Why is my pilot light not staying lit on my furnace?

Herein, should pilot light always be lit on furnace?

If you have an older gas furnace, your heating unit relies on a little blue flame known as a pilot light to ensure ignition of the burners. Water heaters, gas fireplaces and old gas stoves also often have similar pilot lights. Since the pilot light needs to remain active, your furnace is always consuming some gas.

Similarly, how do you clean a thermocouple on a furnace? Use a screwdriver to loosen the screws and remove the thermocouple from the pilot assembly for cleaning. Use a piece of steel wool or the abrasive side of a sponge to gently remove the soot without damaging thermocouple. Avoid using cleaning products, especially those containing flammable chemicals.

Correspondingly, how do I know if my thermocouple is bad on my furnace?

If you can't get the flame to light at all, and you're sure the gas is on, there's probably an obstruction in the pilot tube. If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds, that's the sign of a thermocouple malfunction.

How much does it cost to replace a thermocouple on a furnace?

Cost to Replace a Thermocouple on a Furnace Replacing a thermocouple costs $150 to $250, mostly due to labor time. On older models without an ignitor, it checks to make sure your pilot light is lit. If it's not, it'll shut the gas off.