Thermal Solutions APEX APX425C User Manual

106308-05 - 3/23
Installation, Operating and Service Instructions for
APEX
TM
Commercial
 Condensing
 High Efficiency
 Direct Vent
 Gas-Fired
 Water Boiler
Models:
• APX425C
• APX525C
• APX625C
• APX725C
• APX825C
9700609
Manual Contents Page
1. Product Description, Specifications & Dimensional
Data ........................................4
2. Unpacking Boiler .............................8
3. Pre-Installation and Boiler Mounting .............8
4. Venting ....................................14
5. Condensate Disposal ........................39
6. Water Piping and Trim ........................41
7. Gas Piping .................................53
8. Electrical ...................................58
9. System Start-up .............................68
10. Operation ..................................77
11. Service and Maintenance ...................115
12. Troubleshooting ...........................121
13. Service Parts ..............................136
Appendix A: Instructions for High Altitude Installations
Above 2,000 ft. ................................150
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, injury, or
death. For assistance or additional information, consult a qualified installer, service agency or the gas supplier.
This boiler requires a special venting system. Read these instructions carefully before installing.
!

Thermal Solutions APEX APX425C Specifications

General

Brand	Thermal Solutions
Model	APEX APX425C
Category	Boiler
Language	English