Purchased the above RV on March 6, 2024 and having trouble with the furnace. If it's really cold, the temp will increase about 5 degrees, then the furnace shuts off. If it's cool, and the furnace only needs to increase the temp a few degrees, it can do that and exceed the set point by 1 degree, then behaves normally (probably because it didn't overheat). Otherwise, the furnace overheats, shuts off and can only be started again by cycling through from HEAT to OFF to HEAT. I get that it's probably an overheating/limit switch thing, but where to start? Repairs: Home - replace thermostat Dealer (120 mile round trip) replace thermostat(s), something in the junction box. Thought it was fixed (it wasn't - it was too warm to challenge the furnace). 3 days later it got cold and same problem. Back to the dealer - ordered a board and replaced it - thought it was fixed - weather was mild and then it got cold and same problem. We're in touch with Alliance Service, but geez... the hours we've spent trouble shooting is exhausting and we're headed North soon. Ductwork looks fine, no obstructions in the intake/outlets. I'll go look at the vents upstairs one more time to be sure, but I'm at my wits end.
2024 310RL Furnace issues
- Thread starter Katmando
- Start date
Even though the ducting looks ok, you may still have an issue there. It has been noted by others that the installed ducting does not always meet the recommendations. Assuming you have a Suburban heater the specs are attached. Note that it specifically says that ducts terminating in areas such as holding tanks do not count towards the minimum ducting requirements since there is no means for return. Also there have been a number of posts here that discuss ducting issues. I would also point you to the YouTube channel of MyRVWorks. He has a playlist on furnace issues. Good luck!
Thanks - I have no idea how to correct "minimum ducting requirements" but I have a big hammer and I'm about ready to start using it. We saw the new owners of our old trouble free RV drive off with it when we were returning our brand new one for furnace work. We both felt a little sick, wondering if we just made a huge mistake.
BryanValRox
Well-known member
Hi folks, as a fellow 2024 310RL owner, I would suggest that you remove your island duct vents and try to get you cell phone camera down there an take a video shooting towards the front of the coach.
My guess is that you will find the duct work collasped restricting the air flow output causing the furnace to over heat.
My guess is that you will find the duct work collasped restricting the air flow output causing the furnace to over heat.
Been in the same boat.
Update: A new furnace has been ordered and will be delivered to the dealer for installation, but my concern is that the source of problem is in the ductwork and we'll just be repeating this scenario over and over. We're certain that it's an issue with overheating because it works fine if it's not cold. Anything more than an 8 degree difference between the temperature and the set point causes it to shut off. So... question... the picture shows a 90 degree turn in the ductwork going to the bedroom floor vent. The installation instructions from Suburban read, "...avoid making sharp turns..." Would this be considered a sharp enough turn to cause overheating or "cycling on high limit?"
Note: we checked the kitchen island ducts but don't have the proper equipment to determine if there is an issue; airflow seems fine. Air temps at island/bedroom around 120, 90-100 in the bathroom and 200+ at the outlet by the pantry door. This high temp by the pantry door we were told because it was closest to the furnace and should not be an issue.
Note: we checked the kitchen island ducts but don't have the proper equipment to determine if there is an issue; airflow seems fine. Air temps at island/bedroom around 120, 90-100 in the bathroom and 200+ at the outlet by the pantry door. This high temp by the pantry door we were told because it was closest to the furnace and should not be an issue.
BryanValRox
Well-known member
I would not consider that an unreasonable turn. While it is 90 degrees, the duct work isn’t restricted and appears to hold a consistent diameter thru the turn. I would come down on the side of, this is NOT the root cause of your issue.
Would you be able to provide a photo of your pantry door duct? We have a 2024 310 RL as well and do not have any outlet by the pantry.
I'm probably not describing it well. It's on the "coffee cabinet" next to the pantry door. The cabinet that houses the fuse box on the right and some shelving on the left. When you open that cabinet (lower cabinet), below the shelf is a piece of paneling covering what's behind - the duct work. The vent is on the bottom left of the cabinet, blowing out towards the floor, in front of the pantry door and refrigerator? Make sense? If not, I can get a picture. And good! I'm glad that's not an unreasonable turn - I thought the same thing, that there was no constriction that should cause a problem.
Fishfnatic
Well-known member
I have a 24 310 rl and do not have a vent by pantry. Just under kitchen island, bathroom and bedroom. Maybe more of rv standards? Like no outside speakers on my 310. Lol. I also traded in a trouble free camper for mine and lots if things to deal with.
I don't have any solutions for you, but I do have a suggestion on examining the ducts. I bought a small endoscope camera that works with my cell phone. It was pretty fair on pricing, especially considering these things can be $100s. Used it on my 2024 310RL to find the cables to my winegard antenna in the roof since they weren't routed through to the small ceiling cap. It wasn't too expensive and could certainly be useful for other troubleshooting, like looking into your ducts! Here's the link to Amazon for the one I got: https://www.amazon.com/dp/B0C1B47KSS?psc=1&ref=ppx_yo2ov_dt_b_product_details
Hope you get it figured out!
Hope you get it figured out!
UPDATE: New furnace was installed. The dealer called us and said, "Come get it - works perfectly!" We got there early yesterday, indoor temp was 60 degrees so we turned on the furnace, it ran 10 minutes and shut off, never reaching the thermostat set point. In other words, the new furnace made no difference. Neither did the new thermostats, and the PC board. They swear they thoroughly checked the duct work, even installed another to reduce the back pressure off the furnace. The good news is that it works fine in the indoor service bay - the bad news is that it doesn't work when the temps are 60 or below. EVER. So here we are, utterly defeated with a new RV that we've used for 3 out of 50 days. Actually that's WITHOUT a new RV because it's still at the dealers. Another 120 mile round trip for nothing.
I suppose I could if I had it, but I don't. It's still at the dealers and we have no idea if they really do what they say they do. Supposedly they've "checked" all the duct work and "pulled off" some of the ducts. Either way, for them, it always works perfectly, but as soon as we show up, it's the same old story. We're on the phone now with a local RV repair guy and he intuitively seems to realize that 240 degree air coming out of one of the vents is an issue (ya think?) and it's tripping the limit switch. This group isn't associated with a dealership or Alliance, so we'll end up paying out of pocket for something that should be covered under warranty, but at least he seems to understand the problem instantly, over the phone, which is a huge improvement over anything we've done thus far. BTW, the new guy said just what you did - that the furnace should be first tested on the bench, sans ductwork.
It has been my experience with Alliance that you can get work done by mobile techs and they will pay for it - the tech does not have to be associated with an Alliance dealer. You just need to contact Alliance and get approval for the work. I have done this twice with no issue from Alliance - so I would not go out of pocket if you are still under warranty.
Good to know. In retrospect, I wish we had done this. I think we're relying on the dealership too much. Anyway, they have two more days to try to fix it. We're bringing it home Monday. BTW, the communication with Alliance has been fine, that's not my beef other than, given what seem to be well known issues with the ductwork, you would think that would be the first thing to check. Argh... whatever. We look forward to going someplace, someday. This is like buying a new car and having to leave it at the dealership for 8 weeks.
So that's two people here, you and BryanValRox, who don't have a vent on the left side of the coffee stand or whatever it's called that blows air in front of the pantry door. Interesting, because that's where the extremely hot air is coming from. The new repair guy said that over 200 degrees is way too hot (you can't hold your hand in front of it - ranges from 220 to 240) and that most limit switches shut off at 180 or less to prevent a fire. You would think that an extra vent would reduce the back pressure on the furnace, yet this seems to be the source of our problem.
BryanValRox
Well-known member
This is a complete guess, but it would seem that if that amount of hot air is coming from that vent, it would be the path of least resistance. Meaning restricted duct work else where is forcing the majority of the hot air out of that vent.
As I shared before, I would highly recommend inspection of the duct work starting at the island and working back to the heater. I would go as far as requesting pictures from the dealer to prove it is unrestricted.
Given that we don’t have that vent in our coach, it almost feels like someone tried to engineer a easier solution instead of investigation and correction of potential collapsed duct work that would require access from the bottom of the coach.
I offer this a a suspicion only, please keep us posted on the progress.
As I shared before, I would highly recommend inspection of the duct work starting at the island and working back to the heater. I would go as far as requesting pictures from the dealer to prove it is unrestricted.
Given that we don’t have that vent in our coach, it almost feels like someone tried to engineer a easier solution instead of investigation and correction of potential collapsed duct work that would require access from the bottom of the coach.
I offer this a a suspicion only, please keep us posted on the progress.
It's a valid suspicion. We just dropped it off with the new service crew and they seem to be keenly interested in discovering the source of the problem, fully agreeing that it's likely the ductwork. They were a bit gobsmacked at how convoluted it was. Sometime next week I may have an answer.
Clearly this is what needs to happen. Our local guy was not equipped to do this but said the same thing. He removed some excessive duct work and rerouted some ducts. That reduced the one vent from overheating so quickly and redistributed some of the super hot air. Now it takes more time to overheat but note that it still overheats and limits out. The ductwork that he removed was partially flattened, too. We're going to limp along with the fireplace and partial furnace use because we don't want to cancel our trip next week.
We asked the service department at the dealership to check the ductwork, and all we got back was "It's fine." I doubt they accessed it from the bottom of the coach and after many useless trips there at 120 miles a pop, I'm not keen on taking it back to them.
Despite my efforts to stick my head in the sand and wish this would all go away, my husband insisted on trying to identify the problem. Note: nothing has changed after 5 trips to the dealer and one to our local guy. If nothing else, we identified where the north side ductwork goes. Our big question is why are these two runs of ductwork (labeled 1, 2) need to go under the floor and then reappear on the other side of the wall at the same level they originated from? Why didn't they simply run them back straight? And why 2? Presumably, they supply the kitchen island, but that ends in a single outlet with two exterior vent covers on the west and east side of the island. Does one go to the island and the other to where, exactly? As for the 2 inch duct work headed south - we have no idea what that goes to. Maybe to the storage tanks?
All of this is poisoning my brain, obsessing over this @#$%#$% furnace. I like the rest - the big windows, the plumbing, the furniture, fridge, stove, floorplan, bathroom, etc. It's clear that we can't fix it, that the dealer can't fix it, that the local guy can't fix it. It's been 2 months now and the response from Alliance, other than replacing parts that didn't need replacing has been lackluster. "It's important to recreate the problem." Good grief - how many times? We've been recreating the problem since the first day we got it home. We're STILL recreating the problem. That decal on the front door that reads "Warranty for Full-time RVing" irks me every time I open the door. Right... Full-time RVing where the temps never dip below 60 degrees.
What to do? Drive to Elkhart and sit in the parking lot until someone fixes it? We've already driven over 500 miles back and forth to the dealership with no fix - shoot - we could have been nearly to Elkhart by now! Not exactly my idea of a vacation destination, but I'm running out of options here and in a few more weeks, we'll be more worried about AC than heat. I guess there's a Fall trip to Elkhart in the works! Whee.
All of this is poisoning my brain, obsessing over this @#$%#$% furnace. I like the rest - the big windows, the plumbing, the furniture, fridge, stove, floorplan, bathroom, etc. It's clear that we can't fix it, that the dealer can't fix it, that the local guy can't fix it. It's been 2 months now and the response from Alliance, other than replacing parts that didn't need replacing has been lackluster. "It's important to recreate the problem." Good grief - how many times? We've been recreating the problem since the first day we got it home. We're STILL recreating the problem. That decal on the front door that reads "Warranty for Full-time RVing" irks me every time I open the door. Right... Full-time RVing where the temps never dip below 60 degrees.
What to do? Drive to Elkhart and sit in the parking lot until someone fixes it? We've already driven over 500 miles back and forth to the dealership with no fix - shoot - we could have been nearly to Elkhart by now! Not exactly my idea of a vacation destination, but I'm running out of options here and in a few more weeks, we'll be more worried about AC than heat. I guess there's a Fall trip to Elkhart in the works! Whee.
