Gas Fireplace Not Working? Troubleshooting Steps to Try Before You Call

It's the first cold night of the year in Virginia. You flip the switch, and nothing happens. This is a common situation when people are trying to heat their homes when that first cold snap rolls through.

Why is my gas fireplace not working now? What do you do? Is it something you can handle by yourself, or do you need to call in the pros for gas fireplace troubleshooting?

The truth is that there are definitely some fixes that you can make on your own. But others are way too dangerous. We’ll break these down throughout the article. There is also a lot of bad advice out there on the internet, so that’s why we got our Colonial Plumbing & Heating HVAC experts together for some real information that you can trust.

Let's start with the easy stuff.

Start Here: The Five-Minute Checks

Work through these in order before you call anybody. We'd genuinely rather you find the problem yourself than pay us to come out and flip a switch. However, we want to make one thing clear, if you smell gas, stop. Do not keep flipping switches, relighting the pilot, or troubleshooting the fireplace. If you smell gas, follow your gas supplier’s emergency instructions. Get everyone out of the house. Don't try to locate the leak, and don't wait to get a technician scheduled.

Is the gas on?

There's a shutoff valve on the gas line feeding the fireplace. When you look, check within a few feet of the unit. Once you find it, look at the handle. If it is parallel to the pipe, the gas line is open. If it is perpendicular, the gas line is closed.

If you're on propane, check the tank.

Propane comes from a tank in your yard. Check the gauge. And if you have a grill or another appliance on that same tank, see whether it fires up. If nothing on the tank works, your problem isn't the fireplace. You just need to call for a propane refill.

Has the breaker tripped?

Not every gas fireplace needs electricity, but many do. Check your panel for a tripped breaker.

Is the wall switch on?

Make sure you're using the fireplace switch rather than a light switch on the same plate. Our Colonial Plumbing & Heating HVAC techs come across this situation all of the time out in the field. It’s especially common in people who just moved into a new house and are still getting used to the electrical configurations.

Check the batteries.

Everybody thinks of the remote. That’s the batteries they change, but still nothing works. But we bet you didn’t know that most gas fireplaces have a second set of batteries in the receiver module.

You can usually find this behind the lower louver or access panel.

If you've already changed the remote batteries and nothing improved, try this step.

Is the pilot lit?

Look through the glass or open the lower panel and see whether there's a small flame burning near the burner. If there isn't, that’s your answer. To relight it, refer to the unit’s owner’s manual. Give that a shot once, but if it doesn’t relight, the problem is bigger, and you’ll need some professional gas fireplace troubleshooting help.

If One of Those Fixed It, You Probably Didn’t Need Us

And that is fine. We would rather have you replace four batteries or discover an empty propane tank than pay for a technician to come and tell you the same thing.

But if you have made it through all five checks and the gas fireplace is still not working, keep reading because we still have plenty of tips.

What's Going Wrong: What Our HVAC Techs See in the Field on Gas Fireplace Not Working Calls

If the five-minute checks didn't fix it, the problem is inside the unit. Here are the internal issues our Colonial Plumbing & Heating HVAC techs see most often when out in the field on maintenance and repair calls:

The thermocouple

The thermocouple is a small metal probe is located in the pilot flame. The heat creates a small electrical current.

The thermocouple's job is to prove the pilot is burning. As long as it's producing enough current, the gas valve stays open. That signal tells the gas valve, in effect, “There is a flame here. It is safe to keep the pilot gas flowing.”

If that flame goes out, the current drops, the valve closes, and gas stops flowing. It’s a safety device, and when it malfunctions, the entire gas furnace goes off.

Because the thermocouple is in contact with the flame, it eventually corrode.

The pilot won't light

When we get a call about a pilot that won’t light, the first thing we look for is a blocked pilot orifice. That opening is tiny, and over a summer of sitting idle, it collects dust, pet hair, and spider webs. Spiders like the smell of gas and build nests right in the tube.

If you see a spark when trying to light the pilot, you can immediately rule out the igniter.

The main burner won't come on

This points to the thermopile. There's enough current to hold the pilot open but not enough to drive the main valve.

The flame is small and yellow

A healthy gas flame burns mostly blue and steady. If the flame is yellow, it means the air-to-gas mixture is off. This is the type of incomplete combustion that creates carbon monoxide. So, if you see a yellow flame, turn everything off and call us right away.

Here’s the big caveat…in this case, we are talking about the pilot light. A yellow main flame is not automatically a problem. In fact, many gas fireplaces are designed to look like wood burning fireplaces. Many properly operating decorative burners intentionally produce yellow and orange in the main flame.

It runs for a while, then shuts itself off

Something is telling the unit to stop. When we asked our HVAC techs the most common reasons for this, they told us:

• A failing thermopile
• A safety sensor
• An overheat limit tripping

A fireplace that fails immediately may send us down a different diagnostic path from one that operates normally until everything heats up and then drops out. Heat-sensitive components, pilot stability, controls, venting, fuel supply, thermostat operation, or model-specific safety systems can all enter the picture.

The burner lights unevenly

This is the symptom behind a huge number of “gas fireplace switch not working” searches.

This one usually comes down to blocked burner ports. It can also happen if the logs have been moved out of position — they're placed where the manufacturer put them for a reason.

Visible soot build up

On a gas unit, you shouldn’t see soot. Soot means the fuel isn't burning completely. According to our HVAC techs, this is often due to:

• Bad mixture
• Gas pressure issues
• Misplaced logs
• Restricted venting.

Soot is something you should not ignore. Something is causing it. We can help with gas fireplace troubleshooting.

Before you buy a thermocouple because somebody on the internet said “thermocouple,” find out what fireplace you own.

We are going to show you how to do that in a following section.

When the Switch or Remote Is the Problem

We wanted to give this its own section because it is something we see so often. You flip the switch, nothing happens, and there's no way to tell if it is a remote or a receiver problem.

Like we said earlier, first change both sets of batteries.

If that doesn’t work, it’s time to look at the receiver. A failed receiver is actually quite common. Most systems have a manual override — often a small switch on the receiver labeled something like ON, OFF, and REMOTE. If flipping that to ON fires the fireplace up, you've found the issue. In this case, the fix is replacing the receiver.

If the receiver is not the answer, it’s time to take a look at the wall switch.

It’s important to know that a gas fireplace wall switch isn't a normal light switch. It's carrying that millivolt current we talked about earlier and it has to be rated for it. The small current allows the wire to oxidize more quickly. And when too much oxidization builds up, the electrical signal stops.

For certain fireplace systems, a standard single-pole switch is perfectly acceptable when installed exactly as the manufacturer specifies.

What you absolutely should not do is assume the fireplace switch is a normal 120-volt lighting circuit and start applying household voltage to wires that may belong to a low-voltage control system.

Thinking About Installing a Smart Switch? Read This First

This is another place homeowners get into trouble.

A smart light switch designed for your living-room lights is not always compatible with a gas fireplace.

Many smart switches expect 120-volt household power and a neutral conductor. A fireplace control circuit may instead require an isolated dry contact that simply opens and closes the manufacturer's control circuit without sending external voltage into it.

Putting the wrong control on the wrong fireplace can damage equipment or create an unsafe installation.

If you want app control, timers, or smart-home integration, identify the exact fireplace and use a control system approved or compatible with that model.

What If the Switch “Works Sometimes”

A gas fireplace that works after flipping the switch three times, is telling you something. The main thing is to find out exactly what it is telling you.

One thing we often come across on service calls for gas fireplaces is resistance due to an aging switch or connection. If you are experiencing switch issues, they are not going to get better. In fact, they will get worse until the point that the switch stops working completely.

If your gas fireplace switch is not working consistently, give us a call and tell us exactly what it does. That will point our HVAC technicians in the right direction.

Just Moved In? Read This Section if Your Gas Fireplace Is Not Working

This is another popular phone call we get right after someone moves into a new home in the Tri-Cities area.

You bought a new house and it has a gas fireplace. The previous owners either never used it or used it once years ago, and nobody can tell you anything about it. There's no manual in the drawer and no service records.

With a unit that's been dormant for a decade, the biggest issue is that the system hasn’t been verified or inspected for a long time.

If the fireplace has been unused because it stopped working — which is often the story in these new home situations — then there's an existing issue that needs to be figured out.

Even if your gas fireplace is working, we don’t recommend trying to turn it on until after a professional inspection. Venting may be blocked or may have been compromised during a roof job. Furthermore, on a unit that old, some components may simply be past their service life.

The inspection also gives our HVAC techs a chance to figure out the make and model and give it the all clear that it is safe to run.

Rating Plate & Gas Fireplace Serial Number Lookup

Before giving us a call, you can learn a lot more if you can find the rating plate and gas fireplace serial number. First thing, take some pictures.

Get a clear photo of:

• The entire fireplace
• The controls underneath or beside it
• The remote, wall control, or switches
• Any visible manufacturer information
• The rating plate

The rating plate contains the model and serial number. On many gas fireplaces and inserts, it is located in or near the controls area behind the lower decorative panel.

Those numbers can tell you a lot.

A gas fireplace serial number lookup can help identify the exact model, locate the correct owner's manual, determine which ignition system it uses, find model-specific operating instructions, and help a technician research replacement parts or manufacturer information.

Do not assume a YouTube video for a fireplace that “looks just like yours” applies to your unit.

This Is Where DIY Gas Fireplace Troubleshooting Stops

Everything up to this point has been checks you can make yourself if you have a little bit of DIY savvy. But we have now reached the line where only professionals should handle it.

Anything inside the gas train is licensed work in Virginia. That includes anything to do with the:

• Thermocouple
• Thermopile
• Gas valve
• Burner
• Orifices
• Gas line and its connections

You'll find plenty of videos online showing things that only professionals should be doing. Don’t use them because you are risking your family’s safety.

What to Have Ready When You Call When Your Gas Fireplace Is Not Working

Gas fireplace parts aren't universal, and when you don’t know your make and model, parts procurement becomes difficult. Even within a single brand, the components change across model years.

So, when you call, the first thing we will want to know is your model and serial number. With it, we can get the right part out on the truck and the whole thing is done in one visit.

Where the rating plate is

Every gas fireplace has a metal or foil plate with the manufacturer, model number, serial number, and fuel type printed on it. It's deliberately placed somewhere it won't be seen from the living room.

We mentioned this briefly above, but this section explains how to find everything in detail.

Start with the lower louver or access panel. This is the grille or panel below the glass. The plate is usually mounted just inside on the frame or firebox wall.

If it isn't there, check the control compartment. That's usually behind the same lower panel. The rating plate could also be on the:

• Bracket
• Underside of the firebox
• Inside face of the frame

Some manufacturers put it on the side wall inside the firebox, visible once the logs are out.

Bring a flashlight and take a photo of the whole plate to refer to. Do not remove the rating plate from the fireplace.

Don't tear the fireplace apart hunting for it. Plenty of people can't locate the plate, particularly on older units or ones with an unusual layout. That’s not a problem! Our local HVAC technicians will help.

The fuel type

We’ll ask what fuel you’re using. In Central Virginia, that usually means either natural gas from the street or propane from a tank.

Why the Model Number Helps

The exact model can tell us:

• Which ignition system the fireplace uses
• Whether it has a thermocouple, thermopile, electronic flame sensor, or another setup
• Which remote or receiver belongs with it
• The proper log or media arrangement
• The manufacturer's troubleshooting procedure
• Which gas valve, pilot assembly, or control module, are compatible
• Whether those parts are still available for an older fireplace

That is why a gas fireplace serial number lookup is so helpful. It gives our HVAC technicians a start and speeds up the process.

Who Works on Gas Fireplaces?

For this question, a Google search often creates more confusion. You’ll see a mix of chimney companies, gas utilities, gas fireplace installation companies, and HVAC companies.

Who do you actually call when your gas fireplace is not working?

Here's the best way to think about it.

Your gas fireplace is a gas appliance. That is the same family of components as your furnace and your water heater.

So, the work you need is licensed gas work.

That's our trade. Colonial’s local HVAC techs have been doing licensed gas and heating work in Central Virginia since 1982, and gas appliances are what our technicians are in front of every day.

If you've worked through this list and your fireplace still won't run, that's what we're here for. Learn more about our gas fireplace repair and service, or call us at (804) 526-8415.

Test Your Gas Fireplace Before the Cold Weather Hits

Now is the time to test your gas fireplace.

Go flip the switch right now. Not in December — now, while it's still warm and you don't need it.

Because here's what happens every year. The first cold night arrives, and thousands of people go to turn on their fireplace that hasn’t been used since last March. A lot of them will find out that they need to have their fireplace repaired or serviced before it will work again. When you are trying to heat your home, that is a bad time to find out your gas fireplace is not working.

And all of those people start calling us the same week.

Testing it in September or October costs you nothing, and if you do need gas fireplace repair or service, you won’t have to wait for scheduling. We can usually get one of our local HVAC techs over to your home on the next day.

Ask us about a service agreement, or call (804) 526-8415 and we'll get you on the schedule.