Gas Fireplace Won't Light but the Pilot Is On
Short answer. When the pilot is lit but the burner will not come on, the fault is almost always in one of four places: the wall switch, remote or their batteries; a weak or dirty pilot flame; the thermopile or thermocouple next to the pilot; or the gas valve and its control module. The first one you can check yourself in five minutes. The other three need a technician, and our diagnostic visit is free: you get the price of the repair before any work starts.
Key facts
- Diagnostic visit
- free
- Brands
- any brand of gas fireplace
- Service
- once a year, before fall
Prices from our published price list, valid through December 31, 2026. Your quote is itemized after a free in-home assessment.
I am Eric. I repair gas fireplaces next to furnaces and heat pumps, and this is how I work through "the pilot is on but it will not light". We repair any brand of gas fireplace.
First, safety
- If you smell gas, do not try to light anything and do not flip switches. Leave the house and call your gas utility from outside.
- Follow the lighting instructions on your fireplace. They are printed on a label or plate, usually behind the lower grille. Every model lights a little differently.
- The glass gets very hot and stays hot long after the flame is off. Keep children and pets away from it.
- A carbon monoxide alarm near the fireplace room is worth having in any home with gas appliances.
How a gas fireplace lights, in plain words
The pilot is a small, steady flame. Sitting in that flame is a sensor: a thermocouple on older or simpler fireplaces, a thermopile on most fireplaces with a wall switch or remote. Heated by the pilot, it makes a tiny electric current. That current tells the gas valve it is safe to open, and, on most fireplaces, also powers the switch circuit. When you flip the switch or press the remote, the valve opens and the main burner lights from the pilot.
So "pilot on, burner off" means the pilot is fine, but the signal or the gas is not getting from the pilot to the burner.
Check 1: the switch, the remote and the batteries
This is the part you can do yourself, and it solves a fair share of calls.
- Wall switch: make sure it is on. If someone turned it off at the start of the season, the remote alone will not light the fireplace on many models.
- Remote: replace the batteries.
- Receiver: many remote systems have a receiver with its own batteries, often in the control compartment behind the lower grille. Replace those too, and check whether the receiver has its own switch set to ON or REMOTE.
- Try again with the remote and with the wall switch.
If the fireplace now lights, you are done. If not, the problem is one of the next three.
Check 2: look at the pilot flame
Without touching anything, look at the pilot through the glass or with the grille off:
- Healthy: a strong, mostly blue flame that wraps around the tip of the sensor next to it.
- Weak: small, lazy or mostly yellow, barely touching the sensor.
A weak flame does not heat the thermopile or thermocouple enough, so the valve never gets the signal. Dust, spider webs and soot in the pilot assembly are the usual reason. Cleaning it is a technician's job: the pilot sits next to the gas valve and the sensor, and it has to be set back exactly right.
The four parts behind "pilot on, won't light"
From the fireplaces we repair, these are the causes we see most:
- Thermopile or thermocouple. These wear out. A tired thermopile can keep the pilot burning but no longer makes enough current to open the main valve. It is a routine repair.
- Dirty pilot or weak flame. As above: the sensor is in the flame, but the flame is not strong enough to do its job.
- Wall switch, remote or their wiring. Dead batteries in the receiver, a failed receiver, a worn wall switch or a loose wire in the switch circuit.
- Gas valve or control module. We test everything above first, so a valve or module is replaced only when it is really the cause.
"The pilot keeps going out"
A related call. If the pilot will not stay lit after you let go of the button, the usual causes are the same sensor (a thermocouple or thermopile that no longer holds the valve open) or a dirty pilot whose flame does not reach the sensor. Do not keep relighting it over and over. Turn the gas valve on the fireplace to OFF and book a visit.
"There is a small flame even when the fireplace is off"
That is usually just the standing pilot doing its job: on many fireplaces it stays lit through the season by design. If you see a larger flame on the burner itself while the fireplace is switched off, turn the gas valve on the fireplace to OFF and call us.
Before you call: details that save a trip
- Brand and model, from the label behind the lower grille. A phone photo of the label is perfect.
- What happens when you press the switch or remote: a click from the valve, nothing at all, or the burner lighting for a second and dropping out.
- How the pilot looks: strong and blue, or small and yellow.
- When it was last serviced, if you know.
It helps us bring the right part on the first visit.
What a fireplace visit costs
The diagnostic visit is free. We find the cause, tell you the price of the repair, and you decide. You pay only for the repair itself.
In one of the Google reviews on our site a homeowner wrote that Eric was able to "diagnose the problem within only a few minutes and restore functionality." We find the cause first, then fix it.
Once a year: the fireplace service
We recommend a service visit once a year, ideally before you start using the fireplace in the fall: cleaning the pilot assembly, checking the sensors and the switch circuit, and looking over the burner and the glass. A yearly visit catches a weak pilot or a tired sensor before the first cold evening. If you already book heating maintenance for your furnace or heat pump, ask us to look at the fireplace on the same visit.
Fireplace still dark?
Book a free diagnostic visit or call +1 (253) 553-9579.
FAQ
Can I clean the pilot myself?
We do not recommend it. The pilot assembly sits right next to the gas valve and the sensor, and it has to go back exactly where it was.
Why does my fireplace light from the switch but not from the remote?
Usually the remote or receiver batteries, or a receiver that has failed. Replace both sets of batteries first.
Is it safe to leave the pilot on all season?
On fireplaces designed with a standing pilot, yes; that is how they work. If you will not use the fireplace for months, you can turn the pilot off following the instructions on the label.
Do you service gas fireplaces, not only repair them?
Yes. We recommend a service visit once a year, before you start using the fireplace in the fall.
How fast can you come out?
We arrive at a time agreed in advance, often the same day once a time is set, and we are 30 to 60 minutes from any city we serve.
Related: Heating repair · Maintenance · Furnace not heating · Eric, HVAC technician
What changed: October 25, 2026: Published.
