Extinguishment Pop and Crazy Hot Kingsman Fireplace

[Brooks89]

Just had a 39" LP Kingsman Bentley Marquis Fireplace installed and wondering if anyone can help answer a few questions!

A) This is a Heater Rated unit and installed with a reflective black porcelain liner, driftwood log set and "glass media". I am wondering if we had instead ordered a "brick pattern" refractory liner, traditional log set with lava rocks lining the bottom of the unit would less heat be reflected into our living area?

B) Often when the unit is turned off as the valve shuts off and the flames die down the unit will flare up momentarily with a "Pop" before completely extinguishing. My installer is questioning the pressure setting of our LP tank regulator...Called my bottled gas supplier and they are willing to come test for a $150 service fee but seem to feel if we have no issues with our gas range it's likely the regulator is within spec. Kingsman looked at a video of the Pop and tells me they are "doing a test" and may need to replace the burner pan... anyone have similar issues and were you able to resolve them?

Any insight would be great!

 

[DAKSY]

That pop appears to be from "puddled" LP, probably BELOW the burner.
I would check the burner tube/burner orifice alignment. If the orifice is
not aimed DIRECTLY into the burner tube, LP can shoot out of the air shutter
& accumulate at the bottom of the firebox. When the gas is shut off to the
burner pan, that "puddled" gas will be ignited by the pilot. Just my $.02...

 

[Tech Guru]

I'd have disagree with DAKSY, as much as it pains me to do so. as far as what I see: this is classic extinguishing pops when the gas pools in the burner and makes this type of shutdown. It's not nearly as severe as some that I've seen (all kinds of makes and models). The principle is the same as what DAKSY states: The gas, when the burner shuts off, has no pressure pushing it through the burner any longer, so in some cases when the fuel does not completely burn away as it evacuates the burner, it can pool enough to flare up once it meanders its way out to a source of ignition (often the pilot or a pocket of flame/ember material that may remain burning). It can often be helped with ember material placement methods. Essentially the only test that I'd be concerned with is a pressure check to ensure that the valve outlet (manifold) pressure drops immediately and all the way to zero when the main flame is turned off - not that I'd be too interested in paying someone $150 to tell me that it indeed behaves properly.

I've seen burner replacements (again other makes and models) do absolutely nothing to remedy this, but a simple rejigging of the burner media can rectify this.

 

[Tech Guru]

As for the heat, it would likely make little to no difference what style of burner kit and liner panels you have. If anything, the brick panels can be more of an issue as they are normally comprised of a ceramic fiber material, which is an excellent insulator. in many cases the brick kit options make the fireplace more effective of a heater, rather than less . as long as the fireplace was converted properly and the pressures are where they should be you're going to get what you're going to get...

 

[Brooks89]

Thank you both for the input! Kingsman is offering a replacement burner under warranty but pretty much under the premise that "it might help". Interestingly I did remove the log set set and glass media and re-installed it and does seem to help with the occurrence of extinguishment pop but not completely eliminated it. And is apparent that "re-jiggering" the glass media slightly does indeed seem to effect flame behavior. The installation tech did not use any of the small "glowing ember" pieces supplied with the fireplace, but the log set does give a nice ember effect. Which makes me wonder, what if I removed the glass media from the burner pan and replaced it with the "glowing ember" material, instead leaving the balance of the glass media around the perimeter of the burner pan? (It's black glass media, so it seems like when the unit is off, it would not look objectionable) Do you think using the ember material which is less dense would allow the gas to burn off more rapidly/completely rather than "pool" in the glass media?

Just a clarification, the $150 charge is from my propane provider to verify LP pressure coming from the regulator on my supply tank. They installed my tank 3 years ago and are doubtful there's any issue with pressure...

Thanks again!