So glad to find this forum! Please help me with my direct vent gas fireplace!

[Wayne0871]

Have a Superior direct vent gas fireplace that is about 7 years old, and modestly used with natural gas only. It makes a weird sweet smell after it is turned on for some time, saying 10~15 mins. The smell gets unpleasantly stronger with time. When the fireplace is not in use, there is no smell whatsoever, and I could feel some cold air flowing out of the fireplace.

I have called tech to check and no gas line leak is found (no rotten egg smell either). The pilot hood (basically the pilot line nozzle) does show signs of corrosion, but I have a hard time to conclude this could cause the sweet smell.

The possible root cause that I could think of: residual gas due to poor ventilation? outgassing from something in the vent pipe or in fireplace ? I just cannot find a good explanation for the sweet smell.

 

[DAKSY]

Superior makes a lot of different dv fireplace models. Please specify which one you have.

 

[Ashful]

One of my wood stoves smells like mud the first time it’s burned after sitting cold a few days, it’s the moisture baking out of the mud-stacked stone walls of the fireplace in which it sits. The other stove, which sits in the old kitchen fireplace, has an odd sweet smell that I’ve never been able to identify. Ive assumed it is some paint or oil used in its manufacture, but still somehow smelling only when it gets real hot, after 8 years of daily use. Since it’s a pleasant smell, I haven’t put much effort into finding its source. Heck, maybe I’m smelling what some prior resident cooked in the fireplace in which it sits.

Point is, when metals and paints get hot, they usually emit some smell. Good to understand the source of it, if you think it’s an indicator of some potential safety issue (hot wood? Stove back-venting into house?), but it might also be inherent to the materials used in the stove’s construction, and may never go away.

You didn’t say this is a new problem, so I’m assuming it’s been making this smell for the entirety of the 7 years you’ve owned it?

 

[Wayne0871]

Superior makes a lot of different dv fireplace models. Please specify which one you have.

It is DRT2035, rear vent.

I ran more tests today. When I take the glass door off, the fireplace runs without smell, there is a little bit of rotten egg smell, which should not be a surprise since now the door is gone. Then I put the door back on. After running for 15 mins, the smell could be immediately noticed the moment I turn the fireplace off. It seems the smell is caused by poor ventilation? or some sort of outgassing?

Before I turned the fireplace on for the tests, I did try to feel the airflow with my hand. I could feel the air flowing in from the vent, and also in the lower compartment. I was also able to see the rear vent baffle.

BTW, I was not able to find the air shutter in the lower compartment. According to the manual, that is where it should be.

 

[Wayne0871]

One of my wood stoves smells like mud the first time it’s burned after sitting cold a few days, it’s the moisture baking out of the mud-stacked stone walls of the fireplace in which it sits. The other stove, which sits in the old kitchen fireplace, has an odd sweet smell that I’ve never been able to identify. Ive assumed it is some paint or oil used in its manufacture, but still somehow smelling only when it gets real hot, after 8 years of daily use. Since it’s a pleasant smell, I haven’t put much effort into finding its source. Heck, maybe I’m smelling what some prior resident cooked in the fireplace in which it sits.

Point is, when metals and paints get hot, they usually emit some smell. Good to understand the source of it, if you think it’s an indicator of some potential safety issue (hot wood? Stove back-venting into house?), but it might also be inherent to the materials used in the stove’s construction, and may never go away.

You didn’t say this is a new problem, so I’m assuming it’s been making this smell for the entirety of the 7 years you’ve owned it?

Yes, it has always been there. It has just been used a lot more in the last a couple of years.

I did feel the smell could also be caused by metal or maybe the coating material on the metal, some sort of outgassing. But I don't have a way to test it. It is a irritating smell, so would like to get rid of it if possible.

 

[DAKSY]

Not sure how many consecutive hours you’ve burned the unit, but the outgassing from the oils, adhesives, paints & other materials, takes a good 4-8 hours burning on HIGH. If it continues after that initial burn off, many times it’s from pet hair, dander or dust that has settled on top of the unit or on the heat exchanger & also has to be burned off.

 

[Wayne0871]

Not sure how many consecutive hours you’ve burned the unit, but the outgassing from the oils, adhesives, paints & other materials, takes a good 4-8 hours burning on HIGH. If it continues after that initial burn off, many times it’s from pet hair, dander or dust that has settled on top of the unit or on the heat exchanger & also has to be burned off.

Where and how can I set the fireplace burning on HIGH for burn-off? I did not find this option in manual (P/N 900948-00 REV. E 07/20). It is actually a good idea to try.
The first owner owns the property for about one year, not sure if he did burn off or how long time he used the fireplace. In the next 4 years, it was probably used only around 15 hours per year. In the last two years, it used a lot more but I don't have any number, maybe around 50~75 hours per year? That is a very rough estimate.

 

[DAKSY]

Can you post a pic of the gas valve?

 

[Wayne0871]

Can you post a pic of the gas valve?

This is the best picture I can find at the moment. Unfortunately, it does not show the ADJ screw clearly. It is one of the screws as marked by the arrow.
The circle in yellow is NOT about the ADJ screw position. That is for another question I asked someone else a while ago.