Horrible, Awful, Stinky, etc......FURNANCE HEATER SMELL!!!

[Fosters]

My 1st 5th Wheel (or RV for that manner) so an LP furnace new to me. We all know that in a regular house dwelling that has Natural Gas and one has a leak, it smells like "bad eggs" right? Well, the smell in my coach is not bad eggs when I put the heat on, so it is not a leak. Assuming Natural Gas leak smells the same as LP Gas? Nevertheless, I well believe it is NOT a LP leak I have.

It is something else. Without you obviously able to smell it, I can try to describe it as certainly something burning and emitting a very nausea odor. A burning smelly odor. No smoke comes from the vents. And it is strongest once she turns on, but never subsides. Kinda lingers. My first winter and been running the heat for like 2 weeks now. And nothing is changing, ain't better ain't worse. And I don't have the funds to have a Pro RV Tech come inspect the system.

I have read some postings elsewhere about mice droppings in the duct work or worse, mice nests!!! Now, I have no idea what a burning mouse smells like. But would love to put one on fire and see if that is my culprit!!! I can buy the fact of a burning mouse causing the odor. But not those very, very little black poop mouse droppings. Unless there is a s**t load of them in my duct work?

Surely, someone has experienced the same at some point? Mice smell or something totally different?

Thanks so much to all of you in advance!

[mchero]

Pull the furnace.

[westend]

As was posted, a rodent infestation means...work. Whether the OP takes it on or hires it out, it is the same. Sure, a single mouse, only nesting once, and having a single litter, then all mice eliminated, may mean less intensive cleanup measures. My experience is that once they move in over the Winter, there is just non-stop procreation and population increase.

A side-benefit from removing the belly covers is that a user can better position ductwork, arrange for better insulation, and the most important, understand what is installed in those spaces. Most guys that get into those locations discover pinched ducts, poor wiring techniques, and insulation that is haphazardly positioned. Member LarryJM did a rearrangement of his under-belly area and has posted pictures and details of his work.

BTW, they don't make enough dryer sheets to eliminate the smell of a full-on infestation.

[subcamper]

Fosters wrote:
And if it is mouse urine, the heat I would imagine has to ultimately "heat out" and dry it all up eventually right?

It's my experience that it won't dry up and the smell go away.

The smell is incredibly tenacious.

You have to remove the urine and/or urine-soaked items (or possibly neutralize them with an enzyme cleaner as others have said).

Steve

[Fosters]

Thx WestEnd, and great fyi for this non-mechanic about the intake/outtakes! So if that is the case and I were (not doing anything till I know what the heck I'm doing 1st!) to use the leaf blower inside by sticking down the vents, if any debris etc were in the duct lines where would it exit? Or rather, would it not and just be pushed up against the heating chamber, etc. (wherever the ducts go from the floor down?)

Again, bought used and the Seller lived in the Jersey Pinelands and the RV sat in his forest of a backyard when not in use (which was largely the case). So I can only imagine......rodent motel!!! Mute point really where or how the rodent problem (if the case but certainly leaning that way....) started. But I like your idea, dropping my Underbelly and a full inspection!!! In a perfect world, I would have done that at the buy, but who knows if the Seller would even have agreed, taking to a shop, etc.... The odor certainly is not getting worse, and actually/maybe might be subsiding some. And if it is mouse urine, the heat I would imagine has to ultimately "heat out" and dry it all up eventually right? But if nest, then of course they keep peeing all over the bloody place too!!!

I want to kill them with poison, but not a good idea because more then likely they will drop dead in the nest or in a duct line, behind my floor kitchen cabs (which have all the tell tale poop signs). So I have layed out Bounce dryer sheets in just about every cab as deterrents or repellents. Key is to get them OUT and then start safeguarding with Bounce sheets, moth balls, Peppermint Oil, and Steel Wool stuffed in every bloody hole that is bigger then 1/2" throughout the entire coach!

This is another venue/forum entirely, but for a luxury Heartland Bighorn 5th, disgrace on all the shortcuts or laziness they did in the build. i.e. leaving wide, like open walls folks!, openings behind the cabinetry on the kitchen floors! Sure, you will see the "Great Stuff" product blown around the wiring but half ass. Some holes ignored completely. Q: Mice have been around for a billion years and the RV industry knows the damage they do. And mice can easily eat away and thru the great stuff. But steel wool, NOOOOOO, NEVER, IMPOSSIBLE. So putting aside the B.S. money costs, why would they not use steel wool around the hole lines and fill in with the great stuff??? Again, another forum and sorry to ramble on, I'm just frustrated.

Thanks again for any help and keep replying!

[westend]

If you've had a "deep" rodent infestation, you have work to do. I'd suggest that you pull the under belly coverings and start inspecting ducts. There is a good chance that you have nests and debris inside the ducts. Probably some holes, as well. Critters play havoc with this stuff and it's not just what you can see/smell on the surface.

Have you used the oven recently? You may be in for a surprise when that heats up, mice love to get into the range and setup house.

BTW, those two openings you've found in the exterior are the fresh air combustion intake and the combustion exhaust. They lead to the burner chamber and are not connected to the duct work.

[subcamper]

My furnace is behind a door with a screen on it. I opened the door and removed the furnace front cover (2 screws), which exposed the heat exchanger, along with the plenum (sheet metal box with 5 holes for the 5 round heat duct going out). The plenum was under the floor, but I could just squeeze a shop vac hose past the heat exchanger and into each of the holes to blow it out. Watch your hand as the edges of the heat exchanger are sharp.

I put the shopvac hose into each of the ducts, then put an upside down box over the floor vent to keep stuff from blowing all over.

I have had to do this every year. One time there was a big mouse nest in one of the ducts which blocked it completely. I had to use a piece of romex cable with the end looped back so there was no sharp edges to break up the nest. The ducts are VERY thin so they will puncture easily.

Steve

[Old-Biscuit]

Listing your RV in signature is nice...but doesn't mean folks will know what BRAND/MODEL of appliances/components were used.

Always post that info when seeking help :B

Go outside and see where furnace intake/exhaust ports are (may have access panel to furnace components but you want other side)
Directly opposite those ports will be were furnace is mounted inside the RV.

Most likely backside of furnace (discharge plenum and duct work) is accessible via 'basement' compartment and behind a false wall or panel.

Sounds like you have something in the discharge plenum...mouse only needs a 1/2" hole to squeeze thru for access

[drsteve]

My bet would be mouse urine. The mice may have fouled the ductwork and/or peed on your furnace heat exchanger. Nature's Miracle Urine Destroyer works well to get rid of the smell. It's an enzyme, not a deodorant, so it has to come in contact with the urine residue, but it works. Cleaning the ducts can be accomplished with an electrician's fish tape and a rag, the furnace will have to come out and be partially disassembled.

[Fosters]

Ok, in answer to the most popular Q, and sad to report, the coach is not brand new. 2009 Heartland Bighorn 3580RL (thought I entered my "rig" info to appear as my Signature so the readers know my equipment but guess not, gotta redo) that I bought this summer. So this theory is ruled out, it is not "new furnace" smell.

Not stinky bugs as I well know that smell. Subcamper I really like your line of thinking. Tell me more! Like exactly how did you blow out the lines? I will follow your instructions. Assuming all know where the furnace is located and the 5th wheel RL (rear living) layout, the smell is predominantly (if maybe even only) coming from the shower/sink area floor vent. And funny enough, would be located directly above the furnace. And that vent, is the strongest odor. The bdrm vent is a very weak odor. Then, as you go down the steps to the Kitchen the 1st kitchen vent has no odor, but appears to not even blowing out heat. Going to test this further. Finally, the 2nd kitchen and final vent in the lounge both blow normal and no odor. So again, odor really just coming from the vent above the furnace outside the toilet door. And I do have an Underbelly as well, just not physically able to crawl underneath to examine. Which is another issue and the problem in the 1st place, how and where are the mice getting in? I have found clear evidence inside the coach and the damage they have done, but that is another forum topic.

Also, in another forum I read where a guy used his leaf blower and a "bunch of stuff came out". Now, would I remove the floor vents and stick the 2' nozzle down as far as I could and blast away? To exit? Outside the coach I have removed the Suburban grate and find 2 nozzles that fit into each other. So will "the stuff in the duct lines if any" easily exit via one of those openings? I'm just assuming one is exhaust and one is air intake, but I'm certainly no furnace mechanic. And these nozzles are only what, some 2" opening, so might even do more damage getting who knows what now CLOGGED in that nozzle coming from the much wider ducts?

Or........would I do the opposite, and use the leaf blower outside the coach from one of those nozzles? And inside, somehow try to figure out how to avoid any **** coming out to fly all over the place inside the coach!!! I have a total of 5 floor vents! That's me outside and 5 people inside sitting above the vent with a Hefty bag....LOL!!! Ridiculous.

I hope I addressed everyone's Q and advice and thanks again!

[Dennis12]

How about those wonderful stink bugs ?? Just a thought

[mgirardo]

The last two campers we have owned were bought new. I never experienced an odor of anything burning off for more than a minute or two. When we fire up the furnace for the first time, we generally have a smell of burning dust and other things in the duct work. It lasts a minute at most and then there is no odor again until the furnace sits for a long time without being run. Yes, the odor is horrible, awful, stinky, etc., but it doesn't last more than a minute.

Since the OP has been running his/her furnance for the last 2 weeks, I don't really think anything in the furnace is still burning up. There is a good possibility that something got in the duct work and died and that is what you smell. The air doesn't really get hot enough in the duct work to burn anything off.

If your vents aren't in the floor, it shouldn't be too hard to trace the duct work. I would start at the furnace and run a drier vent snake through it and see what comes out the other end. The ducting isn't super sturdy, so don't push the snake through too hard. You can also tie a piece of sturdy twine/rope to the furnace end of the ducting and pull it back to the vent, then empty the ducting. Then pull it back through to the furnace with the rope.

-Michael

[SCVJeff]

If that heater is really circa. 1971, get a CO detector and make sure you keep it on. I had the same issue with the heater in my 85 Pace-Arrow... An Unidentified smell that appeared all of a sudden and turned out that the burner tube had developed a hole in it and you could see flame leaking out. What the smell was I don't know, but I think it was like rotten eggs. Been awhile.

Needless to say it was dead

(edit: oops... no idea where "1971 came from)

[subcamper]

I had mice build a nest in one of the heat ducts leading from the furnace to the floor vent. It stunk really bad. The ducts are just super-thin foil with a spiral wire through it. The mice chewed a hole through the foil under the floor (we have a underbelly cover) to get access.

Check the smell at each vent to see if its everywhere or just one line. The mouse urine smell is really bad when heated.

I ended up blowing the nest out with a shop vac. Then I repaired the chewed spot with aluminum duct tape. Finally, I blew lysol through the line with the shop vac to disinfect as much as possible. It still took a long time to get rid of the smell.

Steve

[joebedford]

He said he's been running the furnace for two weeks. It's not new furnace smell nor dead critter in the hot side of the furnace. Those smells would have burnt off by now.

I'm guessing dead critter in the cold side ducts.