What Causes a Furnace Pilot Light to Keep Going Out?

South End Plumbing, Heating, & Air Expert Tips

What Causes a Furnace Pilot Light to Keep Going Out?

What Causes a Furnace Pilot Light to Keep Going Out?

You awake on a cold winter season morning and cast the covers aside. A fierce, freezing draft sends shivers down your spine. Something’s wrong. The heater quit working eventually during the night.

Efforts to re-light the pilot light are futile. It will not remain on. Perhaps the pilot remains on for a moment and the furnace tries to fire, however almost right away closes down. Why does this happen?

Prior to yielding the cost of emergency repairs and calling an a/c professional, read ahead for some of the most common reasons your heater pilot light will not remain on. You may be able to repair the problem on your own if you have actually got the tools and the know-how.

Obviously, if you wish to ensure the job is done right with the least quantity of risk, contact experienced experts at South End Heating & Air for furnace repairs as soon as possible.

1) Faulty Thermocouple
If your pilot light won’t stay lit, the thermocouple is highly likely the cause of the problem.

The thermocouple is the copper rod the pilot flame directly strikes. Sometimes it’s referred to as the “flame sensing unit.” It’s a safety mechanism that shuts the gas off should the pilot head out. If the thermocouple fails to turn off the gas, all the gas streaming through the heater might get into your home. The thermocouple safeguards against a devastating accumulation of gas.

Furnace Thermal Coupler
Furnace Thermal Coupler

Do it yourself Repair – How to Locate the Thermocouple

First off, grab a flashlight and a screwdriver before inspecting your heater. You’ll need to remove the cover, and opportunities are the lighting won’t be operating in your favor. The only thing more aggravating than a broken heating system is a hundred trips to the garage for tools when you’re attempting to repair it.

For safety’s sake, turned off the power to the furnace by switching the breaker to the off position, and closing the gas valve.

The thermocouple isn’t too difficult to find. Find the pilot burner and look for the end of a copper rod extremely nearby. That’s the thermocouple.

What if you can’t find the Pilot Light?

If you’re having difficulty finding the pilot or thermocouple, double-check to make sure your system really has a standing pilot light. Standing pilot burners are common in older heating systems, however, numerous newer heating systems have intermittent pilot lights or hot surface igniters. In these systems, the pilot will just light (when it comes to hot surface area igniters, the igniter surface area heats) when the thermostat makes a signal for heat.

No matter the pilot setup, the thermocouple will be near the burners– look for a removable metal rod nearby.

Why does the Thermocouple Stop working

The thermocouple is what detects the heat from the flame, otherwise, it will shut the gas valve, and your heater will not work properly. There are 3 reasons your thermocouple might be malfunctioning:

It’s Broken

A broken or stressed-out thermocouple will not detect the flame effectively, effectively closing the gas valve up until you change it. Replacing a damaged thermocouple is cheap and reasonably easy if you’re mechanically inclined. Contact professional heating system repair work specialists at South End Heating & Air for thermocouple repair work if you aren’t so confident. It will not cost you much.

It’s Not Lined Up

The pilot light flame needs to totally cover the top of the thermocouple rod so it understands the flame is on. If the thermocouple isn’t lined up properly, it will not read the flame and will shut the valve for the gas.

It’s Dirty

Soot buildup on the thermocouple may obstruct the flame. Under constant direct exposure to a hot flame, a thermocouple wears down gradually. Even a minor residue can make the thermocouple break down. The fix here is as easy as getting rid of the thermocouple, cleaning it with a wire brush or something coarse (even a piece of sandpaper works), and replacing it.

If removing and cleaning the thermocouple is something you’re comfortable doing, perform this routine maintenance yearly. This is do-it-yourself heating system maintenance you can carry out on your own to extend the life of your furnace and avoid emergency situation repairs.

If you try to fix or change the thermocouple on your own, remember to close the gas valve and turned off power to the heater by turning the breaker first to prevent a mishap.

2) Pilot flame opening is Dirty

If you can manage to get the pilot burner lit for just a moment, check the flame. The pilot light is expected to be a strong blue cone, not a weak yellow flame. A weaker flame won’t envelop the thermocouple effectively. The pilot orifice may be full of dirt. Cleaning out the pilot orifice suggests dismantling the pilot and cleaning out the debris utilizing a needle or compressed air. If you’re not excited to begin tampering with crucial parts of your heater system, heater repair professionals at South End are simply one telephone call away to help you out.

3) Bad Gas Regulator

A bad regulator in your natural gas meter outside your home will affect all of the gas appliances in your home, including your heating system, clothes dryer, range, etc. Your furnace might not be getting enough gas to keep the pilot lit. If you notice pilot problems in several of your family appliances, this may be the perpetrator. Contact your energy business right away.

4) Fluctuating Gas Amount Based on Need

There could be absolutely nothing wrong on your end. When gas usage peaks, the “gas grid” in your area might be nearing its capacity and lower the gas pressure intermittently. Even the tiniest hiccup in the gas supply to your heater could be enough for the pilot light to shut down. Ask around your neighborhood and find out if anybody else has actually had problems with their gas. Get in touch with your utility business if the problems continue.

5) Improper Air Circulation, or a Strong Draft, Blows the Pilot Out

If your pilot light re-lights easily after going out overnight, it’s possible it was burnt out by a draft. This can happen on exceedingly windy days or nights. A leakage in the output duct of the heater could trigger air to blow into the area. Keep every intake air register in your house open and clear to prevent a “vacuum” effect in the inlet.

Let South End Heating & Air Troubleshoot Your Problems

Diy maintenance and repairs can only fix a certain amount of simple solutions, unfortunately. If your heater is still malfunctioning after you’ve repaired or replaced the thermocouple and identified the flow of gas isn’t an issue, you’ll need the help of a skilled expert to find out what’s wrong with your heating system.

At South End Heating & Air we specialize in Furnace Repair and Replacement, contact us for a free consult. We’ll evaluate your system and help make recommendations for optimum value. After all, we want to keep you cool all summer long and warm in the winter. Just schedule a visit with one of our technicians to talk about how we can help with your thermostat settings. Would you like to learn more options our techs can help you with? give us a call 704-684-5339

Check out South End Plumbing for all of your plumbing needs.


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