Page 23
Leak Check
After gas piping is completed, carefully check all piping 
connections  (factory-  and  eld-installed)  for  gas  leaks. 
Use a leak detecting solution or other preferred means.
NOTE - If  emergency  shutoff  is  necessary,  shut  off  the 
main  manual  gas  valve  and  disconnect  the  main  power 
to  the  furnace.  The  installer  should  properly  label  these 
devices.
 CAUTION
Some soaps used for leak detection are corrosive to 
certain metals. Carefully rinse piping thoroughly after 
leak test has been completed. Do not use matches, 
candles, ame or other sources of ignition to check for 
gas leaks.
The furnace must be isolated by closing its individual man-
ual  shut-off  valve  and  disconnecting  from  from  the  gas 
supply system the during any pressure testing of the gas 
supply  system  at  pressures  greater  than  1/2  psig  (3.48 
kPa, 14 inches w.c.).
 IMPORTANT
When testing pressure of gas lines, gas valve must be 
disconnected  and  isolated.  See  gure  27.  Gas  valves 
can be damaged if subjected to pressures greater than 
1/2 psig (3.48 kPa, 14 inches w.c.).
MANUAL MAIN
SHUT-OFF VALVE
WILL NOT HOLD
NORMAL TEST
PRESSURE
CAP
ISOLATE
GAS VALVE
FURNACE
1/8 NPT PLUG
FIGURE 27 
Electrical 
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
 CAUTION
Electrostatic discharge can affect electronic 
components. Take precautions to neutralize 
electrostatic charge by touching your hand 
and tools to metal prior to handling the 
control.
 WARNING
Electric Shock Hazard. Can cause injury or 
death. Unit must be properly grounded in 
accordance with national and local codes.
 WARNING
Fire Hazard. Use of aluminum wire with this product may 
result in a re, causing property damage, severe injury 
or death. Use copper wire only with this product.
 CAUTION
Failure to use properly sized wiring and circuit breaker 
may result  in property damage.  Size wiring  and circuit 
breaker(s) per Product Specications bulletin (EHB) and 
unit rating plate.
The unit is equipped with a eld make-up box on the left 
hand side of the cabinet. The make-up box may be moved 
to the right side of the furnace to facilitate installation. If 
the make-up box is moved to the right side, clip the wire 
ties that bundle the wires together. The excess wire must 
be pulled into the blower compartment. Secure the excess 
wire to the existing harness to protect it from damage.
INTERIOR MAKE-UP BOX INSTALLATION
BOX
Right Side
FIGURE 28 
Refer to gure 29 for schematic wiring diagram and trou-
bleshooting and table 7 and gure 29 for eld wiring.
The power supply wiring must meet Class I restrictions. 
Protected by either a fuse or circuit breaker, select circuit 
protection and wire size according to unit nameplate.
NOTE - Unit  nameplate  states  maximum  current  draw. 
Maximum over-current protection allowed is 15 AMP.
 Holes are on both sides of the furnace cabinet to facilitate 
wiring.
Install a separate (properly sized) disconnect switch near 
the furnace so that power can be turned off for servicing. 
Before connecting the thermostat, check to make sure 
the wires will be long enough for servicing at a later date. 
Make sure that thermostat wire is long enough to facilitate 
future removal of blower for service.