Should a thermocouple be in the flame?
The pilot flame should touch the thermocouple at a specific level. If the flame is blue and weak, and barely reaches the thermocouple, it needs to be stronger. If it extends well above the thermocouple, it’s too strong.
How much flame does a thermocouple have?
A proper pilot flame should be blue with a yellow tip and should be strong enough to cover about 1/2 inch at the end of the thermocouple tip. If the flame is too strong and improperly adjusted, it will be blue but may be noisy and lift off the thermocouple, causing improper furnace operation.
How does a thermocouple prove a flame?
A thermocouple is a safety device that’s used to detect whether or not your furnace’s pilot light is lit. It contains a metal rod that is placed very close to your pilot light’s flame. When your pilot light is lit, the heat from the flame sends a voltage through the thermocouple that keeps the gas line open.
How does a gas flame pilot thermocouple work?
Most gas fire pilot or thermocouple controls are designed to “fail safe” – that is, the thermocouple keeps the gas valve open ONLY when it is sensing the heat from an adequate gas flame. The system operates on a system that generally doesn’t require an external electrical power source.
Where is the thermocouple located on a gas furnace?
Typically the thermocouple sensor is mounted right in the flame of the pilot light on gas fired heating equipment. Our photo (left) shows how you may spot the copper tubing of the thermocouple extending between its sensor at the pilot flame of a gas burning furnace and its connection to the gas control valve. [Click to enlarge]
How to replace a gas flame thermocouple in a water heater?
1 Turn off the gas supply to the equipment. 2 Remove access covers as needed: on a gas fired water heater you will need to remove the manifold door at the heater bottom in order to access the end of 3 Remove the old thermocouple at the gas valve by unscrewing its mounting bolt from the gas valve.
How big should the thermocouple be for a gas flame sensor?
To make necessary bends to route the thermocouple into position between the pilot-sensing end and its screw-in connection to the gas valve, use the bending template in the installation instructions. If you don’t have bending instructions, use a round object 2-3″ in diameter and keep bends gentle, avoiding crimping or squashing the tubing.
Why is the thermocouple not located in the flame?
Or your thermocouple sensor is not properly located within the flame. Also check that the other end of the thermocouple tube is fully screwed in to the gas valve. I put in a new thermocouple because when the pilot was lit and I turned it went out.
How does a thermocouple work on a gas furnace?
The top of the thermocouple is positioned in the flame, keeping the tip heated at all times. If the pilot flame goes out, the tip cools and the thermocouple automatically shuts off the furnace’s gas valve.
Can you use a 30 volt thermocouple on a gas flame?
I 30 millivolt thermocouple is pretty much the current industry standard and should be fine. Can you use a 30 volt thermocouple when it calls for 24 volt thermocouple? Lowering flame and “going out” could be an oxygen depletion sensor thinks the system is unsafe. Or your thermocouple sensor is not properly located within the flame.
