A.O. Smith LB-LW- 500, 750, 1000 User Manual

WIRING/HARNESS & PROBES

See page 12

PROPANE GAS TRAIN ASSEMBLY

See pages 8-10

JACKET/FRAME ASSEMBLY

See page 4

PSD-3-153

COMMERCIAL POWER BURNER BOILER

REPLACEMENT PARTS LIST

COPPER BOILERS FOR HYDRONIC

HEATING & HOT WATER SUPPLY

LEGEND MODELS LB/LW: 500, 750 & 1000

SERIES: 300 - 301

NATURAL GAS

TRAIN/BLOWER

ASSEMBLY

See pages 5-7

WATERWAYS &

COMBUSTION

CHAMBER

See page 2

CONTROL BOARD

See page 11

BY-PASS

See pages 8-10

EXHAUST & DRAIN

ASSEMBLY
See page 3

WATER INLET

See page 3

A.O. SMITH WATER PRODUCTS CO., INC.

5621 W. 115TH STREET • ALSIP, ILLINOIS 60803

Phone: [phone] • Fax: [phone]

PRINTED IN U.S.A. 0403 211691-000

Website: www.hotwater.com

1

LB/LW WATERWAYS & COMBUSTION CHAMBER PARTS LIST

Item Description Model 500 Model 750 Model 1000

1 ................ Bracket ........................................................................................ 191602........................191602 .................... 191602

2 ................ Burner and Cone Assembly .......................................................191850 ...................... 191850-1 ................ 191850-2

3 ................ Combustion Chamber Assembly ............................................ 191529-2 .................... 191529-3................ 192129-1

4 ................ Connector, Hose......................................................................... 191765........................191765....................191765

5 ................ Coupling, Flexible w/Gasket ....................................................... 191780........................191780.................. 191780-1

6 ................ Cover, Outer ................................................................................ 210408........................210408....................210404

7 ................ Gasket, Outer ............................................................................ 211594-1 .................... 211594-1................ 211594-1

8 ................ Gasket, Burner.......................................................................... 191564-1.................... 191564-1................ 191564-1

9 ................ Gasket, Inner............................................................................... 211594........................211594....................211594

10 ................ Housing Assembly ..................................................................... 211742...................... 211742-1................ 211742-2

11 ................ Ignitor .......................................................................................... 192334........................ 192334....................192334

12 ................ Insulation, Burner ....................................................................... 191618........................ 191618....................191618

13 ................ Nut, Manifold ............................................................................... 191555........................

14 ................ O-Ring ......................................................................................... 191556........................191556.................. 191556-2

15 ................ Probe, Outlet Temp./ECO ........................................................... 210572........................210572.................... 210572

16 ................ Probe, Inlet Temp. ...................................................................... 210571........................ 210571.................... 210571

17 ................ Screw, Machine #8-32, 3/8" Long, SST ..................................... 210444........................210444 .................... 210444

18 ................ Screw, Machine #8-32, 1" Long SST ......................................... 191770........................191770 .................... 191770

*19................ Sealer, Silicone Hi-Temp ......................................................... 191482-1.................... 191482-1................ 191482-1

20 ................ Sensor, Flame ............................................................................ 210421........................210421 .................... 210421

21 ................ Spacer Ring ................................................................................ 191554........................191554 .................. 191554-1

22 ................ Switch, Safety Flow ..................................................................... 211480........................211480....................211480

23 ................ Tee Assembly ............................................................................. 191583........................191583.................... 192387

24 ................ Tube Assembly, Primary (LW Models) ...................................... 210900........................210900....................192388

24 ................ Tube Assembly, Primary (LB Models) .......................................

210901........................210901.................... 192225

25 ................ Tube Assembly, Outlet ............................................................... 210425........................ 210425.................... 210426

26 ................ Tube Assembly, Secondary ....................................................... 210912........................210912 .................... 192386

27 ................ Washer, Flat #8 SST................................................................... 191768........................191768....................191768

28 ................ Restrictor-Air, Top Cover .......................................................... 191926-1.................... 191926-1................ 191926-1

*Item Not Illustrated.

Note: Replacement housing assemblies (item 10) are currently all steel
type. When replacing the housing assembly both the inner gasket
(item 9) and outer gasket (item 7) must also be replaced. In addition,
high temperature silicone sealant (item 19) is required to fix the gaskets
to the surfaces.

The T ub Replacement Kit is available for replacing housing assemblies.
When ordering use p/n 211742 for LB/LW 500 models, p/n 211742-1 for
LB/LW 750 models and p/n 211742-2 for LB/LW 1000 models.

191555.................. 191555-1

LW Models

LB Models

2

LB/LW EXHAUST, DRAIN & WATER INLET ASSEMBLY PARTS LIST

Item Description Model 500 Model 750 Model 1000

1 ................ Clamp, Hose (Large) ......................................................................... 191794-1..............191794-1 ............ 191794-1

2 ................ Clamp, Hose (Small) ......................................................................... 191794-3..............191794-3 ............ 191794-3

3 ................ Nut, Hex .............................................................................................. 191817-1..............191817-1 ............ 191817-1

5 ................ Drain, Flange ....................................................................................... 191620 ................. 191620 ................ 191620

6 ................ Drain, Flange Assembly ...................................................................... 191625 ................. 191625 ................ 191625

7 ................ Elbow ....................................................................................................191664................. 191664 ................191664

9 ................ Gasket, Drain ....................................................................................... 191622................. 191622 ................ 191622

10 ............... Gasket, Vent ......................................................................................... 191683................. 191683 .............. 191683-1

11 ............... Nipple ................................................................................................. 20373-15..............20373-15 ............ 20373-18

12 ............... Nut, Hex 1/4" (Serrated) ....................................................................... 210226................. 210226 ................210226

13 ............... O-Ring ................................................................................................ 191556-1 ..............191556-1 ............ 191556-1

14 ............... Plate, Drain Seal ..................................................................................191626 ................. 191626 ................ 191626

15 ............... Pump Assembly, Circulator (LW Models) ...........................................

16 ............... Tube Assembly, Inlet (LW Models) ................................................... 210897-1 ..............210897-2 .............. 192308

17 ............... Tube Assembly, Primary (LB Models) ................................................ 210901................. 210901 ................192225

18 ............... Tube Assembly, Primary (LW Models)................................................210900................. 210900 ................192388

19 ............... Tubing, Condensate .........................................................................191746-24 ........... 191746-24 .......... 191746-24

20 ............... Tubing, Pressure .............................................................................. 191562-26 ........... 191562-26 .......... 191562-26

21 ............... U-Bolt Assembly .................................................................................. 191938................. 191938 ................191938

22 ............... Valve Drain ............................................................................................26273 ................... 26273 .................. 26273

23 ............... Vent Assembly ..................................................................................... 210499................. 210499 ................210494

24 ............... Vent Flange ........................................................................................ 191685-4 ..............191685-4 ............ 191685-5

25 ............... Washer, Plain ..................................................................................... 76820-18 ..............76820-18 ............ 76820-18

26 ............... Vent Support, Bracket (1000 Model Only) ............................................ - - - - - .................... - - - - -.................. 192194

27 ............... Vent, Restricting Ring (500 Model Only) ........................................... 191923-2

28 ............... Vent, Restricting Ring (Series 301 LP)................................................ - - - - - ....................- - - - -................ 191923-1

211611................. 211612 ................ 211538

.................- - - - -................... - - - - -

3

LB/LW JACKET/FRAME ASSEMBLY

Item Description Model 500 Model 750 Model 1000

1 .......... Bolt, Machine 5/16" - 18 ..............................................................191358-1 ................... 191358-1................... 191358-2

2 .......... Control Panel Assembly ............................................................. 210601-1 ................... 210601-1.....................210601

3 .......... Display Board ............................................................................... 210219 ....................... 210219 ...................... 210219

4 .......... Frame Assembly .......................................................................... 210495 ..................... 210495-1................... 210501-1

5 .......... Gasket, Dispaly ............................................................................ 210130 ....................... 210130 ...................... 210130

6 .......... Grommet ....................................................................................... 97591 ......................... 97591......................... 97591

7 .......... Handle .......................................................................................... 191802 ....................... 191802 ...................... 191802

8 .......... Junction Box As sembly ............................................................... 190438-1 ................... 190438-1................... 190438-1

9 .......... Junction Box Cover ........................................................................ 2233 ........................... 2233 ........................... 2233

10 ......... Label, Control Panel .................................................................... 210561 ....................... 210561 .................... 210561-1

11 ......... Locknut, Star................................................................................... 1953 ........................... 1953 ........................... 1953

12 ......... Locknut #6 -32 .............................................................................. 210207 ....................... 210207 ...................... 210207

13 ......... Nipple, Chase

14 ......... Nut, Lock Hex 5/16" - 18 (1000 Model Only) ................................. - - - - -.......................... - - - - - ......................... 97896

15 ......... Panel Assembly, Left Side ..........................................................191796-1 ................... 191796-1................... 191796-3

16 ......... Panel Assembly, Right Side ........................................................ 191796 ....................... 191796 .................... 191796-2

17 ......... Panel, Lower Front....................................................................... 191805 ....................... 191805 .................... 191805-1

18 ......... Panel, Rear (Natural) ................................................................... 191748 ..................... 191748-1.....................192191

........... Panel Rear (Propane) .................................................................. 191748 ..................... 191748-4.....................210020

19 ......... Panel, Top Cover.......................................................................... 191609 ....................... 191609 .................... 191609-1

20 ......... Plate, Rear Cover (1000 Model Only) ............................................- - - - -.......................... - - - - - ........................ 210214

21 ......... Screw, Hex Head 5/16" ................................................................ 210125 ....................... 210125 ...................... 210125

22 ......... Screw, Hex Head #6-32 ............................................................... 210206 ....................... 210206 ...................... 210206

23 ......... Switch, Blower Prover .................................................................. 191666 .......................191666

24 ......... Switch, Blocked Flue .................................................................... 191667 ....................... 191667 ...................... 191667

25 ......... Switch, Rocker .............................................................................. 191665 ..................... 191665-1................... 191665-1

26 ......... Support Bracket (Propane Only)....................................................- - - - -......................... 210019 ...................... 210017

27 ......... Transformer (75VA) ...................................................................... 192528 ....................... 192528 ....................... - - - - -

........... Transformer (100VA) .....................................................................- - - - -.......................... - - - - - ........................ 210449

28 ......... U-Bolt Assembly (Water way) ...................................................... 191938 ....................... 191938 ...................... 191938

29 ......... Washer, Flat ................................................................................. 191359 ....................... 191359 ...................... 191359

30 ......... Washer, Lock ............................................................................... 191480 ....................... 191480 ...................... 191480

31 ......... Switch, Relay ..................................................................................- - - - -.........................211546 ...................... 211546

32 ......... Blower Speed Control .................................................................. 191922 ........................ - - - - - ......................... - - - - -

33 ......... Control Bracket Assembly ........................................................... 210902 ..................... 210902-3................... 192167-2

............................................................................... 41994 ......................... 41994......................... 41994

...................... 191666

4

LB/LW NATURAL GAS TRAIN/BLOWER ASSEMBLY- MODEL 500

Item Description Model 500

1 ....Blower ............................................................ 211613

2 ....Blower Adapter Assembly ............................. 191645

3 ....Blower Manifold Assembly ............................ 191832

*4 ....Bracket, Blower .............................................. 191773

*5 ....Clamp, Hose ................................................. 191794

6 ....Elbow, 1"............................................................. 1630

7 ....Elbow, Union 1" .............................................. 2482-1

8 ....Elbow, Street 1".............................................. 190763

9 ....F lange, Obs ervation P ort............................... 191573

10 ....Gasket, Blower .............................................. 191623

11 ....Gasket, Burner ............................................... 191564

12 .... G asket, Manifo ld ............................................ 191565

13 ....Gasket, Port (1/8" Thick) ................................ 191576

14 ....Manifold Assembly ........................................ 191610

15 ....Nipple, Close 1/8" ...................................... 191147-1

16 ....Nipple, Close Stainless ................................ 191772

17 ....Nipple, Tapped ........................................... 86397-11

18 ....Nipple, 1" x 9 1/2"............................................. 86397

19 ....Nipple, 1" x 2" ......................................................1177

19A ....Nipple, Pipe 1"x2 1/2" .........................................1179

19B ....Nipple, Pipe 1"x14 1/2".................................86397-6

*Item Not Illustrated.

Item Description Model 500

20 ....Nut, Hex 1/4" ..................................................... 170272

21 ....Orifice, Air .......................................................... 192737

22 ....Orifice, Union (See Orifice Table Below)

23 ....Plug, 1/8" Pipe .................................................... 3348

24 ....Port, Observation Lower ................................... 191572

25 ....Port, Observation Upper ................................. 191572-1

26 ....Screen, Air Inlet................................................. 192041

27 ....Screw, Cap 1/4" .............................................. 190960-2

28 ....Sre w , F l athead #8-32 x 1/2" ............................. 191542

29 ....Screw, Flat head #8-3 2 x 3/ 4" ......................... 191542-1

30 ....Switch, Low Pressure .................................... 191149-1

31 ....Tee, 1/8" ............................................................. 40119

*32 ....Tee, Union ........................................................ 191633

*33 ....Tubing, Pressure.............................................. 191562

*34 ....U-Bolt Assembly ............................................. 191938-1

35 ....Valve, Main Gas ................................................ 191956

36 ....Washer, Lock 1/4" .............................................. 1006

37 .... Sh utter, B lower ................................................. 211694

38 ....Flange, Shutter ................................................. 211695

39 ....Manual Firing Valve .......................................... 3423-4

DETAIL BACK VIEW

Note: Manual firing valve (item 43) used on

US models made on or after 6/1/02.

LEGEND ORIFICE TABLE

Model Natural Gas Size (In.) Elevation (Ft.)

LB & LW-500 191884-0 0.391 0 - 2000
LB & LW-500 191884-1 0.384 2001 - 3000
LB & LW-500 191884-2 0.374 3001 - 4000

5

LB/LW NATURAL GAS TRAIN/BLOWER ASSEMBLY- MODEL 750

Item Description Model 750

1 ..... Blower ............................................................. 211614

2 ..... Blower Adapter Assembly .............................. 191645

3 ..... Blower Manifold Assembly ............................. 191832

*4 ..... Bracket, Blower ............................................... 191773

*5 ..... Clamp, Hose ...................................................191794

6 ..... Elbow, 1" ........................................................... 1630

7 ..... Face Bushing 1"x1 1/4" ................................... 99376

*9 ..... Flange, Observation Port ................................ 191573

10 ..... Gasket, Blower................................................ 191623

*1 1 ..... Gasket, Burner ................................................ 191564

12 ..... Gasket, Mani fold ............................................. 191565

*13 ..... Gasket, Port (1/8" Thick) ............................... 191576-1

*1 4 ..... Gasket, Port (1/16" Thick) ............................... 191576

15 ..... Manifold Assembly ......................................... 191610

16 ..... Nipple, Close 1/8" ......................................... 191147-1

17 ..... Nipple, Close Stainless ................................. 191772

18 ..... Nipple, 1x4 1/2" with Tap .............................. 86397-14

19 ..... Nipple, 1" x 9 1/2" ............................................. 86397

20 ..... Nipple, 1" x 2" .................................................... 1177

20A... Nipple, 1"x15 1/2" ......................................... 86397-13

20B... Nipple, 1 1/4" x 2" .......................................... 86505-29

20C .. Nipple, 1"xClose ............................................... 1342

20 D .. Nipple, 1"x4" ................................................... 86397-7

*Item Not Illustrated.

Item Description Model 750

21 ....Nut, Hex 1/4" ..................................................... 170272

22 ....Orifice, Air ........................................................ 192737-1

23 ....Orifice, Union (See Orifice Table Below)

24 ....Plug, 1/8" Pipe .................................................... 3348

*25 ....Port, Observation Lower ................................... 191572

*26 ....Port, Observation Upper ................................. 191572-1

27 ....Screen, Air Inlet.................................................192041

*28 ....Screw, Cap 1/4" .............................................. 190960-2

*29 ....S re w , Fl a t h ea d #8-32 x 1/2" ............................. 191542

*3 0 ....Screw, F lath ead # 8-32 x 3/4" ......................... 191542-1

31 ....Switch, Low Pressure .................................... 191149-1

33 ....Tee, 1/8" ............................................................. 40119

*34 ....Tee, Union ........................................................ 191633

*35 ....Tubing, Pressure .............................................. 191562

*36 ....Tubing, Top Cover Assembly ........................... 191925

*37 ....U-Bolt Assembly ............................................. 191938-1

38 ....Valve, Main Gas ............................................... 78481-3

*39 ....Washer, Lock 1/4" .............................................. 1006

40 ....Valve, Solenoid Gas ......................................... 192189

41 ....Shutter, Blower ................................................. 211694

42 ....Flange, Shutter ................................................. 211695

43 ....Manual Firing Valve .......................................... 3423-4

DETAIL BACK VIEW

LEGEND ORIFICE TABLE

for boilers built on or after 6/01/02.

Model Natural Gas Size (In.) Elevation (Ft.)

LB & LW-750 191884-11 0.464 0 - 2000
LB & LW-750 191884-12 0.450 2001 - 3000
LB & LW-750 191884-13 0.443 3001 - 4000

Note: Manual firing valve (item 43) used on
US models made on or after 6/1/02.

LEGEND ORIFICE TABLE

Model Natural Gas Size (In.) Elevation (Ft.)

LB & LW-750 191884-3 0.484 0 - 2000
LB & LW-750 191884-5 0.469 2001 - 3000
LB & LW-750 191884-7 0.461 3001 - 4000

6

LB/LW NATURAL GAS TRAIN/BLOWER ASSEMBLY - MODEL 1000

Item Description Model 1000

1 .....Blower ...............................................................192195

2 .....Blower Adapter Assembly .............................. 192215-1

3 .....Blower Manifold Assembly ............................... 192217

4 .....Bracket, Blower ................................................. 210214

5 .....Clamp, Hose .................................................. 191794-3

6 .....Elbow, 1-1/4" ..................................................... 192216

7 .....Elbow, Union 1-1/4" ......................................... 86506-1

8 .....Flanged Observation Port ................................ 191573

9 .....Gasket, Blower Air Inlet .................................... 192213

10 ....Gasket, Burner .................................................. 191564

11 ....Gaske t, Mani fold ............................................... 191565

12 ....Gasket, Port (1/8" Thick) ................................... 191576

13 ....Nut, Hex 1/4", Serrated ..................................... 210226

14 ....Manifold Assembly - Air/Gas ............................ 192309

15 ....Nipple, Close 1/8" .......................................... 191147-3

16 ....Nipple, Close Stainless ................................. 191772-1

17 ....Nipple, Tapped ................................................ 86505-3

18 ....Nipple, 1-1/4" x 38-1/2" ................................... 86505-28

19 ....Nipple, 1-1/4" x 28-3/4" ................................... 86505-27

20 ....Nipple, 1-1/4" x 2" .............................................. 86505

21 ....Nipple, 1-1/4" x 3" ............................................ 86505-2

22 ....Nipple, 1-1/4" x 4" ............................................ 86505-6

23 ....Nut, Hex 1/4" ................................................... 191817-1

*Item Not Illustrated.

Item Description Model 1000

24 ....Orifice, Air (Series 300 - Nat. Gas)................. 192737-3

24 ....Orifice, Air (Series 30211 - L.P. Gas) ............ 192737-2

25 ....Orifice, Union (See Orifice Table Below)

26 ....Plug, 1/8" Pipe .................................................... 3348

27 ....Port, Observation Lower ................................... 191572

28 ....Port, Observation Upper ................................. 191572-1

29 ....Screen, Air Inlet............................................... 192220-1

30 ....Screw, Cap 1/4" .............................................. 190960-2

31 ....Srew, Flathead #8-32 x 1/2" ............................. 191542

32 ....Screw , Flat head #8-3 2 x 3/ 4" ......................... 191542-1

33 ....Switch, Low Pressure .................................... 191149-1

34 .... S hutter, B lower ................................................. 192593

35 ....Shutter Flange .................................................. 192592

36 ....Tee, 1/8" ............................................................. 40119

37 ....Tee, Pressure ................................................... 191633

38 ....Tubing, Pressure .............................................. 191562

40 ....U-Bolt Assembly (Gas Train) ......................... 191938-3

41 ....Valve, Main Gas ............................................... 78481-3

42 ....Valve, Firing....................................................... 3423-3

43 ....Valve, Solenoid Gas ......................................... 192189

44 ....Washer, Plain ................................................. 76820-18

42 ....Manual, Shut-off Valve ...................................... 211695

DETAIL BACK VIEW

LEGEND ORIFICE TABLE

Natural Size Elevation

Gas (inches) (Feet)

192222 0.555 0-2000
192222-1 0.537 2001-3000
192222-2 0.533 3001-4000

7

LB/LW PROPANE GAS TRAIN ASSEMBLY - MODEL 500

Item Description Model 500

1 .....Valve, Main Gas .............................................. 191956-1

2 .....Regulator, LP ..................................................... - - - - -

3 .....Valve, Manual Shut-Off ..................................... 3423-4

4 .....Pipe Plug ............................................................ 3348

5 .....Switch, Low Gas Pressure ............................. 191149-3

6 .....Nipple, 1" ........................................................... 86397

7 .....Nipple, 1" ......................................................... 85397-6

8 .....Nipple, 1" ............................................................ 1177

9 .....Elbow, Union, 1" ...................................................... 2482-1

Item Description Model 500

10 ....Elbow, 90° Street, 1" ............................................... 190763

11 ....Elbow, 90°, 1"..........................................................1630

12 ....Nipple, 1" ................................................................ 1179

13 ....Nipple, 1" ............................................................ 86397-11

14 ....Nipple, 1/8" ......................................................... 191147-1

15 ....Tee, 1/8" .................................................................40119

16 ....Nipple, Close Stainless .......................................191772

17 ....Orifice, Union .............................. See Orifice Table Below

LB/LW 500 ORIFICE TABLE

Propane Gas Size (In.) Elevation (Ft.)

192741 0.229 0 - 2000
192741-1 0.226 2001 - 3000
192741-2 0.223 3001 - 4000

On LB models the circulating pump must be between

the boiler inlet and the bypass (see figure below).

LW models have pump mounted inside the jacket.

Please update these numbers

LB/LW BY-PASS PARTS LIST - MODEL 500

Item Description Model 500

1 .....Ball Valve .............................................................. 191935

2 ..... Hex Reducing Bushing LW Models

..... (for use w/Relief Valve)........................................91940-1

3 .....Relief valve:

..... LB Model ............................................................210451

..... LW Model .......................................................... 98883-3

4 .....Tee, 2" x 2" x 1" ....................................................78685-2

5 .....Tee, 2" ...................................................................191584

6 .....Tee, 2" x 2" x 2" ....................................................78685-4

7 .....Valve, Drain ............................................................26273

*8 .....Valve, Manual Shutoff ............................................ - - - - -

*9 ..... Orifice, Gas Assembly (See Orifice Table)

*10 .....Tube, Condensate ............................................191746-120

*1 1 .....Strap, Cable.........................................................99592-2

*Item Not Illustrated.

8

LB/LW PROPANE GAS TRAIN ASSEMBLY - MODEL 750

Item Description Model 750

1 .......Valve, Main Gas .............................................77780

2 .......Regulator, LP ................................................ 192460

3 .......Valve, Manual Shut-Off ................................. 3423-3

4 .......Pipe Plug ........................................................ 3348

5 .......Switch, Low Gas Pressure ......................... 191149-3

6 .......Nipple, 1-1/4" ............................................... 86505-8

7 .......Nipple, 1-1/4 ................................................ 86505-2

8 .......Nipple, 1-1/4" .............................................. 86505-10

9 .......Elbow, Union ,1-1/4" ......................................... 86506

10 .......Elbow,

11 .......Elbow, 90°, 1-1/4" ......................................... 192216

90° Street , 1-1/4" ..................................94516

Item Description Model 750

12 .......Nipple, 1-1/4" ............................................... 86505-3

13 .......Nipple, 1-1/4" .............................................. 86397-11

14 .......Nipple, 1-1/4" ............................................... 86505-4

15 .......Tee, 1/8" ........................................................192465

16 .......Connector, Angle 1/8".....................................1578

17 .......Bleeder, Tube ............................................... 210016

18 .......Bleeder, Tube ............................................... 192461

19 .......Bushing, 1" x 1-1/4" .......................................99376

20 .......Nipple, Close Stainless ...............................191772

21 .......Orifice, Union .............................. See Orifice Table Below

LB/LW 750 ORIFICE TABLE

Propane Gas Size (In.) Elevation (Ft.)

192741-3 0.286 0 - 2000
192741-5 0.282 2001 - 3000
192741-7 0.278 3001 - 4000

On LB models the circulating pump must be between

the boiler inlet and the bypass (see figure below).

LW models have pump mounted inside the jacket.

Please update these numbers

LB/LW BY-PASS PARTS LIST - MODEL 750

Item Description Model 750

1 .....Ball Valve ..............................................................191935

2 ..... Hex Reducing Bushing LW Models

.....(for use w/Relief Valve)........................................ 91940-1

3 .....Relief valve:

..... LB Model .......................................................... 210451-1

..... LW Model .......................................................... 98883-3

4 .....Tee, 2" x 2" x 1" ....................................................78685-2

5 .....Tee, 2" ...................................................................191584

6 .....Tee, 2" x 2" x 2" ....................................................78685-4

7 .....Valve, Drain ............................................................26273

*8 .....Valve, Manual Shutoff ........................................... 3423-3

*9 ..... Orifice, Gas Assembly (See Orifice Table)

*10.....Tube, Condensate ............................................191746-120

*1 1 .....Strap, Cable ......................................................... 99592-2

*Item Not Illustrated.

9

LB/LW PROPANE GAS TRAIN ASSEMBLY - MODEL 1000

Item Description Part No.

Item Description Part No.

1......Valve, Main Gas, LP 300 Series .................. 77780

2...... Regulator, LP 301 Series ...........................192460

3......Valve, Firing................................................. 3423-3

4 ...... Pipe Plug ....................................................... 3348

5 ...... Switch, Low Gas Pressure....................... 191149-3

6 ...... Nipple, 1-1/4” ............................................ 86505-13

7 ...... Nipple, 1-1/4” ............................................. 86505-2

8 ...... Nipple, 1-1/4” ........................................... 86505-17

9...... Elbow, Union 1-1/4” ..................................... 86506

10 ......Elbow, 90 Street 1-1/4” ................................. 94516

11......Elbow, 90 1-1/4” ......................................... 192216

12 ......Nipple, 1-1/4” w/Tapping .......................... 86505-32

13 ...... Nipple, 1-1/4” ............................................. 86505-6

14 ...... Nipple, 1-1/4” ............................................ 86505-4

15 ......Tee, 1/8” NPT Branch.................................. 192465

16 ......Connector, Angle 1/8” ................................... 1578

17 ......Bleeder, Tube.............................................. 210016

18 ......Bleeder, Tube.............................................. 192461

19 ......Nipple, Close Stainless ........................... 191772-1

20 ...... Orifice, Union ....................... See Orifice Table Below

LB/LW 1000 ORIFICE TABLE

Propane Gas Size (In.) Elevation (Ft.)

192739 0.333 0 - 2000
192739-1 0.329 2001 - 3000
192739-2 0.325 3001 - 4000

On LB models the circulating pump must be between

the boiler inlet and the bypass (see figure below).

LW models have pump mounted inside the jacket.

Please update these numbers

LB/LW BY-PASS PARTS LIST - MODEL 1000

Item Description Part No.

1 ........Ball Valve........................................................................ 191935

*2 ........ Tank/Pump Kit (LW Models) .......................................... 210625

3 ........Hex Reducing Bushing (LB Model) .............................. 91940-8

4 ........Flush Bushing (LB Model) ........................................... 192163-2

5 ........Relief Valve (LW Model) ................................................ 98883-3

........Relief Valve (LB Model) ................................................ 210451-2

6 ........Strap, Cable (not shown) .............................................. 99592-2

7 ........Tee, Condensate ......................................................... 192040-1

8 ........Tee (For use w/relief valve):

...............LW Model ............................................................... 78685-4

...............LB Model.................................................................191584

9 ........Tee 2"x2"x2"....................................................................191584

10 ........ Tee 2"x2"x3/4"................................................................ 78685-4

11........Valve, Drain ..................................................................... 26273

12 ........ V alve, Manual Shutoff..................................................... 3423-3

13 ........ Vent Patch Assembly .....................................................192161

14 ........ Nipple (For use w/relief valve)

...............LW Model .............................................................. 20373-12

...............LB Model................................................................ 92706-4

15 ........Clamp, Hose ................................................................191794-1

*Item Not Illustrated.

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LB/LW CONTROL BOARD WHC 1502

Part Number 210128

WHC1502

LB/LW WIRING CHART

COLOR GAUGE PART NUMBER ***

White 14 41974

Black 14 99650

Green 14 41972

White 16 86580

Black 16 86578

Green 16 69058

White 18 170595

Black 18 170596

Green 18 170606

Blue 18 191719

Red 18 170603

Yellow 18 170604

Brown 18 170890

White/Red 18 191700

White/Yellow 18 191702

White/Black 18 191699
Black/White 18 191694
Yellow/Blue 18 191708

Red/Green 18 191717

***Use dash number to indicate length of wire.
Example: 20 inch long red wire would be expressed as 170603-20.

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LB/LW WIRING AND HARNESS ASSEMBLY

78468 99593-6 78469 191673 42573 210091 210152 99599-2

22-16 Ga. 16-14 Ga. 22-18 Ga. #10 Stud 22-18 Ga.

Ignition

Harness Assembly

210575

Tank Probe

Harness Assembly

210604

Gas V alve Harness Assembly

210574-1 (Propane)

210574-2 (Nat. & Prop. Model 500)

Power Harness Assembly

210579-1

(-0 0n -500 Models Only)

Transformer

Harness Assembly

210578 (Model 1000)

211330 (Models 500 & 750)

Pressure Flow Switch

Harness Assembly

210576

Blower

Harness Assembly

210609 (Model 1000)

Outlet Temperature

Control/ ECO Assembly

210572

Tank Probe (LW Models)

211541-1

PSD, Alsip, IL

Inlet Temperature

Control Assembly

210571

A.O. SMITH WATER PRODUCTS CO., INC.

5621 W. 115TH STREET • ALSIP, ILLINOIS 60803

Phone: [phone] • Fax: [phone]

Website: www.hotwater.com

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