Technical information

1. These furnaces are manufactured for natural gas operation. Optional kits are available for conversion to propane
operation.
2. For elevations above 2000 feet the rating should be reduced by 4% for each 1000 feet above sea level. The furnace
must not be derated, orifice changes should only be made if necessary for altitude.
3. The total heat loss from the structure as expressed in TOTAL BTU/HR must be calculated by the manufacturers
method or in accordance with the "A.S.H.R.A.E. GUIDE" or "MANUAL J-LOAD CALCULATIONS" published by the
AIR CONDITIONING CONTRACTORS OF AMERICA. The total heat loss calculated should be equal to or less than
the heating capacity. Output based on D.O.E. test procedures, steady state efficiency times output.
4. Minimum Circuit Ampacity calculated as: (1.25 x Circulator Blower Amps) + I.D. Blower Amps.
FURNACE SPECIFICATIONS
12
Model
GUCA045BX30 GUCA070BX30 GUCA070BX40 GUCA090BX40 GUCA090BX50 GUCA115BX50
Btuh
Input (US) 46,000 69,000 69,000 92,000 92,000 115,000
Output (US) 42,800 64,400 63,900 86,000 85,300 106,500
Input (CAN) 46,000 69,000 69,000 92,000 90,000 115,000
Output (CAN) 42,800 64,400 64,400 86,000 85,300 106,500
A.F.U.E. 92.1% 92.1% 92.1% 92.1% 92.1% 92.1%
Rated External Static (" w.c.) .20 - .50 .20 - .50 .20 - .50 .20 - .50 .20 - .50 .20 - .50
Temperature Rise (°F) 35 - 65 35 - 65 35 - 65 35 - 65 35 - 65 35 - 65
ID Blower Pressure Switch Trip Point (" w.c.) -0.37 -0.37 -0.37 -0.37 -0.37 -0.37
Front Cover Pressure Switch Trip Point (" w.c.) -0.37 -0.37 -0.37 -0.37 -0.37 -0.37
Blower Wheel (D" x W") 11 x 6 11 x 7 11 x 9 11 x 9 11 x 9 11 x 10
Blower Horsepower 1/3 1/2 1/2 1/2 3/4 1/2
Blower Speeds 4 4 4 4 4 4
Max CFM @ 0.5 E.S.P. 1196 1407 1643 1544 2017 1976
Power Supply 115-60-1 115-60-1 115-60-1 115-60-1 115-60-1 115-60-1
Minimum Circuit Ampacity (MCA) 9.0 9.8 8.9 8.9 12.2 10.9
Maximum Overcurrent Device 15.0 15.0 15.0 15.0 15.0 15.0
Transformer (VA) 40 40 40 40 40 40
Heat Anticipator (Amps) 0.7 0.7 0.7 0.7 0.7 0.7
Primary Limit Setting (°F) 150 150 160 150 150 150
Auxiliary Limit Setting (°F) 150 150 150 150 150 160
Rollout Limit Setting (°F) 200 200 210 200 220 220
Fan Delay On Heating 30 secs. 30 secs. 30 secs. 30 secs. 30 secs. 30 secs.
Off Heating * 90 secs. 90 secs. 90 secs. 90 secs. 90 secs. 90 secs.
Fan Delay On Cooling 5 sec. 5 sec. 5 sec. 5 sec. 5 sec. 5 sec.
Off Cooling 45 secs. 45 secs. 45 secs. 45 secs. 45 secs. 45 secs.
Gas Supply Pressure (Natural/Propane) ("w.c.) 7 / 11 7 / 11 7 / 11 7 / 11 7 / 11 7 / 11
Manifold Pressure (Natural/Propane) ("w.c.) 3.5 / 10 3.5 / 10 3.5 / 10 3.5 / 10 3.5 / 10 3.5 / 10
Orifice Size (Natural/Propane) #43 / #55 #43 / #55 #43 / #55 #43 / #55 #43 / #55 #43 / #55
Number of Burners 233445
Vent Connector Diameter (inches) 2 2 2 2 2 2
Combustion Air Connector Diameter (inches) 2 2 2 2 2 2
Shipping Weight (lbs.) 131 144 152 166 175 187
* Off Heating - This fan delay timing is adjustable (60, 90, 120 or 180 seconds), 90 seconds as shipped.