Steffes DLF40B - Manual (Page 30)

29
Troubleshooting Information
(cont'd)
TROUBLESHOOTING GUIDES
Before starting any of the troubleshooting procedures, check voltage on the load side of all the furnace circuit
breakers. Also, check for 24 VAC between each of the 3­amp low voltage fuses and room thermostat terminal
block “C” position on the charge control circuit board. These guides are based upon standard configuration of
the furnace.
For cross reference to number coded components in each procedure, Refer to the
Exploded View Parts Diagram in this manual.
Air Delivery
A. PROBLEM: SUPPLY AIR BLOWER WILL NOT RUN WITH FAN ONLY ROOM
THERMOSTAT CALL
2
NOTE
Jumper room thermostat connections
"R" and "G" terminal block positions
in the charge control circuit board (30).
Check supply air blower
relay operation (34).
(Lower relay in panel.)
Supply Air Blower
Will Not Run
Check wall thermostat
& field wiring.
Supply Air Blower Runs
Check supply air blower relay
coil voltage for 24 VAC.
Check supply air blower
limit switch (54).
Ok
Check for 24 VAC between room
thermostat connection "C" terminal
block position and the two 3­amp
low voltage fuses on the charge
control circuit board (30).
Replace supply air blower
relay (34).
Ok
No Voltage
Replace supply air
blower limit (54). Check unit wiring &
supply air blower motor (58).
Open
Ok
Replace charge control
circuit board (30).
Check unit wiring and/or
replace control
transformer (28).
Ok
No Voltage