The pilot light on a Ruud water heater that won’t stay lit is a common issue caused by gas supply problems, faulty components, or venting obstructions. This guide provides safe, step-by-step troubleshooting to identify and fix the root cause, with clear actions you can take before calling a professional. Each step explains potential reasons and practical remedies, helping homeowners restore hot water access efficiently and safely.

Initial Safety Checks And Quick Fixes

Begin with basic safety checks to rule out immediate hazards and simple solutions. Ensure the area around the water heater is well-ventilated and free of combustibles. If there is a hissing sound, unusual gas odor, or you feel dizzy, leave the area and contact your gas supplier or emergency services. If you can safely access the unit, verify the gas shutoff valve is fully open and the electrical disconnect switch is on, if applicable. A quick reset can sometimes resolve intermittent ignition issues.

Inspect The Pilot Assembly And Thermocouple

The pilot assembly and thermocouple are common culprits when a Ruud water heater won’t keep the flame lit. A dirty or misaligned thermocouple can falsely signal that it is not hot enough to sustain the gas valve. Begin by turning off the gas supply and power, then remove the access panel to view the pilot and thermocouple. Gently clean any dirt or soot from the pilot orifice with compressed air or a soft brush. Ensure the thermocouple tip is positioned correctly about 1/4 inch in front of the pilot flame. If the thermocouple is bent or visibly damaged, it should be replaced.

Check The Gas Supply And Pressure

A weak or inconsistent gas supply can cause the pilot light to extinguish. Confirm the main gas shutoff valve is fully open and inspect any exterior gas lines for leaks or kinks. If you have access to a gas pressure gauge and are trained to use it, test the line pressure to ensure it meets Ruud specifications for your model. Low incoming gas pressure or an obstructed gas line can prevent the pilot from staying lit. If you suspect pressure issues, contact your gas utility or a licensed technician for a thorough pressure test and adjustments.

Vent And Flue Blockage Assessment

Poor venting can cause exhaust backflow, leading to flame instability. Inspect the vent connector for obstructions, debris, or crushed sections. Look for signs of condensation or rust near the flue outlet, which can indicate improper venting. If the unit is located in a tight cabinet or closet, ensure there is adequate clearance for combustion air. A blocked or restricted flue often requires professional cleaning or vent replacement to restore proper draft.

Inspect For Condensate And Water Leaks

Moisture around the burner area or a damp control area can interfere with ignition electronics or gas valve operation. Check for water leaks from the tank, cold-water inlet, or drain valve that might affect sensor or electrical components. Any corrosion on burner components or junctions suggests moisture ingress and may necessitate part replacement or a more comprehensive service call.

Thermostat And Electronic Control Considerations

Ruud units with electronic controls may lose ignition stability due to incorrect thermostat settings or faulty control boards. Verify the thermostat is set to an appropriate temperature (often around 120°F) and cycling is enabled. If the unit features an LED diagnostic indicator, note any flashing codes and consult the Ruud manual or a technician for code interpretation. In some models, a faulty control board or safety switch can repeatedly shut off the gas supply even when the pilot is lit.

Pilot Orifice And Gas Valve Condition

Over time, mineral buildup or debris can clog the pilot orifice, preventing reliable ignition and flame sustainment. Clean the orifice using a fine wire or compressed air after de-energizing the unit. Inspect the gas valve for signs of wear or sticking. If the valve fails to maintain the pilot flame, replacement by a qualified technician is usually required. Do not force, loosen, or bypass safety components to force ignition, as this creates a serious risk of gas leak or explosion.

When To Call A Professional

Some signs indicate professional service is necessary: persistent ignition failure after cleaning and adjustments, frequent pilot extinction due to suspected gas pressure issues, visible damage to the burner assembly, or if you smell gas after attempting ignition. A licensed plumber or HVAC technician can perform a comprehensive diagnostic, including gas pressure testing, vent integrity assessment, thermocouple replacement, and control board evaluation. Regular maintenance, such as annual professional inspection, helps prevent pilot problems and extends system life.

Preventive Maintenance And Best Practices

To minimize future pilot issues, schedule routine maintenance, including cleaning the burner and pilot assembly every 1–2 years, inspecting the thermocouple for wear, and ensuring venting remains clear. Use the Ruud service manual for model-specific guidance and recommended parts. Keep the area around the water heater free of clutter to allow proper combustion air and venting. Consider installing a tankless monitoring system or smart diagnostics if available for your model to catch ignition issues before they impact hot water supply.

Summary Of Practical Steps

Perform a safety check: gas valve position, power status, and clear area.
Inspect and clean the pilot and thermocouple; adjust position if needed.
Verify gas supply pressure and look for leaks or obstructions.
Check venting for blockages and ensure sufficient combustion air.
Assess thermostat and electronic controls for correct settings and operation.
Clean or replace the pilot orifice and gas valve if necessary; involve a professional for valve work.
Call a licensed technician if the pilot still won’t stay lit after basic fixes.

Helpful Resources And How To Find A Technician

Consult Ruud’s official support portal for model-specific diagrams, parts lists, and troubleshooting steps. When seeking service, ask for a licensed HVAC technician with Ruud experience and confirm they can perform gas line tests, vent inspection, and thermocouple replacement. Keep model and serial numbers handy, along with any diagnostic codes observed on the control panel.