Gas Fireplace Not Lighting?

If your gas fireplace is not lighting, you are not alone—this is one of the most common service calls during cooler weeks in Florida. The tricky part is that the symptoms (clicking but no flame, pilot won’t stay lit, fireplace turns on then shuts off) can point to several different issues, ranging from a simple cleaning need to a failing safety component.

This guide explains the most common causes, what you can safely check at home, what you should not do, and how to get reliable, safe heat back—without guessing.

If you’re in Tampa Bay and want a professional diagnosis and repair, Swept Away Inc. can help. Call 727-596-5946 or book online at https://www.sweptawaychimney.com/.

Why your gas fireplace won’t light (the big picture)

Gas fireplaces are designed with multiple safety checks. If any one of them fails—weak sensor, dirty pilot, low power to the valve, poor airflow, blocked burner ports—the system can refuse to light or shut itself down quickly. That’s a good thing: it prevents unsafe ignition and incomplete combustion.

Most “won’t light” problems come down to one of these categories:

Fuel: gas supply issues, shutoff valves, or utility interruption

Ignition: igniter, pilot assembly, electrode, or ignition module problems

Safety sensors: thermocouple/thermopile (millivolt systems), flame sensor (IPI systems)

Airflow/venting: vent restrictions or pressure-related shutdowns

Maintenance: burner ports clogged, dusty pilot, spider webs, lint, pet hair

Controls: remote, wall switch, thermostat, batteries, or control board failure

Safety first: what to do if you smell gas

Before you troubleshoot anything, use this rule:

If you smell gas strongly

Stop trying to light the fireplace

Turn the fireplace off

If safe to do so, shut off the gas supply to the appliance

Ventilate the area

Contact your gas utility provider or a qualified technician

A faint “first-use” odor can be normal when dust burns off, but a persistent gas smell—especially with repeated ignition attempts—should be treated seriously.

Common symptoms and what they usually mean

Clicking but no flame

Most often:

weak igniter spark location

dirty pilot assembly or burner ports

low gas pressure / shutoff valve partially closed

ignition module not opening the gas valve

Pilot lights but won’t stay lit

Most often:

failing thermocouple (older systems)

weak thermopile output (millivolt systems)

dirty pilot flame not properly engulfing the sensor

drafting/airflow interference affecting the flame

Fireplace lights, then shuts off after a few seconds or minutes

Most often:

flame rectification/flame sensor issue (IPI)

weak thermopile output (millivolt)

overheating safety switch tripping

venting/airflow problem causing flame instability

No response at all (no clicking, no attempt)

Most often:

dead remote batteries / wall switch issue

tripped breaker (for systems that use household power)

control module or board issue

gas valve shut off

What you can safely check at home (no tools, no disassembly)

These steps are safe for most homeowners and can resolve a surprising number of “won’t light” calls.

Step 1: Confirm the basic controls

Check your wall switch / remote / thermostat

If you have a remote: replace batteries (even if it “kind of works”)

Verify the wall switch is on

If there’s a thermostat, confirm it’s calling for heat

Check the receiver and sync

Some fireplace remotes lose pairing after battery changes or long periods of non-use. If you have the manual, follow the re-sync steps.

Step 2: Confirm the gas supply is on

Look for the shutoff valve near the fireplace

Most shutoff valves are either:

a key valve on the wall/floor near the unit, or

a valve in the lower access compartment

As a general rule:

Parallel to the pipe = on

Perpendicular to the pipe = off

If you are unsure, do not force anything—call a technician.

Step 3: Check the breaker (if your system uses household power)

Many modern gas fireplaces use electricity for the ignition system, fan, lights, or controls. If the unit is dead:

verify the outlet has power

check the breaker if the circuit has tripped

Step 4: Make sure the glass/front is properly seated

Some units have safety switches that require the front/glass to be installed correctly. If the glass is slightly out of position, the unit may refuse to run.

Step 5: Stop cycling it repeatedly

If the fireplace clicks repeatedly without lighting:

you can flood the chamber with gas briefly and trigger a safety lockout

you can worsen a minor ignition issue into a service call

Try once or twice—then pause and call a professional.

What you should NOT do (common DIY mistakes)

Don’t “adjust” components inside the firebox

The pilot assembly, burner ports, and sensors are precision-aligned. Improper adjustment can create delayed ignition, poor combustion, or unsafe conditions.

Don’t use compressed air blindly

Blowing debris around can lodge dust into the pilot orifice, worsen ignition, or introduce debris into the gas valve area.

Don’t bypass safety switches

If a safety device is stopping ignition, it is doing its job.

The most common real causes we see (and why they happen)

Dirty pilot assembly and burner ports

Why it happens

Florida homes collect dust, pet hair, and fine debris. Add in spider webs (yes, really), and pilot flames can become weak or misdirected.

What it causes

clicking/no ignition

pilot won’t stay lit

delayed ignition “whoosh”

uneven flame pattern

The fix

A proper cleaning and inspection—done carefully, without altering critical alignment.

Weak thermopile or failing thermocouple (millivolt systems)

Why it happens

These components convert heat into a small electrical signal that keeps the gas valve open. Over time, output drops.

What it causes

pilot lights but won’t hold

fireplace starts then shuts down

intermittent operation (works one day, fails the next)

The fix

Testing millivolt output and replacing the failing component.

Flame sensing problems (IPI/electronic ignition systems)

Why it happens

Modern systems verify flame through a flame-sensing process. Dirty sensors, poor grounding, or control module issues can prevent the unit from proving flame.

What it causes

unit lights briefly then shuts down

intermittent shutdowns

repeated ignition attempts

The fix

Proper diagnostics (not guesswork), cleaning/repair, and module testing when needed.

Gas supply or pressure issues

Why it happens

Partially closed valves, regulator issues, or supply pressure problems can limit ignition.

What it causes

weak ignition

fireplace won’t light consistently

low flames or delayed ignition

The fix

Confirming supply, verifying proper valve position, and checking for pressure-related issues.

Venting and airflow issues

Why it happens

Direct-vent systems rely on a specific intake/exhaust balance. Obstructions, nest debris, or improper termination conditions can interrupt safe operation.

What it causes

shutdown after a short run

sooting (serious warning sign)

unstable flame patterns

The fix

Inspection of the venting system, termination, and safety checks.

When to call a professional (and what to expect)

Call a technician if:

you smell gas or suspect incomplete combustion

the unit repeatedly tries and fails to ignite

the pilot won’t stay lit

the fireplace lights and shuts off repeatedly

you see black soot, excessive condensation, or unusual flame behavior

What Swept Away Inc. does differently

When we service gas fireplaces, we focus on safe diagnostics, not quick guesses. We inspect, clean, and verify operation so the system starts reliably and runs safely.

You can book service here: https://www.sweptawaychimney.com/

And for inspection-related services and qualifications https://www.sweptawaychimney.com/inspections-and-qualifications/

Gas fireplace maintenance: how to prevent “won’t light” problems

Annual service is the simplest prevention

Even in Florida, gas fireplaces benefit from annual checkups because:

dust and lint accumulate inside the unit

burners and pilot assemblies clog

sensors and connections degrade

minor issues become intermittent “it works sometimes” problems

Keep the area clean

vacuum around the fireplace exterior (not inside the firebox)

keep pet beds and heavy lint sources away from the intake area

avoid storing items in the lower control compartment

FAQs: Gas fireplace not lighting

Why does my gas fireplace click but not light?

Usually ignition is attempting, but the pilot/burner is not receiving the correct fuel/air mix or the spark is not igniting the gas. Dirty pilot assemblies and weak ignition components are common causes.

Can I relight my pilot myself?

Some fireplaces are homeowner-relightable and some are not. If you have the manual and you’re comfortable following it exactly, you may be able to relight it. If it won’t stay lit, that is typically a sensor or pilot flame quality issue—call a pro.

Why does my fireplace turn on and then shut off?

That typically means the system is failing a safety verification (flame sensing/thermopile output/overheat or venting-related shutdown).

Is it dangerous to keep trying?

Repeated ignition attempts can trigger lockouts, worsen underlying ignition issues, and—if there is a venting or gas-supply problem—create unsafe conditions. Two attempts is plenty. After that, schedule service.

Service areas and booking

If you’re in the Tampa Bay area (Tampa, Hillsborough, Pinellas, St. Petersburg, Clearwater, and surrounding areas) and your gas fireplace won’t light, schedule a diagnostic service with Swept Away Inc.

Book online: https://www.sweptawaychimney.com/

Call: 727-596-5946

BOOK NOW