506843-01
Page 1 of 39
Issue 1132
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.
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
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 installer (or equivalent), service
agency or the gas supplier.
WARNING
This manual must be left with the homeowner for future reference.
INSTALLATION INSTRUCTIONS
GDD80C
Warm Air Gas Furnace
Downflow Air Discharge
(P) 506843-01
*P506843-01*
Unit Dimensions .............................................................. 2
GDD80C
Parts Arrangement
.................
........................
.......
3
GDD80C
Gas Furnace
....
........................
.............................
4
Shipping and Packing List ............................................... 4
Safety Information .......................................................... 4
Use of Furnace as a Construction Heater ....................... 5
General .......................................................................... 6
Combustion, Dilution, Ventilation Air ................................. 6
Setting Equipment ........................................................... 9
Filters ........................................................................... 12
Duct System ................................................................. 12
Venting ......................................................................... 12
Gas Piping .................................................................... 21
TABLE OF CONTENTS
Electrical ..................................................................... 22
Unit Start-Up ............................................................... 27
Heating Sequence of Operation ................................. 28
Gas Pressure Adjustment ........................................... 28
Control Settings .......................................................... 28
High Altitude ................................................................ 29
Other Unit Adjustments .............................................. 29
Blower Performance .................................................... 31
Service ........................................................................ 32
Planned Service ........................................................... 35
Control Diagnostic Codes .............................................. 35
Repair Parts List ........................................................... 36
Start-Up Check List ....................................................... 37
Manufactured By
Comfort-Aire / Century
1900 Wellworth Ave.
Jackson, MI 49203
