WARNINGS 4
Pay Attention to These Terms 4
BEFORE INSTALLATION 5
Product Receipt 5
Model Identification 5
Ratings and Certifications 5
Installations at Elevation 5
Component Locations 6
General Information 7
GENERAL SAFETY 8
Time/Temperature Relationships in Scalds 8
INSTALLATION 9
Installation Codes 9
Equipment Base 9
Clearances 9
Combustion and Ventilation Air 11
Conventional Combustion
Air Supply 11
Water Piping 12
Hydronic Heating 14
Domestic Hot Water Piping 16
Gas Supply 17
Electrical Power Connections 19
Venting 21
Outdoor Installation 31
CONTROLS 32
Ignition Control Module 32
Modulating Temperature Control
(Optional) 32
High Limit (Manual Reset) 32
High Limit — Auto Reset (Optional) 32
Flow Switch 33
High and Low Gas Pressure Switches
(Optional) 33
Low Water Cut Off (Optional) 33
WIRING DIAGRAM—MODELS
HD101–HD401 34
HD TROUBLESHOOTING 35
PRE-START-UP 36
Filling System-Heating Heaters 36
Domestic Hot Water Heaters 36
Inspect Venting System 36
Pre-Start-Up Check 36
INITIAL START-UP 36
Tools Needed 36
Preparation for Start-Up 36
Start-Up 38
Main Burner Adjustment 38
Gas Valve Adjustment 38
Gas Type Conversion on Valve 39
Safety Inspection 39
Follow-Up 39
POST START-UP CHECK 40
Air Filter Inspection/Removal 40
Heat Exchanger Removal 41
MAINTENANCE 42
Suggested Minimum Maintenance
Schedule 42
APPENDIX 43
Inside Combustion Air Contamination 43
CONTENTS
3