Reznor PDH Operation Manual PreevA - Manual (Page 34)

Form O-PreevA, Page 34
4.0 Troubleshooting
(cont'd)
4.2 Troubleshooting - Modulating Control Module used on
Model RDH, RHH, or SHH with Opt AG58 or D12G (cont'd)
Gas Heat Section Modulating Control LOCKOUT ERRORS (cont'd)
Code Alert Description Probable Causes Solutions
Gas
Sensor
Failure
(EO6)
Pressure
Sensor
Reading
Low
The gas transducer
reading is too low
compared to the
expected value for the
modulating gas valve
actuator position.
When the furnace is
operating at 75% or
higher -- greater than
8 VDC analog input
voltage - the manifold
pressure sensor must
read 1.4" w.c. or higher
A. Modulating actuator/ball valve
not properly aligned
1 Perform modulating system gas valve alignment procedure; see
Paragraph 4.3.
B. Line pressure too low 1. Ensure line pressure is properly adjusted for the gas and
application. Correct as needed.
C. Intermediate regulated
pressure to low
1. Ensure the safety gas valve(s) are properly adjusted to the
specified outlet pressure. Adjust per the installation instructions
as necessary.
D. Wrong gas pressure sensor
installed.
1. Ensure the proper gas transducer - either natural gas or
propane - is installed. Replace as needed.
E. Gas pressure sensor faulty 1. Ensure gas manifold transducer is installed properly and wired
per the unit wiring diagram. Replace as necessary.
Gas
Sensor
Failure
(EO7)
Pressure
Sensor
Reading
High
The gas transducer
reading is too high
compared to the
expected value for the
modulating gas valve
actuator position.
When the furnace is
operating at 75% or
lower - less than 8 VDC
analog input voltage
-- the manifold pressure
sensor must read 2.8"
w.c. or lower.
A. Modulating actuator / ball
valve not properly aligned
1. Perform modulating system gas valve alignment procedure;
see Paragraph 4.3.
B. Line pressure too high 1. Ensure the line pressure is properly adjusted for the gas and
application. Correct as necessary.
C. Intermediate regulated
pressure too high
1. Ensure the safety gas valve(s) are properly adjusted to the
specified outlet pressure. Adjust per the installation instructions
as necessary.
D. Wrong gas pressure sensor
installed
1. Ensure gas sensor -- either natural or propane -- is installed.
Replace as necessary.
E. Gas pressure sensor faulty 1. Ensure gas sensor is installed properly and wired per the unit
wiring diagram. Replace as necessary.
Improper
Flame
Signal
(EO8)
Control senses flame
present when the gas
valve is commanded
off.
A. Flame remains lit in “Off” cycle 1. Gas valve leaks - check wiring to remove continuous 24V to
gas valve.
2. Gas valve is stuck open – remove, repair, or replace gas valve.
No Firing
Rate Input
(EO9)
Call for heat is sensed
(R & W closed) but
firing rate is below
defined voltage
threshold for furnace
operation.
A. Faulty wiring into the “Analog
+” and “Analog –“ terminals
1. Ensure wiring is connected per unit wiring diagram.
2. Check for loose pins or bad connections.
3. Check for frayed wiring or shorts to ground.
B. No signal from source. 1. Check firing rate input voltage – must be greater than 1.5 VDC.
2. Troubleshoot controller providing firing rate input to the deep
modulation ignition control board.
Invalid I.D.
Plug (Eid)
The installed I.D. plug is
not valid for this control
board.
A. Incorrect I.D. plug installed 1. Ensure I.D. plug is correct for the furnace – check label.
2. Ensure I.D. plug is properly inserted into the mating connector
on the control board.
3. With the I.D. plug installed, cycle power to the furnace. The
board will display the I.D. plug identity upon power-up.
4. Install correct I.D. plug as needed.
4.3 Troubleshooting - Blower Section (All Models - SDH, PDH, RDH, PEH, REH, RHH,
SHH, PXH, RXH) and Gas-Fired Heat Section (SDH, PDH, RDH, RHH, SHH)
PROBLEM PROBABLE CAUSE REMEDY
Venter motor
will not start
- Models SDH/
PDH/RDH/SHH/
RHH
1. No power to unit. 1. Turn on power; check supply fuses or main circuit breaker.
2. No 24 volt power to integrated circuit
board.
2. Turn up thermostat; check control transformer output.
3. Integrated circuit board fuse blown. 3. Correct cause. Replace fuse (type ATC or ATO, 32VDC, 3A).
4. No power to venter motor. 4. Tighten connections at circuit board and/or motor and terminals. Check venter
motor capacitor.
5. Integrated circuit board defective. 5. Replace integrated circuit board.
6. Venter motor capacitor defective. 6. Replace venter motor capacitor.
7. Defective venter motor. 7. Replace venter motor. NOTE: Manufacturer recommends replacing capacitor
when replacing venter motor.
Burner will not
light - Models
SDH/PDH/RDH/
SHH/RHH
1. SHH - Vent temperature switch activated. 1. Identify reason (see Paragraph 3.4.6, page 16) and correct. Reset switch.
2. SHH - Heat exchanger condensate drain
pressure switch activated.
2. Clean condensate drain. Verify flow. Fill traps with water and restart heater.
3. Manual valve not open 3. Open manual valve.
4. Air in the gas line. 4. Bleed gas line (initial startup only).
5. Gas pressure too high or too low. 5. Supply pressure should be 5-14” w.c. for natural gas or 11-14” w.c. for propane.
6. No Spark: 6.
a) Loose wire connections. a) Be certain all wire connections are solid.
b) Transformer failure. b) Be sure 24 volts is available.
c) Incorrect spark gap. c) Maintain spark gap at 1/8”.