Lochinvar Crest OFN1251 User Manual

This manual must only be used by
a qualified heating installer / service
technician. Read all instructions,
including this manual along with
the Crest Installation and Operation
Manual, and the Crest Service Manual,
before installing. Perform steps in the
order given. Failure to comply could
result in severe personal injury, death,
or substantial property damage.
⚠WARNING
Save this manual for future reference.
100302418_2000555704 Rev C
Outdoor Crest Supplemental Manual
Models: OF 751 - 6001

Lochinvar Crest OFN1251 Specifications

General

Model	OFN1251
Type	Condensing Boiler
Input BTU/hr	1, 250, 000
Efficiency	95%
Fuel Type	Natural Gas
Max. Gas Pressure	14" WC
Maximum Gas Supply Pressure	14" WC
Vent Type	Direct Vent
Water Connection Size	3 inches
Electrical Requirements	120V/60Hz
Min. Gas Pressure	4 inches W.C.
Minimum Gas Supply Pressure	4 inches W.C.

Summary

Safety and Definitions

Hazard Definitions

Categorizes risks into Danger, Warning, Caution, and Notice levels.

Pre-Operation Safety and Guidelines

Installer and User Responsibilities

Covers installer/user duties, general safety, and operational precautions.

Boiler Operation and Servicing Safety

Gas Leak Emergency Procedures

Critical actions to take if a gas leak is detected.

Boiler Overview and Installation

Boiler Location Requirements

Covers installation compliance, site selection, clearances, and foundation.

Outdoor Installation Specifics

Gas Connections

Gas Supply and Piping Requirements

Inlet Gas Supply Check

Gas Valve Maintenance

Instructions and warnings for replacing the gas valve.

Startup Procedures

Final Startup Checks and Operation

Final checks, startup steps, and operating instructions.

Combustion and System Checks

Vent, gas piping, flame, and combustion analysis.

Boiler Operation Instructions