Keep gas appliances lighting safely and reliably with thermocouples at Ace Hardware that sense flame and shut off fuel when the flame goes out. Whether you’re servicing a water heater, furnace or boiler, the right replacement helps restore dependable pilot performance and peace of mind.
How Do Thermocouples Work?
A thermocouple is a small safety sensor made from two dissimilar metals joined at the tip. When the tip sits in a pilot or burner flame, it generates a small millivolt signal that keeps the gas valve open. If the flame is lost, the signal drops and the valve closes, stopping gas flow. This simple, proven design helps prevent unburned gas from accumulating in your appliance.
When Should You Replace a Thermocouple?
Thermocouples are common on standing‑pilot gas water heaters and appear on many furnaces, space heaters and boilers. Over time, heat cycles, vibration and corrosion can reduce performance and make pilots harder to keep lit. Use the checklist below to spot signs it’s time to replace your thermocouple.
- The pilot light won’t stay lit after you release the control knob.
- The appliance shuts off during operation even though the pilot looked steady.
- The thermocouple tip shows heavy scale, corrosion or physical damage.
- Connections at the gas valve are loose, kinked or visibly worn.
How to Select the Right Thermocouple
A few quick checks help you match a replacement to your appliance and get back up and running faster.
- Length and routing: Measure from the gas valve to the pilot assembly and choose a length that matches your original path without sharp bends.
- Connection type: Confirm the thread size and mounting style at the gas valve and pilot bracket so the new part seats securely.
- Millivolt rating: Most residential thermocouples are 30 mV. Verify your appliance requirements in the owner’s manual.
- Appliance fit: Universal thermocouples cover many water heaters, furnaces and boilers, while some models specify brand‑specific kits for best fit.
Find dependable options from brands including Honeywell Home and Eastman, in common lengths and connection styles to fit popular gas water heaters and heating equipment.
Complementary Heating and Cooling Essentials
Round out your heating repair with complementary parts that help keep systems safe and efficient.
- Add HVAC controls to fine tune temperature, schedules and fan settings
- Replace radiator vents and valves to balance steam or hot water heat room by room
- Refresh dryer and vent hoses with clamps and exterior wall caps to maintain strong airflow and reduce lint
- Install igniters for furnaces and water heaters to restore reliable starts
Choose components that match your system voltage, thread size and hose diameter, and look for durable, code compliant materials to make installation smooth and long lasting.
Shop Thermocouples Near You at Ace Hardware
Find the right thermocouple replacement near you online and at your local Ace. Our helpful team can assist with length and connection selection, plus related items like pilot tubing, leak‑detection solution and basic hand tools to complete the job. From quick fixes to seasonal tune‑ups, Ace makes it easy to restore safe, reliable operation.
