
Page 2
31-5000736 Rev. 0
SERVICE MANUAL
NF80DS
Table of Contents
Technical Specifications - NF80DS
.............................3
Parts Arrangement
.......................................................6
Unit Components
.........................................................7
Placement & Installation
............................................17
Start-Up
.....................................................................17
Heating System Service Checks
...............................17
Typical Operating Characteristics
..............................21
Maintenance
..............................................................22
Wiring Diagram
..........................................................25
Troubleshooting: Heating Sequence of Operation
....26
Troubleshooting: Heating Sequence of Operation
(Continued)
................................................................27
Troubleshooting: Cooling Sequence of Operation
.....28
Troubleshooting: Continuous Fan / Accessories
Sequence of Operation
..............................................29
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to
the potential for personal injury or death.
Electric shock hazard.
Can cause injury or death. Before attempting
to perform any service or maintenance,
turn the electrical power to unit OFF at
disconnect switch(es). Unit may have
multiple power supplies.
WARNING
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves
and protective clothing.
CAUTION
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer (or
equivalent), service agency or the gas supplier.
WARNING