Suburban Water Heater: “No reset light”
warning RV water heater fault codes
What it means
On a DSI SW-series unit, the reset light failing to come on at all when the switch is turned ON indicates the control board is not getting power or the thermostat/ECO circuit is open, so no ignition sequence begins.
Most likely causes
- No or low 12V DC power at the ON/OFF switch (blown fuse, bad connection, low battery) most likely
- Gas-side ECO (high-limit) or thermostat is open, breaking the control circuit common
- Broken/loose wiring to the board or to the reset light, or a burned-out indicator bulb less common
- Defective module (control) board or switch/lamp assembly less common
Safe checks you can do yourself
- Confirm 12V DC (about 10.5-13.5V) is present at the water-heater ON/OFF switch.
- Check and replace the 12V fuse for the water heater in the RV power center if blown.
- Press the gas-side (right-hand) ECO reset button on the front face under the rubber cover in case the high-limit has tripped.
- Confirm battery/converter is supplying good voltage.
How to reset / clear No reset light
- Restore 12V power (replace fuse, tighten connections, charge battery).
- Reset the gas ECO if it was tripped.
- Cycle the switch OFF then ON and confirm the reset light now illuminates.
When to call a technician
Power is confirmed at the switch but the light still won't come on, pointing to a failed board or switch/lamp assembly, or wiring you cannot trace.
Applies to
SW6D · SW6DE · SW10D · SW10DE · SW12DE · SW16DE · SW6DEL · SW10DEL
FAQ
What does Suburban Water Heater code "No reset light" mean?
On a DSI SW-series unit, the reset light failing to come on at all when the switch is turned ON indicates the control board is not getting power or the thermostat/ECO circuit is open, so no ignition sequence begins.
How do I reset Suburban Water Heater No reset light?
Restore 12V power (replace fuse, tighten connections, charge battery). Reset the gas ECO if it was tripped. Cycle the switch OFF then ON and confirm the reset light now illuminates.
What is the most common cause of No reset light on a Suburban Water Heater?
The most likely cause is no or low 12v dc power at the on/off switch (blown fuse, bad connection, low battery).
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Sources
- Suburban Water Heater Service & Training Manual — DSI Troubleshooting Chart (NO RESET LIGHT) — DSI Sequence of Operation & Troubleshooting Chart, p. 17 (Suburban (Airxcel/RV Comfort), via PDX RV Wholesale)
Note: Not a numeric code; this is an indicator-light state described in the factory troubleshooting chart.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.