| | Sheet Metal Components | | |
| 1 | 20F3320 | Panel, Jacket, Front | | |
| 2A | 5F3420 | Panel, Jacket, Side, Lower Left | | |
| 2B | 5F3421 | Panel, Jacket, Side, Lower Right | | |
| 3A | 5F3520 | Panel, Jacket, Side, Lower Left | | |
| 3B | 5F3521 | Panel, Jacket, Side, Lower Right | | |
| 4 | 5F3400 | Panel, Side, Top Left, Jacket | | |
| 5 | 5F3500 | Panel, Side, Top Right, Jacket | | |
| 6 | 20F3220 | Panel, Rear, Jacket | | |
| 7 | 20F3021 | Panel, Rear, Jacket | | |
| 8 | 20F3100 | Weldment, Vent Plate | | |
| 9 | 20F3800 | Weldment, Housing, Air Inlet/Filter | | |
| 10 | 12F3701 | Panel, Access, Filter | | |
| 11 | A2088700 | Filter, Combustion Air | | |
| 12 | 5F3015 | Panel, Enclosure, Pump | | |
| 13 | 5F3016 | Cover, Housing, Pump | | |
| 14 | 20F3304 | Cover, Pipe, Gas Manifold | | |
| | Internal Components | | |
| 16 | 20F1020 | Assembly, Base | | |
| 17 | 20F2003 | Panel, Front, Combustion Chamber | | |
| 18 | 20F2006 | Panel, Rear, Combustion Chamber | | |
| 19 | 20F2001 | Panel, Top, Combustion Chamber | | |
| 20 | 5C2602 | Weldment, Chamber, Left Side, Bottom | | |
| 21 | 5C2202 | Weldment, Chamber, Right Side. Bottom | | |
| 22 | 5C2002 | Panel, Chamber, Left/Right Side, Top | | |
| 23 | 10956000 | Assembly, Sight Glass | | |
| 24 | 5F2015 | Panel, Left Side, Air Box | | |
| 25 | 5F2016 | Panel, Right Side, Air Box | | |
| 26 | 20F2004 | Panel, Right Side, Air Box | | |
| 27 | 5F2005 | Cover, Access Panel, Air Box | | |
| 30 | 20F2002 | Divider, Front Chamber, Combustion Chamber | | |
| 31 | 12F2027 | Assembly, Exhaust Stack | | |
| 32 | 20C4000 | Assembly, Copper Tube, Heat Exchanger | | |
| 20C4020 | Assembly, Cupro-Nickel, Heat Exchanger | | |
| 33 | T2015600 | Tile, Side (Left and Right) | | |
| 35 | T2016800 | Tile, Front, Left Side | | |
| 36 | T2017100 | Tile, Front, Right Side | | |
| 37 | T2016900 | Tile, Front, Center | | |
| 39 | T2016600 | Tile, Rear, Left Side | | |
| 40 | T2016600 | Tile, Rear, Right Side | | |
| 41 | T2017200 | Tile, Rear, Center | | |
| 43 | T2017400 | Tile, Bottom, Left Side | | |
| 44 | T2017400 | Tile, Bottom, Right Side | | |
| 45 | T2015900 | Tile, Bottom, Center | | |
| 46 | A2111900 | Blower | | |
| 47 | 5C5300 | Weldment, Blower Mount | | |
| 47A | 15C5400 | Assembly, Blower Damper | | |
| 48 | 20C6100 | Manifold, Gas Supply | | |
| 49 | V2003300 | Valve, Ball, Manual Shutoff | | |
| 50 | V2016000 | Valve, Gas, Combination | | |
| 51A | P2073600 | Weldment, Pipe, Gas Valve/Ball Valve | | |
| 51B | P0014700 | 4" Nipple, black | | |
| 51C | P0030400 | Union | | |
| 52 | V2000200 | Valve, Ball, Manual Shutoff, Secondary | | |
| 53 | L2012600 | Manifold, 4 Burner/Orifice, Left | | |
| L2012700 | Manifold, 4 Burner/Orifice, Right | | |
| 54 | L2012200 | Assembly, 3 Burner | | |
| L2012500 | Assembly, 4 Burner | | |
| 55 | L2013000 | Orifice, Gas, Natural | | |
| L2012400 | Orifice, Gas, Propane | | |
| 57 | 2400-286 | Ignitor, Hot Surface with Gasket | | |
| | Heat Exchanger Components | | |
| 58 | E0013000 | Flow Switch | | |
| 59 | E2076500 | Low Water Cutoff (optional) | | |
| 60 | A0079000 | Gauge, Temperature/Pressure | | |
| 62 | 20130002 | Tee, Adapter, Outlet, Cast Iron | | |
| 20130009 | Tee, Adapter, Outlet, Cast Iron (boiler) | | |
| 20150303 | Tee, Adapter, Outlet, Bronze | | |
| 63 | A0002700 | Relief Valve, Hydronic, 75 Psi | | |
| A0064400 | Relief Valve, Water Heater, 125 Psi | | |
| 64 | 10391303 | Flange, Connection, Cast Iron | | |
| 10391304 | Flange, Connection, Bronze | | |
| 65 | S0063700 | Gasket, Connection Flange | | |
| 66 | 10364504 | Cover, In/Out, Glass-Lined Cast Iron | | |
| 10364501 | Cover, In/Out, Bronze | | |
| 67 | S0095100 | Gasket, Header/Cover | | |
| 68 | 20230101 | Water Barrier, Inlet/Outlet | | |
| 69 | 10338300 | Baffle, Water Deflector, Inlet | | |
| 70 | E2058300 | Well, Immersion, Temperature Control | | |
| 71 | 10364300 | Cover, Return, Glass-Lined Cast Iron | | |
| 10364301 | Cover, Return, Bronze | | |
| 72 | S2056900 | Pump Housing, Glass-Lined Cast Iron | | |
| 73 | 10338400 | Baffle, Diffuser, Pump Housing Inlet | | |
| | Electrical Components | | |
| 74 | E2313900 | Control, Gas Ignition, Three-Try (standard) | | |
| E2107300 | Control, Gas Ignition, Single-Try (CSD-1 option) | | |
| 75 | E0109200 | SPDT, Toggle Switch | | |
| 75A | E2056300 | DPDT Switch | | |
| 76 | E2327500 | Terminal Block, 16-Position, Dual Row | | |
| 77 | E0015900 | Switch, Hi-Limit Manual Reset (boiler) | | |
| E2217800 | | | |
| 78 | E0093200 | | | |
| 79 | 5F7001 | Panel, Mounting, Limits/Ignition Control | | |
| 80 | 5F7003 | Panel, Cover, High Limit/Ignition Control | | |
| 81 | 5F7006 | Panel, Access, Terminal | | |
| 82 | E2337700 | | | |
| 83 | E2327700 | Terminal Block, 6-Position, Dual Row | | |
| 84 | E2327600 | Terminal Block, 12-Position, Dual Row | | |
| 85 | E0240900 | Switch, Pressure, Diaphragm, SPDT | | |
| 86 | 5F7007 | Bracket, Pressure Switch | | |
| 87 | E2312800 | Transformer, 150 VA, 120/24V | | |
| 88 | E2077700 | Relay, Time Delay (24 VAC) Delay on Break, Adj. | | |
| 89 | E2327800 | Relay, 24VAC, DPDT | | |
| 90 | 5F7005 | Panel, Mounting, LWCO Switch (optional) | | |
| 91 | E2328400 | Wire Harness #1, Fenwal | | |
| 92 | E2330100 | Wire Harness #2, Control Panel | | |
| 93 | E2328600 | Wire Harness #3, Main | | |
| 94 | E2328700 | Wire Harness #4, Local Remote SW | | |
