Please visit the troubleshooting guide options or continue reading for a more in depth look at gas fireplaces and how they work.

Standing Pilot Units


Millivolt Gas Valve Issues

IPI and Electronic Ignition Fireplace Issues


Dirty Glass and Other Maintenance Issues

  1. Tamara and David Proctor

    In just fifteen minutes or less we fixed our gas fireplace. We spent $150 last year with a repair man trying to get it going again. The same repair man estimated it would take between $500 and 2500 to fix our fireplace. It was all in the switch!! Thanks you so much!!! Tamara

    • admin

      Awesome! Thank you for your comment. That’s great to hear. Please share this site with your friends!

  2. Russell

    I have a superior d-500cmn the pilot would not stay lit after releasing the button I have now replaced the thermocouple and I still have the same problem. What now? Thanks

  3. John Langen

    I have a direct vent heat n glo gas fireplace I purchased about 10 years ago. From new the the fireplace has stayed lit at times for days, months, hours and even minutes and then goes out, main burner and pilot together. I then relight the pilot and start burner again wondering how long this particular session will last. I have payed for countless service calls and all is good when they leave, but sure enough after a day month or even longer the same thing happens. At this point I,m ready to just buy another fireplace. This is rather a important fireplace as it keeps the master bed room warm in the winter and is hooked to a thermostat. Thank-you John

    • admin

      Does the flame change in appearance right before the fireplace goes out? What has been replaced so far? How is the unit vented?

      • John Langen

        As far as I can see the flame does not change in appearance before shutting off, The flame has a nice blue color with whispers of orange on the top of flame.The thermocouple and the main valve has been changed. The only thing left to change is the thermophile.The unit is vented vertically with one short 90 towards the back wall and then another 90 straight backup. This is to offset the vent back so at the time a old style TV could be placed further up the wall in front of the fireplace. The venting from the top of the Fireplace to the termination cap outside above the roof is approx 16ft. From what I can see the fireplace has a excellent updraft, to the point that it will slightly pull away the pilot flame from the thermos. However I have never had the pilot go out when the main burner is not fired.I’m now thinking to put a shield around the back of the pilot flame and thermos so that the flame is not pulled to towards the center of the fireplace.The model is 7000XLT-NF Natural Gas. Thank-you John

        • admin

          I would try a vent restrictor. It sounds like once the fireplace establishes a good draft, it pulls the pilot flame away from the thermocouple sensor. You can usually order a restrictor that goes in the vent pipe that slows down this draft.

          Otherwise a pilot shield might work also.

    • Keith

      I have the same problem with mine. It will stay good for an hour sometimes or 2 min other times. The pilot light then won’t light for an hour or so, then it starts all over. 2 service calls so far; the guy can’t figure it out.

      • admin

        When the phe pilot light won’t light for a hour or so, will it ignite and just not stay lit? Or does it not ignite at all? What is the make and model of the fireplace?

  4. Pat Higgins

    I have a gas fireplace that only lights when it wants to. It has no pilot light it has a wall switch . It says Heatilator on it .

    • admin

      This sounds like an IPI or electronic ignition fireplace. What is the model number?

  5. Scott

    Lots of great info here, thanks.
    Do you have any knowledge about “delayed ignition”?
    Is the cleaning that my local company suggests something I could do myself??

    • admin

      Delayed ignition can be caused by a poor pilot flame, plugged burner ports, or incorrect venting. If this is a relatively new issue, we can probably eliminate venting as a possible cause.

      Check your pilot flame. It should be directed over the main burner so that when the burner releases gas, it will ignite rather quickly.

      Sometimes burner ports can get plugged. Gas log sets with sand over the burner can have the sand melt and plug the burner ports over time. Otherwise spiders (they like the smell of the gas additives) can build nests inside burner orifices and burner tubes, slowing the release of gas to the burner.

  6. Nura

    THANK YOU. We’ve been avoiding having a repair man come look at our fireplace and just happened to stumble upon your website. 15 minutes later, our fireplace is working perfectly! It was just the switch and you’ve saved us time and money. Sincerely appreciate it!!

  7. Mary

    Our fireplace feels like the window is open. In the winter, we actually get frost on the hearth. We now have it covered in window plastic. It is about 10 years old and is a superior bri-36. The flue is closed. We are at a loss…Thanks..

    • admin

      Most of the time, cold air issues are related to how well the exterior wall behind the fireplace is insulated. When the fireplace is first installed, it gets framed in with 2×4 framing. The framing behind the fireplace should be insulated and have a vapor barrier on it. Many times, it may be insulated but not very well. Also, there should be a “ceiling” built above the fireplace that has insulation on the top of it. This is often called a firestop or draft-stop. The ways to check these things include either:

      1.) renting a snake camera and fish it behind the fireplace to see whats back there, or
      2.) taking the siding off behind the fireplace and cut a hole to look and see.

      I’m guessing this is the case.

  8. BJ

    I have a buzzing coming from my fireplace and it does not shut off all the time when I turn it off from the switch. Could this be from a bad thermopile sensor?

  9. Kathy Pfau

    How do you become a local certified technician on your site?

    • admin

      Local certified technicians listed on this site have been certified through the NFI (National Fireplace Institute). They have proven knowledge of fireplaces, log sets and stoves as well as their venting systems. An NFI certification is required to be listed on this site.

  10. Trey

    I have a SFC and not sure if a VF5-CMN-2, VF5-CMP-2, VF6-CMN-2, or a VF6-CMP-2 but all oare listed on the manual.

    The pilot light will stay running (only with the wall switch on) but the main burner will never light even pulling the logs and using a light a different spots on the burner assembly. I turn the low/high knob to several positions and wait and nothing ever happens. Only the pilot burns. Any suggestions?

  11. Ed Varney

    Fireplace lights easily when wall switch is turned on. Problem is that the flame pulsates when operating. Flame does not go out until wall switch is turned off.

    • admin

      Is this a standing pilot unit? Or electronic igniton? Whats the model number?

  12. Jon

    I have 2 Desa NG fireplaces model VM42B and VM36B. Both will not come on with wall switch. If you jump TH/TP to TH the start with the switch on. Thermopiles are 700-900. If you try to bypass the switch and connect wires together nothing untill you jump TH/TP with TH. Any suggestions? Thanks.

    • admin

      I would start at the TP/TH and TH terminals then follow the wall switch wires back to where they go through the fireplace and back to the wall switch. Make sure that either wire does not go to another sort of sensor, spill switch, or rocker switch somewhere before it goes to the wall switch. Its not uncommon for there to be a saftey sensor that breaks the connection if it senses the fireplace is overheating or venting into the room. Many times this sensor will malfunction.

      If not, it must be in the wall switch wire in your wall.

  13. Jon

    I checked the thermopiles fireplace 1 was 890 switch on 480. Fireplace 2 was 780 switch on 360.

  14. Phyllis Mack

    Just closed on a house. The area above the gas fireplace was kind of black, thought it might be a closed flue issue. Painter #1 says it is leaking and needs to be caulked with high heat caulking. Painter #2 thought it might need a new gasket. Shall I caulk it or call someone? Thanks.

    • admin

      This is a tricky one. It also could be a result of back puffing when opening the door too fast, or your house is very tightly insulated and there is an issue with sufficient draft up the chimney.

      You can check the gasket by using the “dollar bill test”. Take a dollar bill and close it in the door. When you try to pull it out you should feel some resistance. If it comes out without much effort, you may need to adjust the door or replace the gasket.

      If you want to be sure, I would hire a certified fireplace technician to do a thorough inspection of the fireplace.

  15. Charlene Morgan

    Just bought a house with a gas fireplace. The gas fireplace lights up using a light switch on the wall. When I flip the switch to turn the fireplace on it lights up okay, but when I turn it off there is a constant small flame coming from the line which supplies the gas in the firebox, is this normal?

    • admin

      Yes. This is called a pilot light. It will always stay lit even after you have turned your fireplace off

  16. Daniel R. Morgan

    The information that you have provided is very informative; however there is no information about the fan that blows the air out. The fan is control by an electrical switch, which is mounted on the wall, but when turn on nothing happens, if you can please advise or call me at (609)291-2789. Oh! by the way it use to work until the pilot light went out and we had to have it relit, we must have moved something or touch something that we should not have done.

    • admin

      Many times, the blower works off a temperature sensor and will not allow it to turn on without the fireplace heating up for a while.

      I would also check to make sure the fan is plugged in. When I do service on a fireplace I usually unplug the blower so I don’t accidentally shock myself. Flip open the lower grill/louvered area of the fireplace. On the very left or right side you should see an electrical outlet. Make sure the blower cord is plugged in.

      You can also check to see if there is a rheostat (speed control) knob underneath there as well. This could have been turned off or bumped so it is on a very low speed so you may not hear the blower running.

  17. Jeb

    I have a heat n glo sl-36gdv-cdn. My wall switch won’t work. My pilot stays on and if I switch it to on underneath it lights up and my wall switch won’t do anything. If. Turn it off underneath it turns off.

    I tested the thermopile and got 400mv on off and when I turned my wall switch no change and when I turned it on below I got like 175.

    Any idea what the problem can be?

    • admin

      Sounds like your wall switch is bad. Change it and it should work fine.

  18. Bill Haldaman

    Thankyou for this very informative site. I learned a great deal about gas control valves.

  19. AndyS

    I have a millivolt system that randomly turns the fireplace on and then off. Could this be the wall switch?

    • admin

      Most likely. Does it run on a wall mounted thermostat or is it just a switch?

  20. dixie

    Having trouble with my gas fireplace…
    Two years ago my boyfriend try to turn it on and did not work, the year after my brother and boyfriend try again and they were able to turn it on I did use it all winter… now this year it does not want to turn on… my boyfriend try even to use a lighter directly on the piloy but it looks like if there is no gas coming out… what should we do? Can you help please…

    • admin

      If you turn your pilot light off in the summer, you may have blockage inside your pilot tube (spiders like the sulfur smell of gas). You would have to clean out your pilot tube. But first start by making sure your gas supply is turned on or your propane tank is full and fully on.

      To check for blockage, I start by unscrewing the pilot tube from the main control valve. Then push in your pilot knob like you normally do to light the pilot. You should hear gas coming out of the side of the valve where the pilot tube was screwed in. This would confirm blockage in your pilot tube. Sometimes you can clean it out by blowing through it, but sometimes you have to take it apart and run a small wire down it to clean it out.

      This can be a little tricky and may be worth contacting a service technician if you do not feel comfortable.

  21. Fred Zietlow

    I have a Warnock Hersey direct Vented Gas Fireplace WH-6540 which has been working fine for years, however this Fall when I tried to start it I got the Pilot Light going and after 30 seconds warm up when I turned the control from Pilot position to ‘ON’ the main Burner comes on for a moment and slowly goes out again. I’ve cleaned everything up including the Burners but the problem repeats itself. Could this be a fault with the Thermocoupler ???????

  22. jae oneil

    I have a HeatnGlo SL-550TR, a basic system, that won’t shut off at the wall nor using the rocker switch in the located at the bottom of the unit. Only manually turning off the pilot/ignition dial will do it. Does this indicate that there is a short at the rocker switch?

  23. erica

    We just moved into a house that has a wood burning fireplace converted to gas, I can’t get it to light and I have no idea where to start

    • admin

      Start by diagnosing your pilot light. You may just need to light your pilot.

  24. Dustyn

    We have a Majestic SRT36 direct vent gas fireplace. Early this year, we lost the flame on the main burner. We had the Energy company come to the house and they recommended we change the thermopile. Being that the summer was near, we decided to wait.
    We replaced the thermopile with no luck, so we change the thermostat (replaced with a Honeywell). Unfortunately, the main burner still will not light. I have been trying to self diagnosis this myself and stumbled onto this site.
    Reading through this thread, we decided to purchase a multimeter. The reading with the thermostat off is 387 and when turning the thermostat on it was also 387(we played with the temperature – same reading regardless of temperature). The pilot stays lit so we likely don’t need to change the thermocouple. The pilot flame is blue with an orange glow on the top perimeter. Any ideas as to what could be the issue? I am determined to figure this out without having to call a tech. 🙂

    • admin

      It sounds like the thermostat or wiring for the thermostat is bad. Did you try jumping the valve with a piece of wire to see if it comes on that way?

  25. Luc Juteau

    Day 1
    Pilot light does not stay on, remove and clean component of the pilot system. Still not working.
    Remove copper tube that feeds the pilot system and discover some small piece of dirt/rust. Now pilot stay on flame large enough had to reduce the flame size with the pilot screw.
    First time in 2 years that the pilot flame is working. Yes I am happy.
    Repainted the inside of the gas fireplace. Looks good.

    Day 2
    New problem, the main burner does not come on.
    Pilot flame is burning.
    Thermopile output voltage is;
    540mv with the wall switch off / no load
    262mv with the wall switch on / loaded
    I can hear a picking noise when the wall switch goes on, I think the valve gets activated.
    Main burner is not on why?
    Also what are the two adjustments called in & out, these look like valves similar to the pilot light adjustment and they are closed. Was 2 years to long?

    OK I have learn a lot in the past few days on gas fireplace.
    I did a dumb thing I forgot to turn the knob from pilot to ON, now it works fine.

    The clicking sound is the relay engaging which is OK.
    The voltage are normal both loaded and unloaded.
    Still do not know what the in and out screws/valve are but they need to be fully close.

    I will get to bed a little smarter today.

  26. Lesley

    I have an IPI Heatilator fireplace. At the end of last winter it was working fine. Mi went to start it this year and flipped the switch on the wall. I heard the clicking and saw the pilot light come on but the burner did not light. I checked the pilot light for corrosion and cleaned it but still isn’t working. Any ideas?

    • admin

      An IPI system is a little different. Check the main control valve. There should be a green wire connected to a green terminal and an orange wire connected to the orange terminal. Make sure these did not come off the valve and are connected securely.

  27. Angela

    My fireplace hasn’t been working for 2 years. I was about to have it serviced/replaced when I found your website. In less than 20 min. my pilot was lit and my fire was burning. The video tutorial was extremely easy to follow.
    Thank you, thank you, thank you!

  28. Mike E

    Lot’s of great info. I have been having issues with my Majestic DVBR36, Millivolt Direct Vent natural gas system. Pilot lite seems to be ok. Issue arises upon starting. When I throw the switch, the fire will not spread from the pilot to the fireplace. Sometimes if I tap on the ignition unit (Honeywell VS8420E2012), the fireplace will light. However, within 20 mins to an hour, the fireplace goes out. I checked the gas flow to the ignition unit And it seems consistent. I assume that the issue is the ignition unit. If you agree, is there any maintenance that can be done to the ignition unit, or does it need to be replaced? Thank you.

    • admin

      Please follow the main burner issues troubleshooting section on the website. It could be a number of things. Start with the tutorial to help narrow it down.

  29. tim

    thanks for the site, changed my switch and now all works, but there is a smell when the fireplace is on, not really a burning or gas smell–didnt know if you had any thoughts. just moved in so unsure of any past problems–majestic ventless

    • admin

      Ventless fireplaces will always have an odor. It can be stronger if it hasn’t been used in a while (dust and other aldehides will burn off the burner and logs and create odor).

  30. JE

    I have a heat-n-glo SL-550tr-D that is about 10 years old. The pilot light stays lit, but after the main burner is on for an hour or so, it will go out, then in 15 seconds or so, come back on. I can also turn the wall switch off then on and it will light again. Any thoughts?

    • admin

      Please use the website tutorial on main burner issues. It seems like this is a classic case of “bad wall switch”

  31. dave

    I have change the thermocouple and the thermopile, the pilot light is on but the fireplace will not fire up.
    Please advise what the problem could be?

    • admin

      Is the thermopile fully engulfed by the pilot flame?

  32. Thomas Gomez

    HI I have a Mendota fv41 unit . It has both standing pilot and ipi modes. It was working fine, then started shutting off on its own. Now in either mode the spark ignitor keeps sparking after the pilot light is lit for 30 secs at which time both pilot and ignitor turn off. The system tries this two more times before shutting down. Pilot has hood and flame looks good but is not touching the thermocouple. Any ideas ? Thanks in advance.

    • admin

      IPI systems are different than standing pilot systems. With an IPI system, the pilot is sensed by a small wire-like rod (called a rectifier). Most likely this has some buildup on it and is not sensing the flame (which is why it continues to spark after the pilot is lit). Take a $1 bill (or emery cloth) and use it to rub off the rectifier and pilot hood (make sure its cool when you do this). After the rectifier has been cleaned it should sense the flame, stop sparking, and ignite the burner.

  33. Dan Russell

    Hi – great site with good information. We have a Heatilator with IPI. Last year the fireplace worked fine when we flipped the wall switch. This year we just hear a fast clicking sound when we flip the switch – there is no gas smell. The gas valve is turned on. I cannot see a spark being generated but it might be hidden by the logs. Any ideas where to start troubleshooting?

    • jamers423

      Hi Dan,

      Many times with IPI units, if the fireplace hasnt been used in a while, there may be air built up in the gas line. I would remove the glass assembly and shine a flashlight around inside to find the pilot assembly. It is usually located underneath the rear log in the middle. flip the switch and make sure you see a spark. If all your gas shutoffs are turned on, eventually it will light but it may take 10-15 tries to completely bleed out any air in the line.

  34. Scott

    Hello! This is a really great site.

    I’m trying to get my natural gas fireplace lit after having the pilot off for the summer. I fixed the first problem (pilot won’t lite) by removing the dust / dirt from around the pilot. The second problem (pilot wont stay lit) I fixed by lightly sanding the thermopile. Now, I have another problem!

    When I turn on the fireplace, a large portion of the flame appears on the left side, and no flame appears on the front / right side. The gas enters at the back (which burns ok), and goes around from left to front to right via a pipe with holes in it. There is one hole that seems particularly large on the left (approx 1/8″), and there is a disproportionate amount of flame coming out of it. I have tried tried using my shop vac to suck the smaller holes around the front of the pipe clean, but the problem persists.

    I wonder if I have not returned the fake logs properly, or if there is something else that is supposed to block the large hole on the left. I suspect that if this hole was blocked, the gas would make it to the front / right side of the pipe before it runs out of pressure…

    Any advise is appreciated

  35. jamers423

    Pull the ignitor wire off the module and hold it close by. Then turn it on. You should see it arc from the terminal to the wire if its held close enough.

    It you are getting a spark, check the gap between your ignitor and pilot hood. It may need to be bent closer. Also, if the hood has a lot of corrosion on it, it will be hard to get a good spark so it may need to be cleaned off with a stiff brush or piece of emery cloth.

  36. jamers423

    With IPI (intermittent pilot ignition) units, the pilot light is self igniting. I assume the main burner goes out when you hear the clicking noise?

    If so, the clicking noise is most likely your pilot light attempting to re-light because it is not sensing the pilot flame. This can happen if the flame rectifier (the metal rod near the pilot assembly) becomes dirty or coated with deposits and does not sense the flame. It can also happen if there is blockage in the vent, the glass assembly is not latch properly, or logs are out of place.

  37. Michele williams

    Our gas fireplace is turning on spontaneously during the night. We have a remote control device not a wall switch. Should we call a technician?

    • mygasfireplacerepair

      Does your remote control have a built in thermostat feature? Check to make sure this is not activated. If not, your remote control could be faulty and would need to be replaced

  38. mygasfireplacerepair

    Sounds like the “flame control” toggle switch underneath the fireplace is bad. You confirm this by bypassing the toggle switch. Try pulling the wires out of the back and connecting them with a jumper wire.

  39. mygasfireplacerepair

    This is normal. This looks like an IPI system with an ignitor and flame rectifier (instead of a thermocouple/thermopile)

  40. mygasfireplacerepair

    Try bending the ignitor closer to the pilot hood. You may have to replace the pilot assembly as it may be grounding out somewhere.

  41. mygasfireplacerepair

    If you have spark at the module, replace the pilot assembly. The ignitor is surrounded in a white porcelain shell that if it becomes compromised, can ground out the spark. Sometimes you can’t even tell where this is happening. But replacing the pilot assembly should fix this.

    If you are not getting a spark at the module, check the voltage at the plug in (should be 110v) as well as the voltage where it plugs onto the module (should step down to 3.5 volts)

  42. mygasfireplacerepair

    Make sure you see a spark by the pilot light. Sometimes you will hear a click but the spark is grounding out somewhere. Remove the glass and put a lit match to the pilot if you have to in order find out if gas is coming out. If no gas is coming out, make sure there isn’t a wire pulled off the valve (there is usually and orange and a green wire that plug onto the valve). If the orange one is not connected to the valve, the pilot will spark but gas will never be released to the pilot assembly.

  43. Melanie Banbury Brownlee

    What is the recommended annual maintenance for a gas fireplace? I have one that we haven’t cleaned, serviced or anything in 10 years, but works fine. Should I do anything with it?

    • mygasfireplacerepair

      Every fireplace brand recommends an annual cleaning and inspection of your appliance. Generally, they are extremely safe and if you do not have it serviced annually, you will be okay. But sometimes is better to error on the safe side. If its been 10 years, it might not be a bad idea.

  44. mygasfireplacerepair

    You should just need to replace the ignitor. Its usually not a difficult thing to replace. Most of the time, they have tabs that hold it into a metal piece that you would need to pinch together to remove it. Other times there is a plastic nut on the backside of the bracket you will need to undo. The ignitor wire should just pull right off.

    • Laura Anne

      where do you get replacement igniters, mine looks like this. it doesn’t spark when you push it, i assume that means it needs to be replaced?

      • mygasfireplacerepair

        Hi Laura,

        You can get replacement igniter here: here

  45. mygasfireplacerepair

    You may have to “re-learn” your remote with your receiver. There is usually a learn or sync button on the module that you press before pressing “on” on your remote to re-sync the remote transmitter.

  46. Paul


    Gas fireplace ……The wall switch is it different than a normal switch that has to be used and if so what type do I need to purchase

    • mygasfireplacerepair

      Hi Paul,

      You can use a normal wall switch (single pole switch). if you are more ambitious you could replace it with a commercial grade wall switch which uses stainless steel parts inside and will prevent the wall switch from failing.

  47. mygasfireplacerepair

    This is a tough one because it really depends on the condition of the fireplace. just like any other appliance, they do not last forever. Usually you know its time to give up repairing when there is a ton of rust all over the place and/or parts are no longer available.

  48. mygasfireplacerepair

    If the pilot lights but continues to spark, then this would indicate that the rectifier (one of the probes) would need to be cleaned because it is not sensing the pilot. If you can see it spark, but it is not lighting then there either isn’t gas getting to the pilot assembly (this is commonly called excessive bleed-back) or the spark is not hot enough to ignite the flame.

    Excessive bleed-back can indicate a defect in the main control valve. When not using the fireplace for a while, this can sometimes cause air to back up in the valve and pilot tube so it will take a while for the air to bleed out and get to the gas itself. But if the pilot is lighting but continuing to spark, i would replace the pilot assembly (rather than clean it).

  49. mygasfireplacerepair

    Does the pilot light continue to spark after it is lit? This would indicate that is is not sensing the pilot flame. This can be fixed by cleaning off the pilot assembly and “probes” with emery cloth or a $1 bill or replacing the pilot assembly.

  50. mygasfireplacerepair

    The white deposit is a mineral deposit that forms from natural gas combusion and is inevitable. There are a few thing you can do to reduce this, however. Make sure there are not too many embers on the main burner as well as checking for excess silicone. Also make sure that any logs or glass media near the pilot is far enough away that it is not affected by the pilot flame when it runs.

  51. mygasfireplacerepair

    The problem may be:
    1. Gas supply (excessive bleedback or gas cock not fully open)
    2. Spark gap (make sure the ignitor and pilot hood gap is 1/8″)
    3. Module is not grounded (this is located on the bracket directly above the valve, make sure the wire and screw are tight)
    4. Module voltage output / Valve/Pilot solenoid ohms readings (this would require some tests with a voltage meter – I will e-mail you instructions on this in case you want to try to diagnose this).

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