Dead mouse or something: How to find?

I would try and pull down some of the duct work to locate any dead critters. After you've gotten rid of them, consider installing 1/4" hardware cloth in the ducts. That way, you'll prevent it happening again.

Found the problem: Headed down to New Mexico to enjoy warmer weather (little need for a furnace). Taking the advice of a few dealers I thought I'd let the mouse dry out down here. Talked w the mfg several times to verify the structure of ducts, underbelly, etc so I could guestimate where the dead mouse was (the ordor was only when the furnace was running). Then deciding its time to head north soon, fired up the furnace to see if the odor improved. It did not. As a result I decided to pull my furnace and find the mouse.

Pulling the furnace I found no dead mouse or evidence of a mouse presence anywhere. SInce I had the furnace out I took it to a dealer to test. They found the furnace was leaking propane at the gas/heat exchanger connection. It was so loose (note I bought this RV in January 2017) it failed the bubble leak test by literally blowing the leak test fluid off. The fitting was only finger tight. So what I was smelling was propane as I origianlly suspected, and a RV leak test would not have found this. The furnace would have to be running to find the leak.

Then checked my propane detector. How could there be such a stench in the coach and the detector not alarm? I tool a grill lighter, extinguished its flame, and poured that gas over the detector, letting it whiff up around the detector. The alarm never went off. I pushed the alarm test and yes it can make noise. Then I pointed the grill lighter directly into the detector vent, and after 10 seconds the alarm finally went off.

Observations: Not the mfg, or any dealer, ever suggested the furnace could be leaking gas when I told them the odor was only present when the furnace was running.

Lesson learned: Do not trust your propane detector.

Once on our sticks and bricks I could smell what to me was a dead mouse. Searched all over the house for several days. Finally after about a week of searching I found a dead cat under the front porch. Crawled under the deck several times with a shovel and removed what was left of the cat and several scoops of dirt and finally got rid of the smell. Whew, nasty!

Wait. Dead things stop smelling in time. And, as far as I know, even if the (what's left of) the bodies present no "health hazards".

My real experience with a dead mouse (or 2 or 3) was I didn't get to the snap traps in time due to weather. I do have 12 snap traps inside and in the storage areas. They are cheap and do work.

A new RV has all kinds of chemical smells in it. I would try turning the furnace on 85, open all the windows, and go get a meal somewhere. The furnace has an intake inside the unit, so of course you will smell it coming out of the vents.

Bill001 wrote:
Well this brand new RV has something dead in it. Subtle order in the unit if closed up, but comes out of the vents if I turn on the furnance.

I'lve looked into the access panels I have access to. No luck. The return louver to furnace, doesn't show much. Need to get a small mirror to look up this vents.

Any suggestions on finding this thing?

Then you've got a dead mouse in the heating duct work and the only solution is to replace the affected duct work. I speak from experience, having had the same issue myself a few years ago with our KZ Spree. The first time I test started the furnace in the spring the smell was overwhelming :E ... found nests in 2 of the 5 ducts, tried to clean up the mess to no avail, and was only able to fully solve the problem by installing new duct work. I was lucky as the duct work was flexible tubing running above floor through cabinets but if yours is underfloor with an enclosed underbelly you're in for a LOT of work. Has to be done though as pulling each section of duct work for inspection and replacing it is the only way you'll fully resolve the problem.

I would borrow or buy a chimney sweep tool and push it through the vent pipe. It should pick up whatever is in there and move it along to where you could finally reach it.

Had the same problem in a foundation home a good while back (my 34 y.o. son was still a teenager). It started out as a very subtle smell - like someone had cooked broccoli or cauliflower. It finally started smelling like natural gas or a dead animal. Had the son craw all over under the house... found nothing. Had the gas company come out (just my wife was there when they came). A not-so-bright gas company employee used a sniffer and said it wasn't a gas leak but told my wife, "You sure do have a bad smell in your house, lady." I was about at my wit's end when I randomly reached up and pulled a wicker basket down off the top of the frig... it seems that I had thoughtlessly put a 2 lb. package of hamburger up there a week before when I cleared out the freezer to replace the ice-maker. Boy, did I feel stupid!

You might consider the possibility, though, that something crawled up in the underbelly and died. That area and the basement are often used as air return for the heater.

Rob

I found a dead mouse in the Heat exchanger of the furnace. I had the furnace out for a lite and die issue, that turned out to be the gas regulator. Only slightly cooked, no oder had started.

What about a duct cleaning service. Have had the house heating ducts sucked out a couple of times. Was shocked at what was hiding in there. I assume they could do the ducts in your RV. You might have to pull the furnace if they can't work back from the vents.