S9361A207X INTEGRATED BOILER CONTROLLERS
69-2751—05
14
TROUBLESHOOTING
IMPORTANT
1. The following service procedures are provided
as a general guide. Follow appliance manufac-
turer’s service instructions if available.
2. On lockout and retry models, meter readings
between gas control and ignition module must
be taken within the trial for ignition period.
Once the ignition module shuts off, lockout
models must be reset through the key buttons
and display. On retry models, wait for retry or
reset at the thermostat.
3. If any component does not function properly,
make sure it is correctly installed and wired
before replacing it.
4. The ignition module cannot be repaired. If it
malfunctions, it must be replaced.
5. Only trained, experienced service technicians
should service ignition systems.
Perform the checkout as the first step in
troubleshooting. Then check the appropriate
troubleshooting guide and the schematic diagram to
pinpoint the cause of the problem. If troubleshooting
indicates an ignition problem, see Ignition System
Checks below to isolate and correct the problem.
Following troubleshooting, perform the checkout
procedure again to be sure system is operating
normally.
Intermittent Pilot
Ignition System Checks
STEP 1: Check ignition cable.
Make sure:
• Ignition cable does not run in contact with any
metal surfaces.
• Ignition cable is no more than 36 in. [0.9 m] long.
• Connections to the ignition module and to the
igniter or igniter-sensor are clean and tight.
• Ignition cable provides good electrical continuity.
STEP 2: Check ignition system grounding. Nuisance
shutdowns are often caused by a poor or erratic
ground.
• A common ground, usually supplied by the pilot
burner bracket, is required for the module and the
pilot burner/igniter sensor.
—
Check for good metal-to-metal contact
between the pilot burner bracket and the main
burner.
—
Check the ground lead from the
GND(BURNER) terminal on the module to the
pilot burner. Make sure connections are clean
and tight. If the wire is damaged or deterio-
rated, replace it with No. 14-18 gauge, mois-
ture-resistant, thermoplastic insulated wire
with 105° C [221° F] minimum rating.
—Check the ceramic flame rod insulator for
cracks or evidence of exposure to extreme
heat, which can permit leakage to ground.
Replace pilot burner/igniter-sensor and
provide shield if necessary.
—If flame rod or bracket are bent out of posi-
tion, restore to correct position.
STEP 3: Check spark ignition circuit.
• Disconnect the ignition cable at the SPARK
terminal on the module.
WARNING
The ignition circuit generates over 10,000
volts and electrical shock can result.
Energize the module and listen for the audible
sparking noise. When operating normally, there
should be a buzzing noise that turns on and off twice
per second for a duration of 1–7 seconds, depending
on the model.
STEP 4: Check pilot and main burner lightoff.
• Set the system to call for heat by turning the
thermostat above room temperature.
• Watch the pilot burner during the ignition
sequence. See if:
—
Ignition spark continues after the pilot is lit.
—
The pilot lights and the spark stops, but main
burner does not light.
• If so, ensure adequate flame current as follows.
—
Turn off furnace at circuit breaker or fuse box.
—
Clean the flame rod with emery cloth.
—
Make sure electrical connections are clean and
tight. Replace damaged wire with moisture-
resistant No. 18 wire rated for continuous duty
up to 105° C [221° F].
—
Check for cracked ceramic insulator, which can
cause short to ground, and replace igniter-sen-
sor if necessary.
—
At the gas valve, disconnect main valve wire
from the MV terminal.
—
Turn on power and set thermostat to call for
heat. The pilot should light but the main burner
will remain off because the main valve actuator
is disconnected.
—
Check the pilot flame. Make sure it is blue,
steady and envelops 3/8 to 1/2 in. [10 to 13
mm] of the flame rod. See Fig. 9 for possible
flame problems and their causes.
—
If necessary, adjust pilot flame by turning the
pilot adjustment screw on the gas control
clockwise to decrease or counterclockwise to
increase pilot flame. Following adjustment,
always replace pilot adjustment cover screw
and tighten firmly to assure proper gas control
operation.
—
Set temperature below room setpoint to end
call for heat.
• Recheck ignition sequence as follows.
—
Reconnect main valve wire.
—
Adjust thermostat above room temperature.
—
Watch ignition sequence at burner.
—
If spark still doesn’t stop after pilot lights,
replace module.
—
If main burner doesn’t light or if main burner
lights but system locks out, check module,
ground wire and gas control as described in
appropriate troubleshooting chart.
Troubleshooting Error Codes
The integrated boiler control uses advanced
diagnostic capability to assist in troubleshooting error
conditions. Table 9 shows the codes that could arise
on the remote or integrated display during a fault.
Suggestions are provided in Table 5 for servicing these
potential errors.