Troubleshooting guide
Pilot is lit, but the main burner won't come on
Good news first: if the pilot is lit and stays lit, gas is reaching the fireplace. The problem is usually the signal that tells the main valve to open.
Check these first
- Valve knob on ON, not PILOT. Standing-pilot valves have OFF / PILOT / ON. Valor's guide also lists an ON/MAN dial that must be set to ON.
- Wall switch, remote or thermostat. Make sure the one you're using is actually calling for heat. On some systems the wall switch overrides the remote.
- Batteries in the remote and receiver.
- Thermostat setting, if you have one: set it above room temperature.
The usual culprit on millivolt fireplaces: the thermopile
On standing-pilot fireplaces with a wall switch or remote, a thermopile in the pilot flame powers the main valve. If it's weak, or the flame isn't hitting it well, the pilot burns happily but there isn't enough power to open the main burner. Manufacturer service documents (Empire's, for example) list this, along with switch wiring and the valve itself.
A tech can test it with a millivolt meter. Empire's service manual says a minimum of about 325 mV open-circuit is generally acceptable for its thermopiles. Exact numbers vary by brand and valve, so always use your manual's figure.
Electronic ignition: pilot lights, burner doesn't, then it shuts down
On electronic-ignition systems, if the pilot lights but the module can't sense the flame, it keeps sparking and then locks out. Heat & Glo's IntelliFire Touch guide calls this a 3 red / 1 green lockout. See IntelliFire error codes. Causes include a dirty flame sensor, a loose sensor wire or a poor ground, which are tech-level checks.
Common questions
Why is my pilot light on but my fireplace won't turn on?
Check that the valve knob is on ON (not PILOT), that the wall switch, remote or thermostat is calling for heat, and that the batteries are fresh. If all of that is fine on a millivolt fireplace, the thermopile may not be producing enough power to open the main valve.
What does a thermopile do in a gas fireplace?
It's a group of thermocouples wired together that sits in the pilot flame and generates enough voltage (hundreds of millivolts) to open the main gas valve when a wall switch or remote calls for heat.
Related guides
Thermocouple vs. thermopile
Two small parts that cause a lot of no-heat calls, and how techs test them.
Read the guideRemote not working
Batteries, switch position, then re-pairing. Steps from the manufacturers.
Read the guidePilot lights, then goes out
It lights, but won't stay lit. Usually the flame isn't heating the sensor enough.
Read the guideHeat & Glo IntelliFire blink codes
What 3 red / 1 green and other light patterns mean on IntelliFire controls.
Read the guideSources
- Empire Comfort Systems service manual: thermocouples, thermopiles and millivolt testing
- Valor (Miles Industries) Troubleshooting Handbook, Oct 2025 (GV60 control system)
- Hearth & Home Technologies, Field Service Guide for IFT (IntelliFire Touch) Control System, 2326-960 Rev H
Brand names belong to their owners. Fireplace Helpline isn't affiliated with or endorsed by any manufacturer. Steps and codes vary by model and year, so always check your own owner's manual.