New Install, only will run for up to 10 min

[Toniko]

We just installed our natural gas fireplace. The pilot lights easily with just one push and it will run sometimes for up to 30 minutes just fine but more times than not it will go out after 5 minutes or so. I noticed that the flame is very blue and am wondering if that means anything? Thanks!

 

[DAKSY]

What kind of unit?
Manufacturer & Model will help.
Direct Vent? B-Vent? Unvented?
Natural Gas? Propane?
More info please.

 

[DAKSY]

What kind of unit?
Manufacturer & Model will help.
Direct Vent? B-Vent? Unvented?
Natural Gas? Propane?
More info please.

 

[Toniko]

Sorry,
it is a "FMI Products" unit Model CTDV36NR-A
direct vent
natural gas
I saw a post online an hour ago saying to let it run with the glass open for a while, although I have done it for maybe 1-2 min before I tried it for more like 10 minutes(the flame was very orange at that time) then shut the door(it turned very blue when I did this). It does seem to be running well now, less blue flame more orange. Should this be necessary each time? We sort of just plan to use it for its looks so were not planning on keeping the pilot lit all the time(Or is that best for the unit?)

 

[DAKSY]

Ok. I'm not familiar with that particular unit, but most of them operate the same way.
Does the "Blue Flame" ghost & lift off the burner before it goes out? Sounds like you have a venting issue.
Is the pilot running all the time or does it only come on to ignite the burner?

 

[Toniko]

The pilot runs even when the burner is in the on position.
When I look up through the glass I can see right to outside through the exhaust pipe (it is just one elbow then right to outside).
I will keep an eye on it today I turned off the burner using my remote for an 1/2 hour then tried turning it back on and now am not having trouble. Maybe I will turn the pilot light off for a while here and start over to see if I can get it to do it again.

 

[DAKSY]

With the pilot running, there will be some convection as the pilot will create a small a amount of draft. If the pilot is off, the air pressure & temperature inside & outside the firebox will normalize & level out...A fresh start may be troublesome in this condition. I'd try to light the pilot & wait a few minutes to get the direct vent working, THEN light the burner...

 

[Toniko]

Ok, I have an update, I've found that lighting the pilot with the glass open, and then lighting the main burner (still with the glass open) for a few minutes, then close it up, it will run fine for as long as I want to have it on. The problem is if I turn off the main burner (pilot still on) and then come back to it the next day it will usually only run for a few minutes, the flame is mostly or all blue, and then it shuts off. As mentioned before, the vent coming off the fire box is up at a 45deg angle, then I attached a 45 deg elbow to make it run horizontal, with an extendable pipe, about 8", to outside. The vent outside is about 5 feet off the ground. All the venting parts were the proper parts for the fireplace and the venting setup follows one of the accepted methods from the manual. Could the lack of oxygen still be due to a venting issue? At this point I'm at a loss, and the closest fireplace dealer here won't look at it because we didn't buy it from them. Any other help or suggestions is greatly appreciated.

 

[DAKSY]

You may have a "reverse venting" occurring. If your unit starts to vent thru the intake & try to draw combustion air thru the exhaust side, It can't get enough air thru the smaller pipe to support the combustion. The only time I've seen this is with gas inserts, tho, never with a fireplace or stove...Have you checked the millivolt reading on the Thermopile? Maybe if you turned it up to about 600 mV it may stop the reversal...Kinda grasping at straws, but a blue ghosting flame is generally an indication of a venting issue...

 

[STOVEGUY11]

Is it a corner install, or flat on the wall? A picture of the set up may help as well.

 

[Toniko]

Thank you for all of the advice! We called the company they said the venting is not angled enough and we need to reinstall the double walled pipe at 1 inch more of an incline. We did not install the cement board on face yet so pulling it out is possible, just time consuming! Hoping it works

 

[Toniko]

I pulled the fireplace out again to see what I could do to re-run the vent with more of a vertical rise, but at this point I don't have the additional vent pieces I would need to complete the venting, so while the unit was out I took some pictures to show what the current venting looks like, the pictures show the 45 deg pipe, straight adjustable piece, the wall firestop and high wind termination. I followed the installation manual exactly as described for a standard ground floor installation (manual here, see page 11). We have a bump-out on one wall in our living room, so the fireplace would be flush with the wall when installed. Since the company recommended having more of a vertical rise (even though I told them I installed it per the manual), one thought was to flip the 45 around so it comes off the fireplace vertically and then do a straight pipe to a 90 degree elbow and then horizontal straight pipe to the wall (fig. 9 on page 9 of manual), although I'm not sure that would work either if there is a horizontal piece of pipe that could cause a problem for the air flow.

 

[DAKSY]

Why not run the straight section off the flue collar FIRST then the 45 to the cap? That will give you a little more vertical rise.

 

[Toniko]

I actually was going to do that but the 45 isn't long enough on one end to reach through the firestop to the exterior termination. I also thought about putting another piece of straight pipe on the other end of the 45 to reach through the firestop, but the piece I have is too long when added to the 45. I thought this straight piece (min. 9") was as short as I could get, but found one that is just 6" that I will buy today. Then, as you said, I would have a straight piece off the flue, to a 45, then a short piece straight through the wall to the termination. I'm hoping that will actually make a difference and allow it to vent properly removing the ghost flame/oxygen issue, from what you can tell do you think that might work?

 

[DAKSY]

I actually was going to do that but the 45 isn't long enough on one end to reach through the firestop to the exterior termination. I also thought about putting another piece of straight pipe on the other end of the 45 to reach through the firestop, but the piece I have is too long when added to the 45. I thought this straight piece (min. 9") was as short as I could get, but found one that is just 6" that I will buy today. Then, as you said, I would have a straight piece off the flue, to a 45, then a short piece straight through the wall to the termination. I'm hoping that will actually make a difference and allow it to vent properly removing the ghost flame/oxygen issue, from what you can tell do you think that might work?

It can't hurt...

 

[Toniko]

It did not help so I called the company for the 3rd time and they gave me the contact info for their lead installer. He told me the directions in the book for log placement are garbage and instructed me on how to position them properly. So far so good! I will be calling the company back to let them know how well and easily he helpped us out. Flame is a beautiful orange

 

[DAKSY]

It did not help so I called the company for the 3rd time and they gave me the contact info for their lead installer. He told me the directions in the book for log placement are garbage and instructed me on how to position them properly. So far so good! I will be calling the company back to let them know how well and easily he helpped us out. Flame is a beautiful orange

You DON'T want ORANGE flames. You want YELLOW flames. If your flames a tending towards ORANGE, there still may be an adjustment needed. The air shutter on the burner should be opened a little more. Open it in 1/8" increments until the flames are BLUE at the burner & YELLOW at the top. That is the CORRECT flame appearance...