507270-03 Page 59 of 60Issue 1917
Planned Service
A  service  technician  should  check  the  following  items 
during  an  annual  inspection.  Power  to  the  unit  must  be 
shut off for safety.
Fresh air grilles and louvers  (on  the  unit  and  in  the 
room where the furnace is installed) - Must be open and 
unobstructed to provide combustion air.
Burners - Must be inspected for rust, dirt, or signs of water.
Vent pipe - Must be inspected for signs of water, cracked, 
damaged or sagging pipe, or disconnected joints.
Unit appearance - Must be inspected for rust, dirt, signs of 
water, burnt or damaged wires, or components.
Blower access door  -  Must  be  properly  in  place  and 
provide a seal between the return air and the room where 
the furnace is installed.
Return air duct - Must be properly attached and provide 
an air seal to the unit. 
Operating performance - Unit must be observed during 
operation  to  monitor  proper  performance  of  the  unit  and 
the vent system. 
Combustion gases  -  Flue  products  should  be  analyzed 
and compared to the unit specications.
Problems  detected  during  the  inspection  may  make  it 
necessary to temporarily shut  down  the  furnace until the 
items can be repaired or replaced. 
Instruct the homeowners to pay attention to their 
furnace.  Situations  can  arise  between  annual  furnace 
inspections  that  may  result  in  unsafe  operation.  For 
instance, items innocently stored next to the furnace may 
obstruct  the  combustion  air  supply.  This  could  cause 
incomplete  combustion  and  the  production  of  carbon 
monoxide gas.
Table 14. Diagnostic Codes
LED Status Fault Description
LED Off
No power to control or control hardware 
fault detected
LED On Normal operation
1 Flash Flame present with gas valve off
2 Flashes Pressure switch closed with inducer off
3 Flashes Pressure switch open with inducer on
4 Flashes High limit switch open
5 Flashes Rollout switch open
6 Flashes Pressure switch cycle lockout
7 Flashes Lockout due to no ignition
8 Flashes Lockout due to too many ame dropouts
9 Flashes Incorrect line voltage phasing
Repair Parts List
The following repair parts are available through Allied Air dealers. When ordering parts, include the complete furnace model 
number listed on the CSA nameplate. All service must be performed by a licensed professional installer (or equivalent), 
service agency, or gas supplier.
Cabinet Parts
•  Upper Access Panel
•  Blower Access Panel
•  Top Cap
Control Panel Parts
•  Transformer
•  Integrated Control Board
•  Door Interlock Switch
Blower Parts
•  Blower Wheel
•  Motor
•  Motor Mounting Frame
•  Motor Capacitor
•  Blower Housing Cutoff Plate
Heating Parts
•  Flame Sensor
•  Heat Exchanger Assembly
•  Gas Manifold
•  Combustion Air Inducer
•  Gas Valve
•  Main Burner Cluster
•  Main Burner Orices
•  Pressure Switch
•  Ignitor
•  Primary Limit Control
•  Flame Rollout Switches