Troubleshooting; Troubleshooting Guide - Rheem 96P series Installation Instructions Manual

FIGURE 51
INTEGRATED FURNACE CONTROL TROUBLESHOOTING GUIDE
NOTE: Always verify gas valve inlet and outlet gas pressure.
1) Set FAN switch to "AUTO "
2) Set thermostat to call for heat (set temp. differ-
ential to greater than 10 F
PREPURGE
Does the IDM Energize?
IDM Runs for 30 sec. pre-purge ?
IGNITION TRIAL
IBM "ON" DELAY
Does Main Burner Light and stay lit?
Does IBM start on heat speed 20 seconds
STEADY HIGH HEAT
setpoint & room temp. (check t-stat specs)
Do IDM, IBM & Gas Valve Drop to Low Stage?
STEADY LOW HEAT
Does main burner remain lit until
Does thermostat maintain reasonable room
temperature near setpoint ?
END HEAT CALL
Set thermostat to off position (W to C = ØV)
POST-PURGE
Does gas valve shut off immediately?
Does IDM shut off after ten second post-purge?
IBM "OFF" DELAY
Does IBM shut off after a max. of 3 min?
STEADY OFF
Heat-mode troubleshootin g
108
START
"FAULT DISPLAYED ?"
NO
24V on W to IFC?
YES
NO
YES
- Check line voltage at IDM.
- Check wires and connections between IDM and IFC.
- Ensure line voltage on IDM pins of IFC connector .
- Check IDM capacitor (90+ only) .
CHECK BLINK CODES
- Check for open limit or limit cir cuit.
Does IDM Run for 60 sec. and then off for Five minutes
NO
YES
FOR DIRECT SPARK IGNITION
- Check ignitor connected .
- Check ignitor wires.
Spark Ignitor Sparking?
- Check ignitor for fractures or cracking
NO
- Check ignitor placement .
YES
- If problem persists, check IFC*.
**
Is the gas valve energized?
NO
YES
NO
after burners light ? - Check line voltage between "HEAT" and "NEUTRAL" on IFC.
NO
- Check wires, connections, and continuity between IFC and IBM.
YES
- Check IBM capacitor .
- Check IBM.
YES
NO
YES
Is Limit cir cuit open or opening and closing?
Note: IFC Status LED should be blinking a Fault Code.
YES
NO
CHECK:
heat call ends?
BLOCKED DRAIN - (fault "59" should be present)
YES
AIRFLOW - ensure no restrictions, such as dirty filte r, dampers, closed registers, etc.
LIMITS - ensure good wire and connections between IFC and all limits. Make sur e
limits are not open when cir culating air temperature is within a specified range.
D
ROLLOUTS - ensure rollouts or overtemperature limits do not need to be reset. Make
sure no flame rollout in burner compartment due to blocked flu or heat exchanger .
OVERFIRE - ensure furnace is not overtemperature (temp rise is above stated range) .
Check gas valve, proper orifice size, gas pressure, etc.
Ensure thermostat is properly placed and not improperly affected by
NO
registers, fans, sunlight, heat through walls, pipes, or wires in walls .
YES
NO
Double check - Is W off at IFC?
NO
(W to C = ØV?)
YES
Ensure TSTAT is not in "FAN" position.
Is disply flashing a fault code
Is "FLAME" LED blinking or steady-on ?
NO
YES
NO
YES
END
REPEAT THIS PROCEDURE UNTIL TROUBLE-FREE OPERATION IS OBTAINED.
FLAME (AMBER) LED CODES
KEY TO ABBREVIATIONS
OFF = No Flame Presen t
IBM = Indoor Blower Motor
RAPID BLINK = Unexpected Flame
IDM = Induced Draft Motor
SLOW BLINK = Marginal Flame Sense
IFC = Integrated Furnace Control
STEADY ON = Normal Flame Sense
PS = Pressure Switch(es)
SE = Spark Electrode
DSI = Direct-Spark Ignition
YES "ATTEND TO FAULT"
- Check thermostat in "heat" mode,
NO
batte ry, wire, and connections.
- Check PS contact s
- Check wires for short.
- Check IFC*.
- Check switches and hoses for
water or moistur e
Check IFC*.
NO
Does IDM run
YES
indefinately .
NO
YES
GO TO
YES I
If " I " did not
resolve issue.
Check for high gas valve relay
Check
on IFC stuck closed. Replace
T- STAT
IFC, if neccessary
YES
YES
24 VAC on
NO High Gas Valve
W2?
Energized?
NO
Low Pressure
CHECK: NO YES
-IBM Switch Open?
-IBM Capacitor
-Wiring
-Flame Sense Rod
Is the IFC sensing a good flame: NOTE:
NO
Flame sense light should be steady-on
when burners are lit. If flame LED blinking,
or off, flame sense is low or absent.
PROBLEM
STILL
PRESENT
- Check IFC*.
YES
Voltage present at gas valve?
YES NO
Fault Code Present
SEE FAULT CODES
"FLAME" LED BLINKING
OR STEADY ON
GO TO
E
If "E" did not
resolve issue
Check IFC*.
DESCRIPTION
CODE
O Standby
C Compressor on (cooling or heat pump heat)
H High Gas heat on
h Low gas heat on
F Continuous fan on
10 1 Hour lockout
11 Failed ignition
12 Low flame sense
13 Flame lost
14 Unexpected flame
20 Twinning fault
22 Main limit open
26 Line and Neutral reversed
33 MRLC(Man. Reset limit cont.)(aka roll-out) open
G 44 Low Pres. Switch Closed
46 Low Pres. Switch Open, Indcr on low Speed
45 Low Pres. Switch Open, Indcr on High Speed
55 High Pres. Switch Closed
57 High Pres. Switch Open
58 Water Sensed Circuit Open
59 Water Sensed
61 Blower Fault - blower unable to run
93 Internal control fault
H - For Twinned units, check that both IFCs are set for "TWIN" and wire s
are connected between "TWIN" terminals .
- Check IFC*.
- For twinned units, ensure transformers are in phase.
(if out of phase, flame LED will be dim) .
- For non-twinned units, ensure "TWIN" is in the single (OFF) position.
- For Twinned units – ensure both IFC's have same part number .
- Check PS, PS Hoses, and wires.
F
- Check for blocked vent, excessive vent length or elbows, or
blocked heat exchanger .
- Check IDM wired correctly .
- Ensure against excessive wind, which can open pressure switch.
- Check for intermittent P.S. operation.
- Check switches and hoses for water or moisture.
- Check gas supply and manifold pressure.
- Ensure L1 and Neutral not swapped on IFC and junction box.
- Check igniter alignment .
- Check orifice or other restrictions to gas flo w.
- Check flame sense rod (clean with scotch brite pad).
- Check flame carry over.
- Check wires, continuity , and connection between IFC and gas valve.
- Ensure 24 V between appropriate pins on connector of IFC.
- Ensure manual switch on valve is in the "ON" position.
- Did a pressure switch open during ignition trial? If yes, go to F
- Did a limit open during ignition trial? If yes, go to D
NOTE: If IFC goes into lockout ("ST ATUS LED will blink code "1"), shut
off main power to unit, wait 30 seconds and then reset power .
CHECK:
-IDM
-IDM Capacitor
-Low Pres. Sw. wiring
-Hoses to Low Pres. Sw.
I
YES
PS dropping out ?
YES
GO TO
NO
F
CHECK:
- grounding on IFC and unit.
- check for proper polarity between L1 & neutral.
- flame sense rod (clean if necessar y).
- wire continually between flame sense rod and appropriate pin of
connector on IFC
- flame carries across all burners, and all burners stay lit.
- Check heat anticipator setting. Furnace may need an isolation relay.
- Check installation instructions under section titled "Isolation Relay" for
details .
- Verify correct furnace sizing.
- Check gas valve.
*Most failures are not due to the IFC. Doubl e
check all other possibilities, including the
ground connection or wire connections, before
replacing the IFC.
**System will attempt to light 4 times. Voltage
is present at gas valve for only 7 seconds dur -
ing each trial for ignition. The entire system will
go into a 1 hour lockout after 4 attempts.
Fault
Priority
24
22
21
19
23
13
15
14
16
2
20
4
17
3
6
9
8
7
11
10
12
18
1
NO
Check IFC*
E
ST-A1205-12-01