Table of Contents
General Information
................................................3-5
Specifications
.........................................................6, 7
Schematic Diagrams
..............................................8, 9
Fault Isolation
..................................................... 10-12
Electrical Diagnostic Points
305e/o, 305i, 505e/o 505i ................................13, 14
705e/o (ASME), 705i (ASME) .........................15, 16
Wire Diagrams
305e/o, 305i, 505e/o, 505i .....................................17
705e/o (ASME), 705i (ASME) ...............................18
Flushing the Heat Exchanger
.................................19
Component Replacement Instructions
Gas Control Assembly
305e/o, 305i, 505e/o, 505i ...............................20, 21
705e/o (ASME), 705i (ASME) ..........................22, 23
Fan
505e/o, 305e/o.......................................................24
305i, 505i ...............................................................25
705e/o (ASME), 705i (ASME) ...............................26
PC Board
305e/o, 305i, 505e, 505i ................................. 27, 28
705e/o (ASME ), 705i (ASME) ............................. 29
Water Flow Control Assembly
305e, 305i, 505e, 505i .................................... 30, 31
505e, 505i ....................................................... 32, 33
705e/o (ASME), 705i (ASME) .............................. 34
Heat Exchanger
305e ................................................................. 35-37
505e /o.............................................................. 38-40
305i .................................................................. 41-44
505i .................................................................. 45-49
705e/o (ASME)................................................. 50-51
705i (ASME) .................................................... 52-54
Gas Pressure Setting Procedure
..................... 55, 56
Manifold Pressure Settings
.................................... 57
Dip Switches
............................................................ 58
On-Demand Gas Tankless Water Heater Service Manual
2
Key to Trade Names in this Manual:
(ASME) Indicates that the ASME models are included.
(N) Indicates Natural Gas.
(P) Indicates Propane Gas.
(e) Indicates Outdoor Models.
(i) Indicates Indoor Models.
(o) Indicates Outdoor Models.