Troubleshooting Chart; Modulating Integrated Furnace Control - Rheem RGFE Installation Instructions Manual

FIGURE 82

TROUBLESHOOTING CHART

MODULATING INTEGRATED
FURNACE CONTROL (IFC)
TROUBLESHOOTING GUIDE
1) Set DIP switches SW2-2 to "OFF" and SW2-3 to
"ON" for test mode - high fire.
2) Set FAN switch to "AUTO" on T-stat.
3) Set thermostat to call for heat (set temp.
differential to greater than 10°F).
4) "H" should be displayed at "SSD's" and should
Be on steady, if flashing check dip switches
(Item "1").
For Comm. System
For Non-Comm. Systems.
"A capital is displayed at IFC SSD'S"
Lower case "h"
Is a modulating
T-stat connected?
2 Stg. or 1 Stg. Non Comm. T-stat
(pre-purge) IDM runs for 30 sec. at high speed?
Spark Electrodes (SE) Energize?
Does ECM blower start on high heat
speed 15-20 seconds after burners light?
Remove heat call by setting T-stat set point below
room temperature. remove power to furnace and open
blower door. Set dip switch SW2-2 to "ON" and SW2-3
to "OFF". Replace furnace door, reset power to
furnace. Initiate new heat call. Allow heat call to
proceed through blower on delay. The burners drop
from high fire to low (40%) rate and I.B.M. energizes at
low heat CFM.
After Blower on delay, Does IDM switch to low speed
and remain at low speed after switching?
Does I. B. M. energize at low speed?
Does furnace continue to operate at low
Dual SSD'S "ON"
Is thermostat heat call present?
For 24 VAC (Non-Comm. T-stat., is 24 VAC on W1 and/or W2 of
IFC. H or h should be displayed at SSD'S.
Is a fault code displayed at IFC?
(After 10 Sec. a fault code will display anyway)
H or h only
For 1st 10 Sec. only
-Check line voltage at I.D.M.
-Check Wires And connections between I.D.M. and I.F.C.
-Ensure line voltage between J2, Pin 1 & J2, Pin 4 of I.F.C. (High IN Output).
-Check I.D.M. Capacitor.
Check t-stat, replace if
necessary.
Check "V" signal wires &
connections, replace or
repair as necessary
Does IDM Run for 60 Sec. and then off
for five minutes with fault
45, 48 or 57 displayed?
PROBLEM
PERSISTS
G0 T0 Does gas valve remain
I
- Check all connections between I.F.C. & E.C.M. Motor.
- Check 24v to E.C.M. control (4pin connector, pin 1-4)
- Check Dip switch setting.
- Check P.F.C. choke.
- Check all wiring and connections to P.F.C choke.
- Check fault code display, see "fault codes" in I & O.
- Check line voltage to motor (115VAC).
Note: IFC SSD's will display "22, 33 or 23".
- ensure no restrictions, such as dirty filter, blower wheel,
dampers or closed registers, Etc. exist.
- ensure good wire and connections between I.F.C. and all limits.
makes sure limits are not open when circulating air temperature is within a
specific range.
- Ensure rollouts or overtemperature limits do not need to be
reset. make sure no flame rollout in burner compartment due to blocked flue
or heat exchanger or combustion restriction.
- ensure furnace is not overfired (temp rise is above stated
range). Check gas valve, proper orifice size, gas presure
Check to make sure test mode dip switches are properly set.
Ensure T-stat not
switching to high fire or
FAULT
Under "Troubleshooting"
in I & O Manual
- See FAULT CODES under "Troubleshooting" in
I&O Manual.
See I&O.
energized?
main power to unit, wait 30 seconds then reset power or removed heat
call and re-establish.
?
If good flame is not sensed a fault code
"11" or "13" will be displayed at SSD's
"12" is low flame sense, furnace should
still operate well.
-Grounding on I.F.C. in place and continuity between screw and field
-installed ground.
-Flame sense rod clean (clean if nessessary).
-Wire continunity between flame sense rod and J1, Pin1 on I.F.C.
-Flame carries across all burners, and all burners stay lit.
- Fault codes at IFC SSD - see FAULT CODES under troubleshooting
in I&O manual.
- 24V Between IFC pins J16, Pin 4 & J16, Pin 5 of I.F.C.
- Make sure heat call present at T-stat.
- T-stat wires and connections
- Check wire and all connections between I.F.C.J2 and I.D.M
- Check for 115 VAC on P2.
- Check I.D.M. capacitor.
- Check I.D.M. low speed. Replace if neccessary.
- Check all connections between IFC and ECM motor.
- Check 24V to ECM Motor. (low voltage connector, pins 1 & 4)
- Check P.F.C. Choke.
- Check all wiring and connections to P.F.C. choke.
ECM = Constant CFM Blowers. (Electronically commutated motor)
TSTAT = Thermostat.
IDM = Induced Draft Motor (or Inducer).
IFC = Integrated Furnace Control (or control board).
PS = Pressure Switch(es).
PFC = Power Factor Correction Choke.
SE = Spark Electrode (s).
SSD = Seven Segment Display of Furnace control
COMM. = Communication.
I&O = Installation & Operation Instructions Manual.
J16-4 J16-5 on IFC.
If IFC goes into lockout ("r" will be displayed at SSD's), shut off
Fault code
"45", "46" or
"57" displayed
at SSD's.
- Check test mode dip switches.
- Make sure test mode has not
expired (1 hour limit).
C
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