Furnace doesn't seem to be working

[whisperwhillow]

Once again, we have a 2014 FR, Cherokee Toy Hauler, 377V.

The next thing on my list of things to address for our rig is the furnace. It doesn't seem to be putting out warm air or, shucks, much air at all for that matter. I wind up using the "fireplace" and then an additional smaller heater for the back of the toy hauler where my son sleeps. If I don't use that heater in the back, it gets downright cold back there.

Am I expecting the air from the furnace to be warmer than its capability?
There's at least one vent in the back (toy hauler part) that air comes out of for the A/C. I think the heat may come out of different vents. Is that possible? If so, I don't think there's any air coming out of those vents. I think it's reasonable to assume the gentleman who owned the rig before us had an issue with mice since we found tons of traps in the cupboards, along with excrement (ICK!!). I have cleaned this thing like nobody's business, so I don't think we have any, but I'm guessing it's possible there could be something from them blocking the ducts...?

I'm not sure where to even start; so, once again, your patience is very much appreciated.

[Witch Doctor]

Hate to say it but you are probably overestimating the furnace capability. Sounds like the same problem most units have. Lets start with the furnace air flow. All your duct work will either be 4" round or 2" round. You can't change the heat output. The biggest problem is the way they run the duct work. They either strap it to tight which cuts the air flow down or it just the way they lay it out and sloppy. The only real thing that you can do is try and reroute it, but you would really have to drop the whole belly to do that. The system has two ducts. Your A/C will will be ceiling vents while your Furnace will be either floor vents or low wall vents. Wall vents are mostly only 2" round and most floor vents are 4" round. You can try and close off some vents but I would be careful not to close off more then 25% of the total. You can buy 21/4X10" at lowes or home depot with shut off vents. Then try to force the air where you want it to go. I doubt if you will see a big improvement and can also cause you problems with your limit switch which would shut your furnace off because it can't move enough air. These systems are pitiful to be honest. You stay on an AFB, So I would invest in two 750/1500 watt space heaters and use them. Now with them more then likely You have two sides to your electrical back of the unit and front. Mostly on GFI circuits. Each then would be able to handle 1 heater without tripping the breaker. The most that I think you can do is check the furnace and make sure all the ducts are connected. Look for a sidewall vent in the rear (sons area) If you keep tripping the breaker you can get a 20 amp extension cord and run outside next to your slide out at the bottom and plug it into the 20 amp plug at the pedestal. That would take the load off your breaker panel. Hope that helps you a little. Besides your furnace will drink propane so using electric will be cheaper for you and probably heat better. If your unit has a fireplace use that all the time it is on it's own breaker and shouldn't trip. I use mine and one 1500 watt space heater and stay warm.

[walk_the_walk]

I wrote a long post about this a while ago, after removing, repairing and then re-repairing our Suburban SF-30 furnace. I spent hours and hours on it. The good news is that they are simple units to work on, and the info is readily available online.

The bad news is that, at least on mine, there are 4 wires with no quick disconnects and the wires are cut to length. There is a hard copper elbow connection for the propane and it is hard to get to. I dont recall a propane shut off at the unit, so you have to shut off at the front tanks, run the burners on the stove to get rid of the propane in the lines, then use a crescent wrench.

My suggestion to you is to see if there is anything in the tubes that can be sucked out with a large wet/dry vac, like a mud dobber nest. We have screens covering our ports, and we bought the DINOSAUR ELECTRONICS board for the furnace, but our problem, as the story I posted details, turned out to be a DEFECTIVE exterior dual tank pressure regulator at the front - a $39 part.

So, gas PRESSURE was our issue, and there is no good way to check for this. The stove will work fine on low gas pressure, but the furnace will not.

So, check the ports. Look for a spark from the ignitor. Does the furnace attempt to start up, then fail to stay lit? Does it spark at all?

Your trailer may have come with a manual for your furnace. You will need to read up on your model to figure out things like how many times it will spark before it stops and has to be reset. Usually it is 3-4 attempts and then a long pause, to allow gas fumes to dissipate.

If you are lucky, yours will be a simple fix.

Repairing our Suburban SF-30 - the Agony w/o the Ecstasy - Forest River Forums

[whisperwhillow]

Wow! Great information. Thank you so much.


Now to FIND the furnace... Not really sure where to look. I'll see if I can find some specs online that describe where it might be.

[stantyszka]

Originally Posted by whisperwhillow

Once again, we have a 2014 FR, Cherokee Toy Hauler, 377V.

The next thing on my list of things to address for our rig is the furnace. It doesn't seem to be putting out warm air or, shucks, much air at all for that matter. I wind up using the "fireplace" and then an additional smaller heater for the back of the toy hauler where my son sleeps. If I don't use that heater in the back, it gets downright cold back there.

Am I expecting the air from the furnace to be warmer than its capability?
There's at least one vent in the back (toy hauler part) that air comes out of for the A/C. I think the heat may come out of different vents. Is that possible? If so, I don't think there's any air coming out of those vents. I think it's reasonable to assume the gentleman who owned the rig before us had an issue with mice since we found tons of traps in the cupboards, along with excrement (ICK!!). I have cleaned this thing like nobody's business, so I don't think we have any, but I'm guessing it's possible there could be something from them blocking the ducts...?

I'm not sure where to even start; so, once again, your patience is very much appreciated.

Sooooo......my FR TT had insulation stuffed in the duct work from the factory. When I accepted delivery, I didn't notice this because the coach seemed to be getting down to temp. Only noticed it on a really hot day when the bedroom would not cool down. So my word of advice is to check the ducts to make sure that they are not obstructed with anything. Seems like when they cut the vents in on my trailer, they just pushed them thru and whatever was in its place got jammed into the duct work.

[j free]

walk the walk. x2. they are easy to work on and I have never had them when working properly be able to keep my 5er at what ever temp I wanted. You said they may have had mice you could have clogged vent tubing from mice nest. Try a wet/dry vac and clean them out.

[bob caldwell]

Remember....the factory flex ducting is very thin walled...be careful pok'n around with a vacumn.

[BobHanke]

You might also run the fan in your A/C unit on low to circulate the warmth you have. We find this most helpful when using an electric space heater. Also make sure your furnace is getting 12V DC as it needs that for ignition.

[Witch Doctor]

Originally Posted by whisperwhillow

Wow! Great information. Thank you so much.


Now to FIND the furnace... Not really sure where to look. I'll see if I can find some specs online that describe where it might be.

Look around on the outside of the unit will see a vent cover with 2 round holes in it maybe 3"x8" rect. That is your intake and exhaust. Your furnace should be on the other side of that. ...Good Luck, you can do it.

[Blackhat6mike]

My furnace didn't even have two of the vent tubes attached, they were just laying there beside two open holes in the heat distribution box. I reconnected the two vent tubes, closed off the two extra unused ports and it now blows plenty of air. Nice and warm too.
X2 on the super thin walls of the vent tubes. Anything that touches them will put a hole in them. I've given thought to replacing them with thin walled 4" PVC like I did in our sailboat, but it will take a lot of work.

[oldtool2]

Originally Posted by bob caldwell

Remember....the factory flex ducting is very thin walled...be careful pok'n around with a vacumn.

I agree. I wouldn't use a large shop vac hose. Use a small hose from a household tank cac. Much safer. And do each register separately.

"There's at least one vent in the back (toy hauler part) that air comes out of for the A/C. I think the heat may come out of different vents. Is that possible?" Yes, your heat should be coming out of the rectangular floor vents. AC and heat are separate. The AC are normally round and in the ceiling.

Jim

[Dabmeb]

When I checked my furnace the back panel had fallen off. All the heat as being dumped under our bed.

[whisperwhillow]

Oh, wow, dabmeb! That's crazy!

Sure wish I could post photos. I'd love to post some photos to get y'all's input on if some different vents are actual ventilation or access.

[Dabmeb]

Ours went back to the dealer for almost no air flow in the kitchen and living room. The dealer said it was a disconnected hose under the shower. When they were done it was a little better but not great. I pulled the trim panels off around the furnace and the entire rear panel fell down. One screw was missing and one clip had broken.

[Myrle]

Still digging pieces of Styrofoam out of ducts after 2 yrs.

[whisperwhillow]

My goodness, Dabmeb! What the heck...

Wow, Myrle. That's disheartening, but glad you're finding it at least.

So, the coldest area in the RV is in the actual toy hauler part -- the very back. I only see one cent back there that appears to be for heat. It's circular and down by the floor. Unfortunately, it's right behind the washer/dryer, so circulation may be an issue, but I can at least deal with that when I figure out why no air is coming out. I pulled off the panel under the lavatory behind the vent and saw no issues there -- it was connected to the vent, and I saw no holes. I pulled the face off of the vent and saw what appeared to be a lot of vermin excrement. I put the vacuum cleaner hose in the see if I could get something like a nest, or something similar, but got nothing. Tomorrow I'll try to find where the hose might be going next.

[oldtool2]

Originally Posted by whisperwhillow

My goodness, Dabmeb! What the heck...

Wow, Myrle. That's disheartening, but glad you're finding it at least.

So, the coldest area in the RV is in the actual toy hauler part -- the very back. I only see one cent back there that appears to be for heat. It's circular and down by the floor. Unfortunately, it's right behind the washer/dryer, so circulation may be an issue, but I can at least deal with that when I figure out why no air is coming out. I pulled off the panel under the lavatory behind the vent and saw no issues there -- it was connected to the vent, and I saw no holes. I pulled the face off of the vent and saw what appeared to be a lot of vermin excrement. I put the vacuum cleaner hose in the see if I could get something like a nest, or something similar, but got nothing. Tomorrow I'll try to find where the hose might be going next.

"circular and down by the floor. Unfortunately, it's right behind the washer/dryer"

Are you sure that is not for a drier vent?

Jim

[whisperwhillow]

Yes, Jim, I'm sure it's not a dryer vent. One, it has the same face as the vent in the bedroom; two, it has ducting going through the wall and under the sink behind it; and three, there is no outlet to the exterior of the RV for the dryer lint. No warm air coming out of it, though -- no air at all actually. No air coming out of the two floor vents in the kitchen/living area either, but the vents are warm to the touch when the furnace is on. Nice, warm air out of the vent in the bedroom, though.

[Witch Doctor]

Whisperwhillow, why can't you post pictures? Do you have a phone that takes pictures or do you have camera that you use to download to your computer? With either of them we can get you through posting? If you have good air in the bedroom Block that register off and see if you get air at any other. Where is your furnace located in the belly of the trailer? When you open your storage area under the floor is it hot down there by any chance when the furnace is on?

[bob caldwell]

My vote is for torn hoses.