3
CONTENTS
1. WARNINGS ................................................................... 4
1.1. Pay Attention to These Terms ..............................4
2. WATER CHEMISTRY ................................................... 5
2.1. Automatic Chlorinators and Chemical
Feeders .......................................................................5
3. OPERATING INSTRUCTIONS .................................... 6
3.1. Start-Up Procedures ...............................................6
3.2. Before Start-Up .........................................................6
3.3. Visual inspection ......................................................6
3.4. Caution ........................................................................6
3.5. Maintenance .............................................................8
3.6. Cold Weather Operation ........................................8
4. BEFORE INSTALLATION ............................................ 9
4.1. Receiving equipment ..............................................9
4.2. Rating and certifications .......................................9
4.3. Ambient Temperature Rating of Heater
Components ..............................................................9
4.4. Atmospheric heaters ..............................................9
5. INSTALLATION ............................................................. 9
5.1. Installation Codes ....................................................9
5.2. Clearances .............................................................. 10
5.3. Outdoor Heater Installation ............................... 11
5.4. Combustion and Ventilation Air ....................... 12
5.5. Vent Piping .............................................................. 15
5.6. Gas Supply Connections .................................... 16
5.7. Water Connection Installation .......................... 18
5.8. Unitherm Governor Operation .......................... 18
5.9. Internal Automatic Bypass Valve ..................... 18
5.10. External Auxiliary Bypass Valve ........................ 19
5.11. Auxiliary Bypass Valve Adjustment ................. 19
5.12. Pressure Relief Valve Installation .................... 19
5.13. Plumbing.................................................................. 19
6. ELECTRICAL WIRING ...............................................20
6.1. Electrical Power Draw ......................................... 20
6.2. Transformer Wiring .............................................. 21
7. WIRING DIAGRAM ....................................................23
8. CONTROLS..................................................................24
8.1. Control Panel Removal ........................................ 24
8.2. Control Adjustments ............................................ 24
8.3. Operation ................................................................. 24
8.4. Status and Diagnostics ....................................... 26
8.5. Remote Control Wiring ........................................ 28
9. REPLACEMENT PARTS ............................................32
10. TROUBLESHOOTING ...............................................33
10.1. Mechanical ............................................................. 33
10.2. Control Logic - Flow Chart ................................. 34
11. ILLUSTRATED PARTS LIST......................................35
