Furnace issues, smells like something burning.

[Nomadgurl]

I am a new owner of a 2004 cardinal, 36 foot well taken care of by previous owner. Has been stationary at a campground since he bought it. I recently started to use the furnace in the morning or a couple of times during the day to take the chill off, maybe running 10 minutes at a time. I spoke with him before using it at length and had used it probably 2 weeks? The other morning I turned it on when I got up and everything was fine. A couple of hours later I turned it on and it made a noise as I was walking out the door, and I thought that was odd but seemed to run as usual and was outside for no more than 10 minutes but when I walked back inside It smelled like something was burning so I immediately shut it off. I have checked everything and for the life of me cant figure it out. Only things I have noticed are the plastic vents in the floor seemed raised up from their usual flat position. There is a lag time when you turn it off and when the unit actually goes off. The burning smell is only when the unit is on. When I turn it off the burning smell goes away until the unit actually shuts off. Any suggestions?

 

[D W]

A new furnace will often "smell" until the manufacturing oils are burnt off, but this appears to be a 17+ year old furnace? I'd venture to guess you might have a cracked heat exchanger in your furnace. You'll want to have that looked at immediately.

 

[Nomadgurl]

Thanks, the neighbor who helped the original owner pull it out once because a mouse got in there will help me pull it out and check it out. Meanwhile, I have not been using it. And wont.

 

[NavyLCDR]

Thanks, the neighbor who helped the original owner pull it out once because a mouse got in there will help me pull it out and check it out. Meanwhile, I have not been using it. And wont.

The only real source of abnormal noise in the furnace would be the fan/blower. The furnace has two sides (a heat exchanger) - the propane burner side and the air circulation side. If you are smelling a burning smell, it has to be in the air circulation side and could very well be residual particles left in the blower/bearings from the previous mouse attack.

 

[Thomas ho]

i owned a class c , m.h. that smelled when on, it is rust on outside of burner chamber. its common on rvs that are near coastal water. my class c came from florida and bought in upper Texas. i scraped the outside of chamber and it still smelled, so i used a space heating tower max at 13.5 watts. if it was near salty air the water heater inside metal may show rust also. open up the heater box and take a look.

 

[Nomadgurl]

The heater had its own "smell" which the previous owner told me about. The mouse that was in there got into the "squirrel cage'? and was completely removed. The noise it made as I was exiting the rig was like someone kicked the wall and then it sounded like it always does. It is the original furnace that came with the unit. I find it odd that when I shut it off the burn smell goes away until the unit competely shuts itself off ( maybe a minute or 2?) Thank you all for your comments I really appreciate it. Luckily the temps are better and portable electric heater is being used.

 

[MR.M]

The heater had its own "smell" which the previous owner told me about. The mouse that was in there got into the "squirrel cage'? and was completely removed. The noise it made as I was exiting the rig was like someone kicked the wall and then it sounded like it always does. It is the original furnace that came with the unit. I find it odd that when I shut it off the burn smell goes away until the unit competely shuts itself off ( maybe a minute or 2?) Thank you all for your comments I really appreciate it. Luckily the temps are better and portable electric heater is being used.

if it sounded like a bang then the propane did not ignite right away but built up slightly but did lite within the ignition sequence . an adjustment of igniter would be in order and maybe a cleaning of burner . Dust , mouse nests and or mice can get on the heat exchanger and burn and smell .

 

[5picker]

As you can see we are all just giving our best 'guess' answers.
Take that for what it is worth.

There are plenty of past posts with "Mine had this" or "I found this in mine" but we really don't know if they apply to YOU.

Every situation is different and since the smell "could" be something like a cracked heat exchanger that could cause sickness or death, YOUR best bet is to find someone qualified to look at it.

Please let us know what you find.

 

[dmctlc]

Though you mention smell I'm not getting whether it smells like wires burning, spent propane fumes, urine smell, etc..as mention lots of ideas but in the end pulling it and taking a look at it is the best solution though the smell could be coming from something in the vents, again depends on the smell.. Sounds like the neighbor has experience that could be helpful, as well. Being 17 yrs. old might be time for a change.

 

[Nomadgurl]

Thank you all for your answers. The smell is a cross between burning paper and burnt fried chicken, lol. I realize this cant be diagnosed concretely on a forum but the input is always valuable to me and I do appreciate the input. The neighbor who will help will be coming back up in a couple of weeks so I will let you know the results.

 

[RussPastuch]

Dust?

Could just be dust that settled with time. Like starting the house furnace first time in the fall.

 

[MisterVick]

Broken Record - But Mice Are The Devil!

I've come to believe, partially in jest, based on recent personal history that all RV challenges emanate from mice. And I don't care if it's one little tiny mouse, or dozens of the little buggers, it's all "infestation" in my book at least!

But seriously, I'd definitely pull the furnace. If that RV has been sitting you may have gotten mice in the underbelly and if so they probably found their way, as they did in my trailer, into the nice, warm, condominium-style habitat afforded them by your furnace's combustion chamber. Word to the wise, again based on personal experience, if they found your furnace they'll be using your ductwork as their personal interstate system under the floor of your RV. And probably have chewed holes in your ducts as well. But let us hope not, because I spent several weekends over the last few months rebuilding my underbelly and haven't put my trailer back into service yet.

If you find nests check the wiring insulation on the heater, water heater, electrical closet, etc. Through research I learned some forms of wire insulation use soy bean derivatives and when warmed, put off odors reminiscent of salsbury steak dinner to rodents. Their dining habits took my furnace out of service last year when they chewed the insulation off the wiring to a sensor on the back of the burner chamber, and, the insulation off the igniter wire on the other end.

Best of luck with this!

 

[RussPastuch]

"Through research I learned some forms of wire insulation use soy bean derivatives and when warmed, put off odors reminiscent of salsbury steak dinner to rodents. "

And they really love the same soy based plastics used on Christmas lights. I've repaired 4 strings so far in two years.

 

[MisterVick]

Christmas lights too!

Russ: Hadn't thought of Christmas light stringers! They chewed about six inches of insulation off my wires without breaking the conductor, but the unshielded wiring shorted out to the metal chassis of course.

I've gone with nuclear options on mouse prevention since then! My next line of defense, if needed, will be putting strings of LED lights in the underbelly on motion sensors. I've also read the cycles emitted with LED's are a deterent to mice as well. But hoping not to need to go there.

Our trailer moochdocks at a farm much of the time and is unattended, so lots of opportunities for vermin to plot invasion tactics!

 

[Nomadgurl]

Conclusion: It was a mouse sitting on the heat exchanger like a frying pan. Crispy burnt on one side and soft on the other. Thanks everyone for your input, greatly appreciated.

 

[MNtraveler]

For a few extra bucks, Forest River could have installed the model with the automatic flip-over option that also notifies you by Bluetooth when the rodent is fully cooked.

PS: glad you figured that out. How awful! Be sure the whole thing is thoroughly cleaned, and check all the ducts too. You can buy a fairly inexpensive USB "snake" type inspection camera (also seen as borescope or endoscope) and look way up or down into the ductwork. Look for any mouse droppings or anything that looks like nesting material. Then put mouse traps all around your wheels which is how they get from ground to the RV. When stationary, I put out at least 8 (2 by each wheel) and sometimes 12-14 (so there are always some active even if some are "occupied"). You want to trap them outside the RV before they get inside, and don't put traps inside unless you are there to check them every single day.

 

[essarebee]

This is only slightly off-topic. After trying many types of mouse traps I have found one that I feel is the best for me for outside. I've had lots of trouble with squirrels, slugs, crickets, cats, etc. robbing the bait and/or tripping a trap. This one solves that problem and has more points in its favor;
Catch multiple critters
No need to check it daily
No bait needed although I use peanut butter
It is visible if a mouse is caught, you can walk right on by and check
You can release them if you'd rather do that than kill
Easy and clean to take with you on trips, then set them out at home
I'm not affiliated with this product.
https://www.amazon.com/gp/product/B00BGADZ6E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1