Suburban Water Heater Igniter: When It Needs Replacing
On this page (6 sections)
The Short Answer: On a Suburban direct-spark (DSI) water heater, the igniter is an electrode at the burner. Before blaming it, rule out what Suburban’s manual lists first: switch off, propane empty or off, or the ECO reset tripped. If the board clicks but no spark reaches the burner, the electrode or its wire is the likely fault. Replacing it is RV technician work.
How Suburban DSI ignition works
According to the SW6D/SW6DE manual (opens in a new tab), when you turn the switch on, the system tries to light the burner and, if it doesn’t light, makes two more tries before locking out. On three-try systems each try begins with a 15-second purge before the spark. To restart after a lockout, the manual says to turn the switch off, wait five seconds, and turn it back on. It also notes that the first start-up may need several ignition cycles to clear air from the gas lines.
Is it the igniter?
| What you notice at the exterior door | Likely cause |
|---|---|
| No clicking, no spark, nothing happens | Switch off, no 12-volt power, a blown fuse, the ECO tripped, or the board |
| Clicking you can hear, no spark visible at the burner | Electrode cracked, wire loose or damaged, or electrode out of position |
| Spark visible, no flame | Propane: empty cylinder, closed valve, frozen regulator, or a blocked burner or orifice |
| Lights, then goes out after a few seconds | Flame not being sensed: dirty or out-of-position electrode, or low gas pressure |
| Electric side heats, gas side doesn’t | Gas-side problem only; the electric element has its own circuit |
What you can check safely
- Smell. If you smell propane, stop, close the cylinders, and get everyone out of the RV.
- The checklist in the manual: switch on, propane cylinders open and not empty, and the ECO reset not tripped. See how to reset a Suburban water heater for the reset, and Suburban RV water heater not working on gas for the propane side.
- 12-volt power. A weak battery can make the board click without producing a strong spark. Try again on shore power or a charged battery.
- Look and listen at the exterior door during one ignition cycle. Note whether you see a spark at the burner and whether the flame appears.
- Look for nests or webs in the burner tube opening without reaching in.
Don’t remove the electrode, loosen gas fittings, or bend parts at the burner.
What the RV technician does
A technician turns off propane and power, then inspects the electrode for cracks in the ceramic and checks its position relative to the burner. They check the high-voltage wire and connections, clean the burner tube and orifice, and replace the electrode assembly with the part listed for your model and serial number. Afterward they test ignition and flame sensing and check for gas leaks at any fitting they disturbed. If a new electrode still doesn’t spark, the control board is next.
Repair or replace
An electrode is an inexpensive part. A control board costs more but is still a repair. The tank only needs replacing if it leaks.
Frequently Asked Questions
Q: Why does it light on the second or third try but not the first? A: Air in the gas line after a cylinder change is common; the manual says the first start-up may take several cycles. If it keeps happening, a dirty electrode or low propane pressure is likely.
Q: Does the electric element use the igniter? A: No. On SW6DE models the electric element has its own switch and thermostat, so the electric side can work while the gas side fails. See Suburban water heater not working on electric if it’s the other way around.
Manuals and supporting references
These links distinguish general safety information from model-specific documentation. A manual directory helps you locate your unit’s instructions; it does not establish that every model uses the same parts, codes, or test values.
- Suburban: SW6D/SW6DE/SW6DM/SW6DEM installation and operation manual (opens in a new tab)Suburban SW6D, SW6DE, SW6DM and SW6DEM direct-spark (DSI) RV water heaters.
- Suburban: service and support (opens in a new tab)Identify the appliance behind the RV badge and obtain its operating instructions.
- PG&E: recognizing and responding to a gas leak (opens in a new tab)Emergency actions for suspected fuel-gas leaks.
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