRESSURE RELIEF 
VALVE OPENING. THIS CAN CAUSE PROPERTY DAMAGE,  
SERIOUS INJURY OR DEATH.
Explosion Hazard
Te mperature-Pressure Relief  Valve
must comply with  ANSI Z21.22-
CSA 4.4 and  ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure .
Can cause serious injury or death.
VENT SYSTEM
Examine  the  vent  system  once  a  year.  Points  of  inspection  are 
as follows:
1. Check  for  obstructions  and/or  deterioration  of  the  intake  air 
and/or  vent  piping  and  the  intake  air  and  vent  terminations. 
Replace immediately where needed.
2.  The  debris  screens  in  the  intake  air  and  vent  terminations 
should  be  should  be  cleaned  of  foreign  material  and  soot. 
See Figure 22 on page 26.
NOTE:  Do  not  reach  inside  the  vent  termination  when  the 
heater is in operation.
3.  Check all vent system connections for leakage and repair or 
reseal as necessary.
TABLE 20
UN-LIME® PROFESSIONAL DELIMER
Part Number Description
9005416105 4 - 1 gallon (case)
9005417105 1 - 5 gallon
POWERED ANODE RODS
To  insure  a  long,  trouble-free  operating  life,  the  water  heaters 
covered  in  this  manual  are  factory  equipped  with  a  powered 
anode  system. The  anode  rods  are  of  a  permanent  design  and 
do not need replacing unless damaged. Inspection and cleaning 
should be performed once a year.
NOTE: Follow the instructions to drain the water heater storage 
tank  on  page  62  first.  Remove  the  powered  anodes  from  the 
water  heater  by  loosening  the  3/4"  NPT  bushing  that  forms  the 
top  of  the  anodes.  Do  not  disassemble  the  retaining  nut  and 
wire terminal from the top while installed in the water heater, the 
anode's  electrode  may  fall  inside  the  tank.  Remove  the  entire  
anode  rod  from  the  water  heater  prior  to  inspection.  Clean  the 
anode rods with a soft cloth and reinstall. Follow the instructions 
for filling the water heater on page 52 when finished.
DRAIN VALVE AND ACCESS PANELS
The  water  heaters  covered  in  this  manual  are  equipped  with 
a  drain  valve,  see  Features  And  Components  on  page  7  for 
location.  The  water  heaters  covered  in  this  manual  are  also 
equipped  with  a  cleanout  opening  for  sediment  and  lime  scale 
removal. See Figure 55 on page 63.
TEMPERATURE-PRESSURE RELIEF VALVE TEST
Burn hazard.
Hot water discharge. Keep clear of  Temperature-
Pressure Relief V alve
discharge outlet.
It  is  recommended  that  the  Temperature-Pressure  Relief  Valve 
should  be  checked  to  ensure  that  it  is  in  operating  condition 
every 6 months.
When checking the Temperature-Pressure Relief Valve operation, 
make sure that (1) no one is in front of or around the outlet of the 
Temperature-Pressure  Relief  Valve  discharge  line,  and  (2)  that 
the water discharge will not cause any property damage, as the 
water may be extremely hot. Use care when operating valve as 
the valve may be hot.
To  check  the  relief  valve,  lift  the  lever  at  the  end  of  the  valve 
several times, see Figure 56. The valve should seat properly and 
operate freely.
If  after  manually  operating  the  valve,  it  fails  to  completely  reset 
and  continues  to  release  water,  immediately  close  the  cold 
water  inlet  to  the  water  heater  and  drain  the  water  heater,  see 
Draining  And  Flushing  on  page  62.  Replace  the  Temperature-
Pressure  Relief  Valve  with  a  properly  rated/sized  new  one,  see 
Temperature-Pressure  Relief  Valve  on  page  15  for  instructions 
on replacement.  
						

							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 Orange6 White/Gree n
24VAC24VAC12VD C5VDCDgnd
9 Whit eCCB J1
HIGH Voltage In8 Blac k7 Red6 Gree n
3 Black4 White5
2 Red1
Neutra lL1Pump CommonPump NO
AUX NOAUX CommonAUX NCPE
CCB J13
Display / AI N
GreenYellow
Splice
BlueBlue
CCB J14 
Limit String
1 Blue2 Green3 Yellow4 Blac k6 Black7 Red8 Blac k9 Red10 Blac k11 Red12 Blac k
AnodeDgndFlame Ro dCondensat e
Gas PSGas V SwitchGas V 24V24V Rtn
Condensat eGas PSGas V Switch
1 Red2 Blac k
CCB J6
120V Ou t
Neutral120 to Spar k
Gas Pressure
Switc h
RedBlackRedBlack
Upper Temperature 
Probe / EC O
1 Red2 Blac kCCB J9
Upper Probe
EC OThermistor
4 Re d3 Blac kECOThermistor
1 Blac k2 BlackCCB J1 0
Lower Prob e
ThermistorThermistorBlackBlack
Lower 
Temperature  
Probe
Gas Valv e
Ground Ba r
Hot
Neutra l
Blue
Brown
Spar k
Module
120V
Neutra l
L1
Neutral
Protective  
Earth
= multi-conductor power limited cable,  18AWG 80°C 300V UL category QPTZ
Connects 
to burner  
bol t
= Spark ignition wire, 220°C  25kVDC 8mm EMI suppression
Spark
Rod
Anod e
Ro d
Flame 
Ro d
Anod e
Ro d
Splice
CCB J5
VFD LOGI C1 Blue3 White/Blac k4 Yellow5 White/Gree n6 White7 White/Yellow
24Vureg
Speed f-backDgnd0 to 10V
24V enabl eDrive enable
1 Blue2 White/Gree n3 Yellow
BLOWER
FEEDBAC K24VuregDgndSpeed f-back
White/Gree n
VFD
1 White/Gree n2 White/Black3 White/YellowVFD 
LOGIC
4 Whit e
Dgnd0 to 10VDrive enable24V enable
1 Black2 Green3 Whit e120V to VF D
CCB J17
Low Voltage FieldNo factory 
connection s
Enable/Disabl e
Switch
P1-1W1-RedP1-2W2-GreenP1-3W3-White/Brow nP1-4W4-White/Blue
CCB J12
Configuration Ke ySDA (data)SCL (data)Write protectP1-5P1-6W5-White/Orang e+5VDgndConfiguration 
Key
Outlet PressureSwitch
1 Blac k2 Red
CCB J1 5
Pressure 
Switches
Inlet return / Prover powerOutlet return / Inlet po wer
4 Gree n3 WhiteOutlet powe rProver return
Inlet Pressure
Switch
Blower Prove r
Pressure
Switch
Displa y
Display / AI N
= 18AWG AWM wire 105°C 600V UL style 1015.  Flame rod wire = 200°C\
 300V UL 1180 .  
						

							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  WITH TOGGLE SWITC H
FIELD SUPPLIED  TEMPERATURE
CONTROL  INSTALLED IN  THE
CIRCULA TING LOOP  RETURN LINE
DISHW
ASHER
T OGGLE
SWITCH
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 60  
						

							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 Mixing Valves on page 14.
2.  See Dishwashing Machines on page 14.
3.  See Temperature-Pressure Relief Valve on page 15.ONE WA TER HEA TER, SINGLE TEMPERA TURE
WITH B UILDING RECIR CULATION
ONE WA
TER HEA TER, SINGLE TEMPERA TURE
WITH B UILDING RECIR CULATION
NOTES:
1. Preferred piping method .
2.  The temperature and pressure relief valve setting shall not exceed press\
ure rating of any component in the system .3. Service valves are shown for servicing unit. Howeve r, local codes shall govern their usage.
LEGEND
TEMPERAT URE & 
PRESSURE RELIEF  VALVEPRESSURE RELIEF  VALVECIRCULA TING PUMP
TEMPERATURE CONTRO L 
PROB EDRAINFULL PORT BALL  VA LVE
TEMPERAT URE GAGEWATER FLOW SWITCH
CHECK VA
LVE
WARNING : THIS DR AWING SHOWS SUGGESTED  
PIPING CONFIGURA TION AND OTHER DEVICES; 
CHECK WITH LOCAL CODES  AND ORDINANCES 
FOR  ADDITIONAL REQUIREMENTS.ANY MA TERIAL, COMPONEN T OR VENDOR CHANGE 
MUST  HAVE PRIOR  APPROVAL BY  THE  APPLICABLE 
PRODUCT  ENGINEERING DEPA RTMENT.
HOT  WATER 
TO  FIXTURES
PIPE T&P TO
OPEN DRAIN
FINISHED FLOOR HOT WATE
R
RETURN
COLD WATER
SUPPLY
EXPANSION
TANK  
						

							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 Mixing Valves on page 14.
2.  See Dishwashing Machines on page 14.
3.  See Temperature-Pressure Relief Valve on page 15.
ONE WATER HEATER, TWO TEMPERATURE
WITH HIGH TEMPERAURE LOOP RECIRCULATION
WITH BUILDING RECIRCULATIONNOTES:
1. Preferred piping method .
2.  The temperature and pressure relief valve setting shall not exceed press\
ure rating of any component in the system .
3.  Service valves are shown for servicing unit. Howeve r, local codes shall govern their usage.
LEGEND
TEMPERAT URE & 
PRESSURE RELIEF  VALVEPRESSURE RELIEF  VALVECIRCULA TING PUMP
TEMPERATURE CONTRO L 
PROB EDRAINFULL PORT BALL  VA LVE
MIXING VA LVE
TEMPERAT URE GAGEWATER FLOW SWITCH
CHECK VA
LVE
WARNING : THIS DRA WING SHOWS SUGGESTED  
PIPING CONFIGURA TION AND OTHER DEVICES; 
CHECK WITH LOCAL CODES  AND ORDINANCES 
FOR  ADDITIONAL REQUIREMENTS.ANY MA TERIAL, COMPONEN T OR VENDOR CHANGE 
MUST  HAVE PRIOR  APPROVAL BY  THE  APPLICABLE 
PRODUCT  ENGINEERING DEPA RTMENT .
FINISHED FLOOR HOT WATE
R
RETURN OUTLET
HOT
TEMPERED WATER
RETURN TEMPERED
WATER
OUTLET
PIPE T&P TO
OPEN DRAIN
COLD WATER
SUPPLY
COLD
EXPANSION
TANK  
						

							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 Mixing Valves on page 14.
2.  See Dishwashing Machines on page 14.
3.  See Temperature-Pressure Relief Valve on page 15.
ONE WA TER HEA TER, SINGLE TEMPERA TURE
WITH VERTICAL ST ORAGE T ANK FOR CED RECIR CULATION
WITH B UILDING RECIR CULATIONNOTES:
1. Preferred piping method.
2.  The temperature and pressure relief valve setting shall not exceed press\
ure rating of any component in the system.
3.  Service valves are shown for servicing unit. Howeve r, local codes shall govern their usage.
4.  The tank temperature control should be wired to and control the pump bet\
ween the water heater(s) and the storage tank(s).
5.  The water heater ’s operating thermostat should be set 5 degrees F higher than the tank tem\
perature control.
LEGEND
TEMPERAT URE & 
PRESSURE RELIEF  VALVEPRESSURE RELIEF  VALVECIRCULA TING PUMP
TEMPERA TURE CONTRO L 
PROB EDRAINFULL PORT BALL  VA LVE
TEMPERAT URE GAGEWATER FLOW SWITC H
CHECK VA
LVE
WARNING : THIS DRA WING SHOWS SUGGESTED  
PIPING CONFIGURA TION AND OTHER DEVICES; 
CHECK WITH LOCAL  CODES AND ORDINANCES 
FOR  ADDITIONAL  REQUIREMENTS.ANY MA TERIAL, COMPONEN T OR VENDOR CHANGE  
MUST  HAVE PRIOR  APPROVAL BY THE  APPLICABLE 
PRODUCT  ENGINEERING DEP ARTMENT .
FINISHED 
FLOOR HOT WATER
RETURN
PIPE T&P TO
OPEN DRAIN
COLD WATER
SUPPLY
HOT WATER
TO FIXTURE
S
ALT. COLD WATER
CONNECTION
EXPANSION
TANK
STORAGE T ANK