The most common reason why a pilot light would start to burn yellow is that the air intake valve to the pilot light is clogged with dirt. If there is a small amount of dirt blocking the air, the yellow color might only be at the tip of the flame. If there is a large amount of dirt, the entire flame will burn yellow..
Besides, is a yellow pilot light dangerous?
It could be dangerous. But if your pilot light is yellow, or even if has a slight yellow or orange tint, then wasted energy may be the least of your concerns. A yellow or orange pilot light will produce carbon monoxide – an odourless, colourless gas that can fill your home and cause carbon monoxide poisoning.
Likewise, how do you know if you have a bad thermocouple? 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.
Also question is, what color should a gas pilot light be?
blue
Can a pilot light flame be adjusted?
Adjusting the Pilot Flame If the pilot flame is too small, you may be able to make it larger by turning the pilot adjustment screw on the valve control counterclockwise with a screwdriver to open it. The cause of a weak flame may also be an obstruction in the pilot tube.
Related Question Answers
What does a thermocouple look like?
The thermocouple looks like a piece of metal tubing smaller than a soda straw. To find it, first locate the gas control box. This is the box that the main gas line enters, where you turn the gas on in the furnace. The other end of the thermocouple sits in the flame of the pilot light.Can you test a thermocouple?
MultiMeter Thermocouple Test Procedure First, remove the thermocouple. Secondly, turn on the meter and set it to Ohms. Touch the two leads together from the meter, and you should get a reading close to zero. With the leads apart, you will read infinity.Can you clean a thermocouple?
If the Thermocouple is faulty it will cause the unit to shut down. How to clean? Remove Thermocouple from pilot assembly, using steel wool or emery cloth to lightly clean the tip removing any soot or build up that might have accorded due to an improper pilot flame.Can you get carbon monoxide poisoning from a pilot light?
Well, with one exception. Older gas ranges have standing pilot lights under the top cover that burn 24 hours a day, 365 days a year. And a pilot light out of adjustment can produce carbon monoxide gas. The amount produced by even a badly maladjusted pilot is small because the flame size is also small.What does the yellow flame indicate?
FLAME INDICATES EFFICIENCY A wavering, yellow flame on a normal gas burner indicates that the burner is out of adjustment or the air inlet is restricted. As a result, the burner may be producing excessive amounts of CO. However, the flames in burners that use fuel oil should burn with a clear yellow or orange flame .Can a thermocouple work intermittently?
a safety device that has started to go bad, or has failed permanently. In this client's case, the thermocouple was initially working intermittently, and then finally failed. This allowed the gas to flow long enough to heat up the thermocouple and generate some electrical current flowing back to the gas valve.What condition is usually the cause of yellow tipped flames in a gas heating unit?
The most common reason why a pilot light would start to burn yellow is that the air intake valve to the pilot light is clogged with dirt. When this happens, air will be blocked to the flame and it will suffer from incomplete combustion (causing the yellow color).How do I check my pilot light?
The pilot gas line is a small metal tube below the burner assembly and distinctive by the slight upturn at the end. It will be apparent, if the pilot is lit, by the small blue flame burning at the end. If you do not see a small blue flame burning, the pilot light is out.Why does my pilot light go out when I release the pilot light knob?
The most likely of those is that the thermocouple needs to be replaced. The button you press to light the pilot bypasses the thermocouple. When you release the button, the thermocouple ensures that unburned gas doesn't get released by shutting off the gas when it's not heated by the burning pilot light.Should the pilot light always be on in a gas water heater?
Your water heater does not have an ignitor. The pilot should always be burning on your water heater. Sometimes the pilot flame is hard to see through the viewing window. To be sure if the pilot is on or off, you need to remove the access door and shield and look at the burner and pilot through the opening.Is my pilot light too high?
A: There is a way to control the height of the pilot light 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.Is it dangerous to leave a pilot light on?
Reasons to leave your pilot on: When you turn off your pilot light, the light's tubes will maintain a trace level of mercaptan, and that will attract spiders, who will spin webs that can clog the pilot light system. But remember: running a pilot light all summer might cost you more than a decent sweater.Why does my pilot light keep blowing out?
If your furnace pilot light keeps going out, it's likely you have a broken thermocouple in your gas furnace. The thermocouple is a rod that comes into physical contact with the flame in your system. When this component is not able to detect the flame, it will close the gas valve to prevent a gas leak in your home.How do you test a thermocouple on a water heater?
If the pilot light doesn't stay lit, check the gas water heater thermocouple by keeping the pilot button depressed. Measure the current by using the multimeter device, set on millivolts. One probe of the meter should be connected to the copper sheath of the thermocouple and the other to the gas valve.Are all thermocouples the same?
From an operational perspective the thermocouples for a water heater are all pretty much the same. However, there are two variables, the length and the fittings used to install them, see below. A failing thermocouple will not send the correct electrical impulse and the gas valve will not release any gas.Why is pilot flame orange?
If your pilot light's flame is orange or yellow, it is burning inefficiently due to a lack of oxygen. The thermocouple should sense when this happens because the heat from the flame will not be as hot as it should be.How long will a thermocouple last?
Thermocouples can last several years, but they don't typically last as long as the furnace itself. If the pilot remains lit, but the main furnace doesn't stay lit, it's time to replace the thermocouple.What causes a thermocouple to fail?
Changes in temperature can cause regular expansion and contraction in metal, which will cause thermocouples to weaken over time. After enough time, metal fatigue can cause a thermocouple to break. If thermocouples start to give out unusual readings, it may be suffering from metal fatigue.Can a thermocouple be bypassed?
Bypassing the thermocouple would make it no more dangerous than any propane grill. It's not going to make it explode. The only thing it would prevent is losing a tank of propane into the atmosphere if the flame happened to go out because the valve wouldnt close. 
