If your Honeywell S8610U ignition control is flashing, record the pattern before resetting the system. The LED identifies a control state and points to checks; it does not prove that a particular part has failed. Use the code and symptom to narrow the diagnosis, but leave live electrical, gas-pressure, flame-current, valve, and control-replacement work to a qualified service technician.
What the S8610U does—and what it does not fit
The S8610U is a flame-rectification intermittent-pilot gas ignition control. It sequences ignition, monitors the pilot flame, and shuts off gas as a safety measure in certain warm-air furnaces, residential boilers, and other natural- or LP-gas appliances. Its documented configurations include single-rod local sensing and two-rod remote sensing. Resideo’s installation instructions exclude standing-pilot appliances, direct-main-burner ignition, and systems that do not use flame rectification.
Before considering a replacement, compare the appliance wiring diagram, original control, cross-reference information, and specifications. The S8610U is not a universal fit for every gas appliance. Resideo lists the S8610U3009/U as a replacement for certain intermittent-pilot controls, but fit must be confirmed for the specific appliance and original module. See the official product listing.
How to read the status LED
Resideo defines a flash code as a repeating sequence: the listed number of flashes at 2 Hz, a two-second pause, then a repeat. A heartbeat is a repeating half-second bright and half-second dim cycle. In run mode, a four-second on pulse followed by flashes indicates flame current to the nearest microamp.
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- 【Compatibility】This product is compatible with a variety of device models, including Honeywell S8610U3009, Honeywell S8610U1003 and S8610u honeywell ignition module It is compatible with numerous products from brands such as Honeywell, Johnson and Robert Shaw, and is suitable for various gas stove systems.
- 【Intelligent Design】S8610u furnace control board is equipped with a flame monitoring function. If ignition fails within 6 minutes, it will automatically cut off the gas supply completely, effectively preventing leaks and ensuring safe and reliable operation. It supports single-barrel, double-barrel and remote sensing configurations.
- 【Plug and Play】S8610u ignition control module is designed as a plug-and-play alternative, compatible with the original factory interfaces and wiring, which can save maintenance time and costs. However, to ensure safety and proper matching, it is recommended that professional HVAC technicians carry out the installation operation.
- 【General Gas Adapter】Supports natural gas and liquefied petroleum gas. Powered by 24V AC. Without pre-blowing design. Supports adjustable ignition timing of 30 seconds. Satisfies diverse installation requirements.
- 【Quality Assurance】 Made with high-quality materials and meticulously designed and manufactured, the structure is compact and sturdy. It has been rigorously tested to ensure durability and long lifespan. It has excellent anti-interference and environmental adaptability, and can operate stably under complex conditions.
| LED indication | What it indicates | Manufacturer-listed direction |
|---|---|---|
| Off | No call for heat. | Check whether the appliance is calling for heat before treating this as a fault. |
| Rapid flashing | Power-up internal check. | Allow the startup check to complete. |
| Heartbeat | Normal startup or ignition sequence, including any configured prepurge. | Observe whether the sequence progresses to ignition. |
| Four-second on pulse, then flashes | Run mode; flashes show flame current to the nearest µA. | Use the manufacturer’s technician procedure if flame-current diagnosis is needed. |
| 2 flashes | Pilot flame was not detected during trial for ignition; control is in retry delay. | If the next trial fails, check gas supply, pilot burner, spark and flame-sense wiring, flame-rod contamination or position, and burner ground. |
| 3 flashes | Flame failed during run; control starts a new trial. | If it fails again, check gas supply, pilot burner, flame-sense wiring, flame rod, and burner ground. |
| 4 flashes | Flame sensed out of sequence. | Check whether pilot flame is present and follow the manual’s guidance for fault persistence and appliance response. |
| 5 flashes | Vent-damper error, such as a required damper missing or failing to open or close within the specified time. | Check damper connection and wiring, and the control’s 24 V connection. |
| 6 flashes | Internal control error. | Cycle the call for heat; if the error repeats, the manual directs replacement of the control. |
| 7 flashes | Flame rod shorted to ground. | Check for a damaged or shorted lead, incorrect rod position, or cracked, damaged, or tracked ceramic. |
| 8 flashes | Low secondary voltage. | Have a technician check the transformer and AC line voltage at the control with the full system load on the transformer. |
A retry code describes an unsuccessful ignition trial, not a confirmed failed module. In particular, codes 2 and 3 direct attention to the pilot, gas supply, spark or sensing circuit, and ground before the control is blamed.
Start with the symptom
No spark, or the pilot does not light
Record the LED indication and compare the appliance’s startup behavior with the manufacturer’s sequence. Resideo’s troubleshooting chart asks whether the module has nominal 24 V power, whether the pilot lights, and whether spark reaches the igniter-sensor gap. Technician checks can include line-voltage supply, the low-voltage transformer, limit controller, thermostat, wiring, combustion-air proving switch, and vent-damper end switch. The chart also identifies ignition-cable continuity, burner ground, ceramic insulation, spark gap, open manual gas valves, supply pressure, pilot tubing, and a blocked pilot orifice as possible diagnostic areas.
Rank #2
- Resideo (Honeywell spun off it's residential division in 2018. Newer units are labeled Resideo
- This controller provides ignition sequence, flame monitoring, and safety shutoff for intermittent pilot central furnaces, residential boilers, and other heating appliances
- This control module is NOT designed to replace controls in applications with: Flame Sensing other than by flame rectification, standing pilot appliances, direct main burner ignition
- On this model, unlike previous Honeywell S86XXXX models, the transformer secondary hot (switched leg- call for heat from thermostat) goes to terminal TH-W and NOT to terminal 24V in most cases, if there is not automatic vent damper. See accompanying documentation for details
The manual warns that spark testing involves an ignition circuit generating more than 10,000 volts. Do not attempt live spark or voltage tests as a homeowner quick fix.
Pilot lights, but spark continues or the main burner does not light
Resideo’s technician checks include flame current, clean and tight connections, flame-rod cleanliness and position, a cracked ceramic insulator, ignition-cable condition, pilot-flame quality and coverage, and the shared burner ground. The manual describes a steady blue pilot flame covering approximately 3/8 to 1/2 inch (10 to 13 mm) of the flame rod during its service check. If the main burner does not light, the manual also directs technicians to check gas-control and module wiring.
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Rank #3
- S8610U3009 Intermittent Pilot Control replaces: S8600F1000, S8600F1034, S8600F1042. This is the direct replacement for Slant/Fin 411-873-000 and 411-872-000
- S8610U Furnace Control Board Module, provides ignition sequence, flame monitoring and safety shutoff for intermittent pilot central furnaces and heating appliances
- Furnace replacement circuit board compatible with Honeywell. Field service replacement for most Honeywell, Robertshaw, Johnson, and UTEC (HSC) Intermittent Pilot Ignition Modules
- For use with Natural or LP gas. Functional equivalent of S86, S8600, S8610 and S90 modules. Includes spark cable adapters to allow field replacement of both Honeywell and competitive controls without replacing existing spark cable
- For use in single rod or dual rod or remote sense applications, Configurable to 30 sec, Universal Pilot Ignition Module, Intermittent, 24 V AC, Replaces over 400 White-Rodgers, Robertshaw and Honeywell intermittent pilot ignition modules, Provides 100 percent pilot gas shutoff if pilot fails to light after 6 min delay, No prepurge
The appliance lights, then shuts down or retries
A code 3 means flame was lost during run; the control initiates another trial. If the problem recurs, use the code’s listed checks—gas supply, pilot burner, flame-sense wiring and rod, and burner ground—as diagnostic leads rather than replacing parts by guesswork. Poor grounding and flame-sensing problems are among the causes identified in the manufacturer’s troubleshooting guidance.
What the manufacturer’s timing and flame-current figures mean
The figures below are from Resideo Technologies, Inc., installation instructions 69-1955—10 SA, revision 1-26 (2026). They describe this control and its service procedure, not independent performance testing.
Rank #4
- Compatible Replacement: Furnace ignition control board compatible with Honeywell S8610U3009, S8610U1003, and Resideo systems (post-2018 models).
- Functionality: Manages ignition sequence, flame monitoring, and safety shutoff for intermittent pilot furnaces and residential boilers.
- Compatibility Note: Not for standing pilot systems, direct burner ignition, or non-rectification flame sensing applications.
- Installation: Wiring differs from older S86XXXX models—refer to documentation for TH-W/24V terminal connections.
- Universal Use: Works with natural or LP gas; includes part number S8610U for easy identification.
- Retry delay: After a failed trial for ignition, the manual specifies a five-minute delay before another trial. Trials continue after that delay until the pilot is lit and proved or the call for heat ends.
- Trial for ignition: The control can be configured for a 15- or 90-second trial using DIP switches. Verify the setting against the appliance and original control; do not change it casually.
- Flame current: In the manual’s pilot-only procedure, the steady minimum is 1 µA DC or 1 V DC, and 2 µA or 2 V DC or more is recommended for reliable operation. The procedure calls for the pilot valve to be lit with no main gas flowing and the MV leadwire disconnected from the control. A voltmeter reading in volts corresponds to flame current in microamps under that method. This is a technician measurement, not a consumer repair step.
- Ignition cable: The manual’s cable check addresses lengths up to 36 inches (0.9 m).
Safe troubleshooting and when to call a technician
Resideo’s instructions state: “Only trained, experienced service technicians should service intermittent pilot systems.” The troubleshooting chart is general guidance; follow the appliance manufacturer’s service instructions where available. Stop at recording the symptom and LED pattern if diagnosis would require opening the appliance or testing a live circuit.
- Do not perform live electrical or spark tests, adjust gas pressure, test flame current, service a gas valve, or replace the ignition module yourself.
- Give the technician the LED pattern, whether the pilot lights, whether the main burner starts, and when the shutdown or retry occurs.
- Ask that the appliance wiring diagram, original control, fuel, and sensing configuration be checked before replacement parts are selected.
Resideo states that the ignition control module cannot be repaired; if it malfunctions, it must be replaced. That makes accurate diagnosis and compatibility checks important: a code alone is not enough to identify the failed component.
Best Value
- Precise Adjustment: Control board module can accurately control the heating process, making temperature adjustment more stable and reliable, without worrying about overheating or insufficient heating, during long-term use, it brings a more comfortable experience for your operation
- Security Protection: Furnace control board module has multiple built-in security mechanisms, making the equipment more reliable during use, the multi-layer protection design provides you with a reassuring user experience
- Compatible Models: Fit for Honeywell S8610U3009 S8610U1003 and resideos ystems 2018 and later models, replace S8610U, compatible with multiple models to meet your different needs
- Wear Resistance: Boiler plate module is made of high-quality materials and maintains stable performance even during long-term use, it can withstand frequent operation and high temperature environments, extending the overall service life of the equipment, the stable and wear-resistant characteristics ensure that your equipment operates efficiently for a long time
- Easy Installation: The installation process is fast and smooth, even for first-time use, it can easily complete the installation of the furnace control board module without complex tools and installation skills, without additional adjustments, shortening installation waiting time, and improving usage efficiency
Choosing a replacement or cable
Resideo lists the S8610U3009/U module and two ignition cable assemblies. The listed 394800-30/U cable is 30 inches with a right-angle boot; the 394801-30/U is 30 inches with a straight boot. These accessories are relevant only if a cable is damaged or unsuitable and the appliance connection matches. Confirm the exact appliance application and original-control cross-reference before ordering or fitting any part using Resideo’s product information and the appliance instructions.
Quick Recap
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