Suburban Water Heater: “Gas valve won't open”
warning RV water heater fault codes
What it means
The board is sequencing and spark is present, but the gas valve fails to open so no fuel reaches the burner and the unit cannot light. Diagnosed by checking for voltage to the valve during the trial-for-ignition and by gas-pressure and solenoid-resistance tests.
Most likely causes
- Insufficient or no LP gas pressure (the manual references 11-14 inches WC) most likely
- Low or missing voltage (10.5-13.5V DC) on the wire to the gas valve during ignition common
- Open or shorted gas-valve wire less common
- Failed gas-valve solenoid (out-of-range resistance, manual references ~30-50 ohms) less common
Safe checks you can do yourself
- Confirm the propane tank has fuel and is turned on, and that the regulator is functioning.
- Confirm 12V power is healthy at the unit.
- Check that no inline gas valves or the bypass are closed.
How to reset / clear Gas valve won't open
- After confirming gas and 12V, cycle the switch OFF for 5-10 seconds then ON to retry ignition.
When to call a technician
Gas supply and 12V are confirmed good but the valve still won't open; pressure/solenoid testing or valve replacement is needed.
Applies to
SW6D · SW6DE · SW10D · SW10DE · SW12DE · SW16DE · SW6DEL · SW10DEL
FAQ
What does Suburban Water Heater code "Gas valve won't open" mean?
The board is sequencing and spark is present, but the gas valve fails to open so no fuel reaches the burner and the unit cannot light. Diagnosed by checking for voltage to the valve during the trial-for-ignition and by gas-pressure and solenoid-resistance tests.
How do I reset Suburban Water Heater Gas valve won't open?
After confirming gas and 12V, cycle the switch OFF for 5-10 seconds then ON to retry ignition.
What is the most common cause of Gas valve won't open on a Suburban Water Heater?
The most likely cause is insufficient or no lp gas pressure (the manual references 11-14 inches wc).
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Sources
- Suburban Water Heater Service & Training Manual — DSI Troubleshooting Chart (GAS VALVE DOESN'T OPEN) — DSI Sequence of Operation & Troubleshooting Chart, p. 17 (Suburban (Airxcel/RV Comfort), via PDX RV Wholesale)
Note: Symptom-based fault. The voltage/pressure/resistance figures are the manual's diagnostic reference values, not user-serviceable settings.
● Last verified 2026-06-29 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual.