Fireplaces, Heating Stoves, Flues and Chimneys - gas fireplace-flame and pilot light going out

We had a friend install a gas fireplace (a direct vent DESA CTDV36NRA) this winter and we are having trouble with the flame and pilot light going out on there own.
We had professionals install the gas line and they came out again to douple check that the gas pressure was ok and it was. We even switched out the fireplace for a new one thinking that it was defective but the new one does the same thing.
It does go out more freq. when it is set on high. If if is set on low it rarely goes out except for when it is really cold outside. We douple checked the venting for leaks and nothing blocking the vent and it was all ok. It may be ventilation related, I once opened the front glass and ran it and on high, it ran great-the flame looked bigger and nicer than normal and it did not go out, than after closing the glass up it went out within a few minutes.
Any ideas would be appreciated.

Direct vent? Are you saying vented or ventless. The "vented" type must have some way for combustion gasses to escape. The "ventless" type will operate in a closed firebox and combustion gasses escape into the room.

I have no experience with the "vented" type. Sorry.

The "ventless" type and maybe the "vented" too, will have an oxygen depletion censor. This device will turn off the gas if low oxygen is detected. This sounds like what you are describing. With the doors closed there must be some other way for air/oxygen to enter the firebox.

What you have there is the potential to create deadly carbon monoxide. Please have a professional check the installation. Sorry if this response is blunt but it just isn't worth the risk to save a few bucks.

It is a sealed firebox that expells exhast gases outside, so it is vented. thanks for the reply, professional help was going to be our next step.

Sounds like you are having what's called flame lift off. There is probably an issue with the vent pipe connections allowing the exhaust gasses to contaminate the fresh air. Time to call a professional.

DO NOT OPERATE THIS WITH THE GLASS OPEN !!!! You and your family could lose your life.

I once opened the front glass and ran it and on high, it ran great-the flame looked bigger and nicer than normal and it did not go out, than after closing the glass up it went out within a few minutes.

You say what the cause is right there . The O.D.S. SENSOR
That tell it to shut off after the oxygen depletion sensor built in shut it down .;) ;)

Direct vent gas fireplaces do not have an ODS pilot assembly, neither do vented units. The ODS is required on vent free gas burners.

Au contrare my friend. A gas log is a gas burner and they do have ODS pilot light assemblies.
Your problem is a clogged air vent hole in the pilot air intake. This hole is located about 2" back down the pilot tube from the flame front. You can blow it out with a can of compressed air. You should notice also that the pilot flame has a lot of yeloow color to it. Thats incomplete combustion due to improper air/fuel mixture (the plugged air intake hole) This should also be causing a black sooty buildup on the gas manifold where the pilot light impinges on it to light the burn. This web site should help...has a picture of the 4 most ccommon ods pilots and shows you where the air hole to clean out is....

http://www.rasmussen.biz/troubleshooting/chillbuster_vent.htm

LKG, the diagrams displayed on the link are for ODS pilot sensors. These are found primarily on vent free fireplaces and heaters. While I under stand and agree with what you say about the pilot air intake being dirty, that shouldn't create the problems described with the flame lift.

Direct vent fireplaces are a completely different animal. Yes, they still have the air intake on the pilot (and create similar signs when clogged), but the combustion air for the fireplace comes from outside the home. Being the intake vent and exhaust vent are inside one another can cause the results described if the integrity of the exhaust vent is compromised. The exhaust will mix in with the combustion air contaminating it and ultimately snuff out the burner.

Other problems that can be causing the problem are:

Improperly run vent pipe. Check the installation instructions to make sure distances and amount of elbows aren't exceeded.

Improperly installed vent termination if using a square side wall mounted termination. Make sure the clearances from other exterior walls are followed. Too close to corners of the house can create poor air exchange

This unit IS a direct vent and not a ventfree, so forget the ODS pilot.

http://12.153.20.72/tech/manuals/111250-01D.pdf

Sounds like oxygen starvation from improper venting. This can be a problem with the vent connections, it could be in the venting configuration or the installer may have left some packing in the appliance collar on the unit.

Shut the unit off and have a pro check it out.

HTH,
Hearthman

I want to thank you for posting that link. I had tried to figure out where I needed to clean out my pilot area. I would lite it and it would stay on but as soon as I turned on the fireplace it would cut right off. I took a flash light and looked inside the area where the pilot lights and I found a hard round little black burned ball. It looked like BB but it was not. I got that out and my fire place is working wonderfully.

Thank you so much for all the wonderful information and linksBeer 4U2

We just purchased a two year old jotel gas stove. It is direct vent and when we light it it shuts off after 10 seconds. We had a plumber do the vent system but the dealer is saying it sounds like a vent problem. We have a snorkel vent that is in a window well two feet below grade. Below the bottom of the snorkel vent is a foot and a half space. Does this sound like a vent problem or something else. The flame is blue colored no matter if we have it on low or high it goes out in about 10 seconds.

I have a desa direct vent fireplace model VT36PRB, can I go to ANY fireplace store and buy the flue pipe and everything else I need to vent this outside? I bought my house with this fireplace in and it was not vented outside or hookup anywhere.
I have called desa and have been on hold for 45 minutes. PLEASE someone help me

I can't seem to keep my pilot light going after I switch the button to on. The igniter works but the pilot light will not continue to burn. Suggestions.