Suburban Water Heater: “Gas ECO tripped”
warning RV water heater fault codes
What it means
The gas-side ECO (Energy/Electric Cut Off, a high-limit thermostat) on the 12V DC gas circuit has opened because water temperature exceeded its limit, cutting the gas control circuit. The unit will not light until the ECO is manually reset. On the SW front face this is the right-hand reset button under the rubber cover.
Most likely causes
- Gas thermostat failed to shut off the burner, so the high-limit ECO tripped as a safety backup most likely
- Low water level / air pocket against the ECO sensor causing a false over-temp common
- ECO/thermostat assembly itself degraded and tripping early less common
Safe checks you can do yourself
- Confirm the tank is full of water before attempting any reset.
- Locate the rubber cover on the front face; press the right-hand button (gas/12V ECO) to reset.
- If it trips again soon after reset, suspect a failing thermostat.
How to reset / clear Gas ECO tripped
- Make sure the tank is full and the water has cooled.
- Lift the rubber cover on the water-heater front and firmly press the right-hand (gas/12V) reset button.
- Restart the unit and verify it cycles off normally at temperature.
When to call a technician
The gas ECO trips repeatedly even with a full tank and cool water, which indicates a failing thermostat/ECO assembly that should be replaced.
Applies to
SW6D · SW6DE · SW10D · SW10DE · SW12DE · SW16DE · SW6DEL · SW10DEL
FAQ
What does Suburban Water Heater code "Gas ECO tripped" mean?
The gas-side ECO (Energy/Electric Cut Off, a high-limit thermostat) on the 12V DC gas circuit has opened because water temperature exceeded its limit, cutting the gas control circuit. The unit will not light until the ECO is manually reset. On the SW front face this is the right-hand reset button under the rubber cover.
How do I reset Suburban Water Heater Gas ECO tripped?
Make sure the tank is full and the water has cooled. Lift the rubber cover on the water-heater front and firmly press the right-hand (gas/12V) reset button. Restart the unit and verify it cycles off normally at temperature.
What is the most common cause of Gas ECO tripped on a Suburban Water Heater?
The most likely cause is gas thermostat failed to shut off the burner, so the high-limit eco tripped as a safety backup.
Related · Suburban water heater
Suburban gas (DSI) water heaters do not show a numeric fault… Electric ECO tripped
On gas/electric (DE) models, the 120V electric heating circu… Electric element no heat
On gas/electric models, the 120V element produces no heat or… Gas valve won't open
The board is sequencing and spark is present, but the gas va… No reset light
On a DSI SW-series unit, the reset light failing to come on … No spark / no ignition
The control board is powered and attempting to light (reset …
Sources
- Suburban Water Heater Service & Training Manual — DSI Troubleshooting (Reset ECO if open) and Thermostat & ECO Assembly — DSI Troubleshooting Chart p. 17; Thermostat & ECO Assembly p. 21 (Suburban (Airxcel/RV Comfort), via PDX RV Wholesale)
- Water Heater Troubleshooting & Repair (Suburban) — Hi-Limit/ECO Switch and Thermostat Assembly — Troubleshooting LP Mode, Hi-Limit/ECO section, pp. 6, 12 (Heartland Owners Forum)
Note: On Suburban SW units there are two reset buttons under one rubber cover: right-hand = gas/12V ECO, left-hand = electric/120V ECO. Button orientation can vary by model; confirm against the unit's own labeling.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.