Furnace smell

TravelTiger

Founding Texas-West Chapter Leaders-Retired
I've read all the posts I can about furnace smell, and I'm not finding enough info.

We have a 2016 Big Country, purchased in January of 2016. We did run the furnace in early 2016, and the again in late 2016 and early 2017. Now it's late 2017, and we still have a bothersome odor from the furnace when it runs. I ran the unit a good couple of hours this week to start the season, so it was ready before it got colder, with windows open, hoping to rid us of the smell. The propane bottles are newly filled.

We fulltime, have induction cooktop and a LP fridge that we mostly run on electric, water heater runs on electric, so really the only time we use a propane is in the winter.

The smell is kind of a sweet/burnt smell, from all vents. Not a "dead" smell. Not a raw propane smell. The exhaust outside smells less offensive than inside. It starts off not too bad but longer the unit runs, the more bothersome it becomes to me, such that I feel like I might gag. Since the furnace tends to only run a short time and stop (a normal cycle), it's "tolerable" and I've assumed I'm just overly sensitive. But I certainly don't want to keep running it if there's an actual problem.

We have two CO detectors, and one is even directly over a heating vent. Neither has indicated an issue, and both have fresh batteries.

For a "regular Joe", what's the best course of action to find out if this is normal or not? I can call "the man" if I need to, but want to make sure I have exhausted the things we can look for ourselves, first.


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uncledon

Her chauffeur
I've read all the posts I can about furnace smell, and I'm not finding enough info.

We have a 2016 Big Country, purchased in January of 2016. We did run the furnace in early 2016, and the again in late 2016 and early 2017. Now it's late 2017, and we still have a bothersome odor from the furnace when it runs. I ran the unit a good couple of hours this week to start the season, so it was ready before it got colder, with windows open, hoping to rid us of the smell. The propane bottles are newly filled.

We fulltime, have induction cooktop and a LP fridge that we mostly run on electric, water heater runs on electric, so really the only time we use a propane is in the winter.

The smell is kind of a sweet/burnt smell, from all vents. Not a "dead" smell. Not a raw propane smell. The exhaust outside smells less offensive than inside. It starts off not too bad but longer the unit runs, the more bothersome it becomes to me, such that I feel like I might gag. Since the furnace tends to only run a short time and stop (a normal cycle), it's "tolerable" and I've assumed I'm just overly sensitive. But I certainly don't want to keep running it if there's an actual problem.

We have two CO detectors, and one is even directly over a heating vent. Neither has indicated an issue, and both have fresh batteries.

For a "regular Joe", what's the best course of action to find out if this is normal or not? I can call "the man" if I need to, but want to make sure I have exhausted the things we can look for ourselves, first.


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Just a suggestion...can you access the furnace where the foil vents attach and remove them to see if the odor is coming from the furnace and not from inside the vent runs? Might give a clue anyway.

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danemayer

Well-known member
Erika,

Make sure there's clearance all the way around and that nothing is resting on the furnace cabinet behind the basement wall.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Screen Shot 2017-10-30 at 1.00.53 PM.jpg

Just for reference, here's a photo from April 2016. I haven't a more recent picture.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Looks like some wires resting on the furnace at top right. Might be insulation.

It doesn't smell like electrical or plastic smell.

Based on this picture, can I assume it's drawing "fresh" air from the space around it? The vent for return is on the (interior) wall to the left.


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danemayer

Well-known member
It doesn't smell like electrical or plastic smell.

Based on this picture, can I assume it's drawing "fresh" air from the space around it? The vent for return is on the (interior) wall to the left.


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That's what I would think. There's also some combustion air drawn in from outside through one of the round vents.
 

PondSkum

Well-known member
Sorry I do not have an answer to your question. I'm here for the same reason so I will follow this thread. I just bought my 2015 Road Warrior earlier this year, and just fired up the furnace this weekend to test it for the first time. I don't believe the previous owner ever ran it either. I let it run for about an hour, and it still had a funny smell coming out of it. Had to open all the windows and door to vent the smell out. I did read in the manual that initial run could cause some smell from the "new" burning off, but I think it said the first 20 mins or so. I guess I could go read the manual again and see what it said, but what fun is that? Looking for real world experience here!! LOL

- - - Updated - - -

Went back to the manual.. it states:

"NOTE: During initial firing of this furnace, a burn-off of excess paint and oils remaining from manufacturing process may cause "smoking" for 5 - 10 minutes."


But it seems that the smell lasts longer than that 5-10 mins...
 

jerryjay11

Well-known member
A couple things other than oils from a RV furnace being new. 1) Dust can collect on and around the furnace including the air ducts which will give off an odor while heating. Most of the time if would burn off and the odor will clear up. 2) The furnace is a favorite place for little critters to build a nest. Their nest can smolder, even burn giving off the off smell. They can leave dropping in the air ducts which as well can product an odor. Worst case you could be broiling their little bodies which may take some time before they are done.

Best thing is to remove the furnace and check the heat exchanger for anything that doesn't belong there. If you are not comfortable to pull the furnace out then it is for "The Man" to do.
 

cookie

Administrator
Staff member
E, I think that Uncledon had a great idea to isolate where the odor might be coming from.
I suggest starting there.

Peace
Dave
 

NewHopians

Active Member
From your picture and being such a confined space you could be getting the heat build. This build up can be causing the ABS piping glue to heat and off gas. When it shuts down the off gassing quits until it gets warmed back up. Maybe some insulation keeping the heat away from piping will help. Being a fire fighter we have found this glue gives a sweet to almost puntient odor when heated. Hope this helps.
 

RoadJunkie

Well-known member
Ours, like most rigs out there, have a misbalanced heat flow throughout the vents within the coach; You can fry eggs on the bathroom vent while some others are lukewarm. I'm wondering if the vinyl flooring in the bathroom is getting so hot that it is out-gassing? Maybe try to isolate the bathroom duct to test?
 

jbeletti

Well-known member
Erika - your picture shows 2 vents on the right side with no ducts connected. They don't look like they're blocked off. Wondering if super-warm air is coming out of them and heating up the items/surfaces next to them??
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Erika - your picture shows 2 vents on the right side with no ducts connected. They don't look like they're blocked off. Wondering if super-warm air is coming out of them and heating up the items/surfaces next to them??

Yes after looking back at it, this was taken when we had a minor flood in the bathroom and We removed them to check for water and make sure no liquid got into the furnace. The ducts are there, I am pretty sure! I have heat coming out all vents.


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TravelTiger

Founding Texas-West Chapter Leaders-Retired
Ours, like most rigs out there, have a misbalanced heat flow throughout the vents within the coach; You can fry eggs on the bathroom vent while some others are lukewarm. I'm wondering if the vinyl flooring in the bathroom is getting so hot that it is out-gassing? Maybe try to isolate the bathroom duct to test?

The smell is from all vents. More intense in the bath and bedroom, because they are pushing out a little more air. I do have a damper for the bathroom but have not closed it down any this season so far.


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TravelTiger

Founding Texas-West Chapter Leaders-Retired
The smell is from all vents. More intense in the bath and bedroom, because they are pushing out a little more air. I do have a damper for the bathroom but have not closed it down any this season so far.


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Oh but after I posted this, I realized the furnace does rest on vinyl flooring. Hmmm.


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jbeletti

Well-known member
Yes after looking back at it, this was taken when we had a minor flood in the bathroom and We removed them to check for water and make sure no liquid got into the furnace. The ducts are there, I am pretty sure! I have heat coming out all vents.
Cool. One thing eliminated as your issue. While it's quite an effort, the suggestion to remove all ducts from the furnace for a visual inspection is a good one. The back of the furnace is held together with a couple of screws. If I went to the trouble of getting to the furnace and removing the ducts, I'd absolutely take the furnace back off while I was there.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Cool. One thing eliminated as your issue. While it's quite an effort, the suggestion to remove all ducts from the furnace for a visual inspection is a good one. The back of the furnace is held together with a couple of screws. If I went to the trouble of getting to the furnace and removing the ducts, I'd absolutely take the furnace back off while I was there.

Thanks, sounds like my weekend plan. Lol! There's actually a surprising amount of space back in there, but not as easy for a "Big Guy".


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jbeletti

Well-known member
Thanks, sounds like my weekend plan. Lol! There's actually a surprising amount of space back in there, but not as easy for a "Big Guy".

Consider this as your process:
  1. Using a Sharpie, number each duct and where it connects to the furnace
  2. Using a nut driver, loosen the hose-clamp that holds the duct to the collar on each furnace duct and twist/pull ducts and clamps off collars
  3. Use a flashlight to illuminate the interior of the furnace and use your phone to snap a bunch of pictures
  4. If you're up for is, take a Phillips head and #2 Square head screwdrivers with you. Find and remove the 2 or so screws that hold the backplate on the furnace and remove the plate. Illuminate, photograph and inspect all areas in the furnace you can see
  5. Assuming you have a Suburban (or perhaps you have an Atwood) furnace, outside, remove the screws on the exhaust port plate and the screws on the furnace cover. Pull straight out on the exhaust port to remove it. Then remove furnace cover. Inspect for webs, critters etc.
 

TravelTiger

Founding Texas-West Chapter Leaders-Retired
Consider this as your process:
  1. Using a Sharpie, number each duct and where it connects to the furnace
  2. Using a nut driver, loosen the hose-clamp that holds the duct to the collar on each furnace duct and twist/pull ducts and clamps off collars
  3. Use a flashlight to illuminate the interior of the furnace and use your phone to snap a bunch of pictures
  4. If you're up for is, take a Phillips head and #2 Square head screwdrivers with you. Find and remove the 2 or so screws that hold the backplate on the furnace and remove the plate. Illuminate, photograph and inspect all areas in the furnace you can see
  5. Assuming you have a Suburban (or perhaps you have an Atwood) furnace, outside, remove the screws on the exhaust port plate and the screws on the furnace cover. Pull straight out on the exhaust port to remove it. Then remove furnace cover. Inspect for webs, critters etc.

Thanks Jim, sounds like a plan. We should have decent weather to look into this. I was thinking there has to be stuff we can do to check before considering hiring a tech. (The 3-day class Tony took in Goshen did not cover furnaces to this extent.)

I appreciate all the suggestions, I will report back when we know something!


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