Honeywell Electronic
Ignition Troubleshooting
The Honeywell S8610H Intermittent Pilot Module provides the ignition sequencing, pilot spark, pilot flame
monitoring, Pilot Valve (PV) control, Main Valve (MV)
control, and safety LOCKOUT for gas fueled hot water
pressure washers. It is used with a Honeywell 24V gas
valve and a pilot burner/ignitor-sensor. The PN’s for
these common components are listed at the end of this
tech tip.
When 24 VAC is applied to the module 24V terminal
it outputs 24 VAC on the PV terminal, outputs 10,000
Tech Tip
April 2007
VAC on the SPARK terminal, and starts the LOCKOUT timer. If the pilot ignites before the LOCKOUT
timer expires (15 or 90 seconds based on model) the
module stops the spark and outputs 24 VAC on the
MV terminal. If the pilot does not ignite during this time
period then the module will LOCKOUT. This removes
the voltage from the PV and SPARK terminals. To clear
the LOCKOUT, cycle the input voltage OFF/ON to the
24V terminal. This will start the sequence over again.
See Simple Electronic Ignition Wire Diagram below.
SIMPLE ELECTRONIC IGNITION WIRE DIAGRAM
IGNITION MODULE
S8610H
BURNER SWITCH
24V (6)
24 VAC
LIGHT
THERMOSTAT
24V (GND) (5)
GAS VALVE
VR8304M4002
FLOW SWITCH
OR PRESSURE
SWITCH
(1) MV
MV
(2) MV/PV
MV/PV
(3) PV
PILOT BURNER/IGNITOR - SENSOR
Q345A
(9) SPARK
IGNITOR ROD
(4) GND (BURNER)
CHASSIS GND
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PV
TECH TIP
To use this troubleshooting table start from the top and continue down the table until your problem is found.
Required test equipment:
•
Digital Multimeter – Used to measure VOLTS AC and OHMS.
•
Manometer (Range 0 – 16 Water Column Inches) – Used to measure gas pressure.
•
High Voltage Test Lead – You will need a short jumper wire made from ignition cable or
other heavily insulated wire – Used to test spark gap.
Problem
Possible Cause
Recommended Action
Burner Light on Control No 24 VAC
Panel does not light
• Verify stepdown transformer(s) voltages input and output.
• Verify associated fuses.
• Verify associated wires, connections, and switches
Replace as required.
No spark at ignitor rod
Ignition Module in
LOCKOUT
• Reset by cycling burner switch OFF / ON.
Bad ignition cable
• Measure resistance of ignition cable. It should be < 2 ohms.
Replace as required.
Bad Ignition Module
Check spark ignition circuit.
• Disconnect ignition cable from SPARK terminal on ignition
module.
• Connect one end of High Voltage Test Lead (see Required
Test Equipment) to chassis ground.
• Turn Burner Switch to ON. Immediately move the free end
of the High Voltage Test Lead toward the SPARK terminal
until a spark is established.
• Slowly pull High Voltage Test Lead away from the terminal
and note the length of the gap when sparking stops.
No arc or <1/8” – Replace ignition module.
Bad Pilot Burner /
Ignitor-Sensor
• Verify Pilot Burner / Ignitor-Sensor is well grounded.
Good ground wire, and connections.
• Clean ignitor rod tip and hood above the tip with emery cloth.
• Verify Pilot Burner / Ignitor-Sensor high voltage insulator is
not cracked.
• Verify hood above ignitor is ~ 1/8" from tip of ignitor.
Adjust or replace as required.
No gas
•
•
•
•
Pilot will not light
– have spark
Verify gas valve knob is in ON position (if equipped)
Verify gas supply ball valve is open
Verify pilot tube ball valve is open
Try to light the pilot with an external flame when the ignitor
is sparking.
• Verify no gas leaks.
• Verify gas and pilot lines are bled of air.
• Measure incoming gas pressure. It should be 10-14 WCI.
Correct as required.
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TECH TIP
Problem
Possible Cause
Recommended Action
Pilot will not light
– have spark (cont.)
Plugged pilot orifice
• Remove pilot tube from Pilot Assembly, remove the pilot
orifice and observe for obstructions.
Repair or replace as required.
Pilot Valve is not open • Verify 24 +/- 3.5 VAC between PV and MV / PV terminal at
the gas valve. If out of tolerance, verify voltage again at
ignition module.
If VAC out of tolerance - Replace ignition module, wires, and
connections as required.
Pilot lights - but then
goes out
Spark not hot enough
to light pilot gas
• Clean ignitor rod tip and hood above the tip with emery
cloth.
• Measure resistance of ignition cable. It should be < 2 ohms.
• Verify gas is at pilot by lighting the gas with an external
flame (i.e. butane barbeque lighter).
If pilot lights with external flame replace ignition cable or reroute it with insulated standoffs away from the cabinet chassis
as required.
If pilot does not light with external flame replace gas valve.
Possible ground
problem
• Verify no corrosion on mounting hardware and wire
connections.
• Verify ground wire integrity between pilot assembly, gas
valve, and ignition module GND (Burner).
If ground problem repair or replace as required.
Ignition Module is not
sensing lit pilot
• Clean pilot assembly ignitor rod tip and hood above the tip
with emery cloth.
• Monitor 24 VAC between PV and MV / PV. If it goes to
0 VAC in the time period marked on the S8610H label then
the ignition module is in LOCKOUT. It did not sense the pilot
light being lit.
Replace ignition cable, pilot assembly, and ignition module as
required.
Gas problems
• Verify incoming gas pressure is between 10 -14 WCI and
does not vary when the pilot first lights. It should remain
constant.
If out of tolerance, troubleshoot and repair as required.
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TECH TIP
Problem
Possible Cause
Recommended Action
Main burner does not light
– pilot is lit
Ignition Module
• Verify 24 +/- 3.5 VAC between ignition module
terminals MV and MV / PV.
If out of tolerance replace ignition module.
Operator Error
• Verify thermostat is dialed to max temperature
(if equipped)
• Verify trigger gun is open and water is flowing
Temperature and Flow
sensing devices
• Verify 24 +/- 3.5 VAC between gas valve terminals
MV and MV / PV.
If out of tolerance troubleshoot to open circuit in wiring,
flow device (flow switch or pressure switch), or temperature sensing device (thermostat or snap switch).
Main burner is lit – then
goes out
Gas Problem
• Verify incoming gas pressure. It should be
10-14 WCI.
• Verify manifold (gas valve outlet) gas pressure.
It should be 3-5 WCI for NG and 10-13 WCI for LP.
Repair and replace as required. Gas valve may be bad.
Gas Problem
• Monitor incoming gas pressure. It should remain
within 4 WCI of the reading with the gas valve closed.
• Monitor manifold (gas valve outlet) gas pressure. It
should be 3-5 WCI for NG and 10-13 WCI for LP.
Troubleshoot gas valve or gas problem.
Pilot blows out
• Observe pilot flame when main burner is first lit. If it
blows out then the ignition module will shut off voltage
to MV and re-start sparking and pilot ignition.
Shield pilot with non-flammable material to protect the
flame from severe in-rush air currents.
Ignition Module
• Module removes 24 VAC at MV terminal due to
malfunction, loss of pilot, or loss of pilot sense.
Troubleshoot, repair, and replace as required.
Temperature and Flow
sensing devices
• Verify 24+/- 3.5 VAC between gas valve terminals
MV and MV / PV.
If out of tolerance or intermittent troubleshoot to open
circuit in wiring, flow device (flow switch or pressure
switch), or temperature sensing device (thermostat or
snap switch).
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TECH TIP
Hotsy Part Numbers
Description
Part Number
Ignition Module
7-701510
Gas Valve Natural Gas
7-700021
Conversion of Gas Valve to Liquid Propane
7-702320
Pilot Burner / Ignitor – Sensor
7-702371
Ignition Wire 60”
6-01353
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