Suburban Water Heater: “No spark / no ignition”
warning RV water heater fault codes
What it means
The control board is powered and attempting to light (reset light cycling) but no spark is produced at the electrode, or spark is present but the burner never lights. The board will run its three trials and then lock out.
Most likely causes
- Electrode gap incorrect, electrode dirty/carbon-fouled, or cracked porcelain insulator most likely
- Loose, corroded, or shorted high-voltage electrode wire (including shorting to the closed appliance door) common
- Burner or orifice clogged with debris or spider webs common
- Defective module (control) board less common
Safe checks you can do yourself
- With gas and 12V OFF, inspect the electrode for a clean tip, intact porcelain, and roughly a 1/8 inch gap.
- Look for spider webs or debris in the burner tube and orifice.
- Check that the electrode wire is firmly connected and not pinched against the door or cabinet.
- Lightly clean the electrode tip with emery cloth if lightly fouled.
How to reset / clear No spark / no ignition
- After cleaning/correcting the electrode and wiring, turn the switch OFF for 5-10 seconds, then ON to restart the ignition cycle.
- Confirm the burner lights and stays lit; if it lights momentarily then drops out, the flame-sense (electrode) connection or gap is likely the issue.
When to call a technician
Spark and gas are both confirmed present but the burner won't sustain flame, or there is no spark after cleaning and a known-good wire/gap, indicating a failed board or valve.
Accuracy notes
Symptom-based fault from the factory chart, not a numeric display code. Correct electrode gap (1/8 in) and gas pressure (11-14 in WC) are the manual's reference values.
Applies to
SW6D · SW6DE · SW10D · SW10DE · SW12DE · SW16DE · SW6DEL · SW10DEL
FAQ
What does Suburban Water Heater code "No spark / no ignition" mean?
The control board is powered and attempting to light (reset light cycling) but no spark is produced at the electrode, or spark is present but the burner never lights. The board will run its three trials and then lock out.
How do I reset Suburban Water Heater No spark / no ignition?
After cleaning/correcting the electrode and wiring, turn the switch OFF for 5-10 seconds, then ON to restart the ignition cycle. Confirm the burner lights and stays lit; if it lights momentarily then drops out, the flame-sense (electrode) connection or gap is likely the issue.
What is the most common cause of No spark / no ignition on a Suburban Water Heater?
The most likely cause is electrode gap incorrect, electrode dirty/carbon-fouled, or cracked porcelain insulator.
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Sources
- Suburban Water Heater Service & Training Manual — DSI Troubleshooting Chart (NO SPARK / NO IGNITION / BURNER LIGHTS MOMENTARILY) — DSI Sequence of Operation & Troubleshooting Chart, p. 17 (Suburban (Airxcel/RV Comfort), via PDX RV Wholesale)
● Checked against 1 manufacturer document · Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual. How we verify