Jump to content
Sign in to follow this  
routlaw

Suburban Furnace acting very erratic

Recommended Posts

Hoping someone can shed some light on a Suburban Furnace that is not working most of the time, or at best being very erratic. I have been so busy these last couple of years I've had very little time to get out in our Oliver, but this happened earlier while up in Glacier NP with terrible weather, then again in the Beartooths this past weekend, also very cold at night with the need of heat.

 

Briefly this is what happens, turn furnace on the fan runs for approximately 15 or 20 seconds but the furnace does not seem to ignite the whole thing quits. Turn the switch off, than back on again same thing over and over. Last night I did this exercise some 15 or so times all to no avail. The previous night it worked. Now here is where it gets really odd. Broke camp drove down the road a ways into Red Lodge pulled over to the curb, went back to the camper furnace works. The trailer was way out of level, went down the road another mile or so, did the same thing and furnace works again. In frustration drove home unhitched, turned on furnace and it works again. However I just don't trust the thing anymore at this point.

 

At all times the camper was level, fuel bottles full and all other gas appliances, fridge, cooktop and hot water heater all worked perfectly, and checked fuses all good.

 

Does anyone have any clues what so ever that might be causing this.

Share this post


Link to post
Share on other sites

Hey Routlaw,

 

All of my electrical issues have been with bad connections so I would start there. Oliver really should be using adhesive lined heat shrink connectors, given the nature of the environment these connectors live in, ie, moisture, dust, vibration. But alas. The 12v supply wire to my furnace had bare wire sticking out of one end of the crimp connectors.... So check to be sure all are tight, tape any bare wire with electrical tape to avoid potential shorting.  Also check the frame ground, which is a female spade connector (it's attached to back of furnace, closest to exterior wall in the center). Since your furnace works intermittently, that suggests to me that there is a bad connection somewhere. The piezo igniter should also be checked, but can't tell you offhand where that is, I'll have to go and look. I'd give Jason a call and see what he says. I'm no electrician, but these have been my experiences.

 

Dave

 

ps: I'd also pull out the thermostat and check the connections on that end as well.


2015 Oliver Elite, Hull 107


1998 Ford E-250, 5.4 liter

Share this post


Link to post
Share on other sites

Thanks Dave for the input. How on earth did you expose any connections without taking the entire enchilada out of the camper. On mine I have no access whatsoever that I can see. There is a group of wires going into the back side but no exposed connectors at all that I can see. I will add though at all times the fan motor will turn, but the erratic part is the ignitor not lighting.

 

After posting this initial call for help a quick internet search shows that these furnaces are notorious for this issue of erratic behavior. Often the problem is a "sail switch", sometimes an incorrect setting for the solenoid valve, then a heat overload switch and last but not least is debris, insects and other creatures building next and obstructing the ports.

 

If I'm not mistaken Oliver has gone to a different furnace, perhaps because many have had issues with these as well. The thought of taking the darn thing out is a bit daunting.

Share this post


Link to post
Share on other sites

I don't think you can do much of anything to this furnace with it in situ, you cannot even snake a borescope inside the exterior openings enough to see anything but dirt. Pulling the unit out should not be hard tho I have never attempted it. This might help, a little... you can inspect the flame, if it actually lights, and remove the ignitor lead and the ignitor itself. Once out, you can perhaps see inside the can with a scope to see if there is a nest in there.

 

https://olivertraveltrailers.com/topic/how-to-service-your-furnace/

 

Keep in mind that circuit board problems are very common with all these cheap RV appliances, yours may be toast.

 

Good luck, and please start a new thread if you remove it, with pics, to help other owners.

 

John Davies

 

Spokane WA


"Mouse":  2017 Legacy Elite II NARV (Not An RV) Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/

 

Tow Vehicle: 2013 Land Cruiser 200, 33" LT tires, airbags.

Share this post


Link to post
Share on other sites

Hmm. On my Elite1, the furnace is under the front dinette seat. All the electrical connections are on top of the unit. Don't know about the Elite2.

 

Definitely give Jason a call. If the fan turns on before the igniter tries to light the burner, as it should, then perhaps your Tstat is OK. Hopefully someone else will chime in with more ideas. Good luck.

 

Dave


2015 Oliver Elite, Hull 107


1998 Ford E-250, 5.4 liter

Share this post


Link to post
Share on other sites

@ Dave, yeah the Elite II's are located behind the hot water heater on the curb side, in what can only be described as an extremely difficult access. I agree I don't think my Tstat is toast, pretty sure its something at the actual heater unit.

 

Thanks

Share this post


Link to post
Share on other sites
I don’t think you can do much of anything to this furnace with it in situ, you cannot even snake a borescope inside the exterior openings enough to see anything but dirt. Pulling the unit out should not be hard tho I have never attempted it. This might help, a little… you can inspect the flame, if it actually lights, and remove the ignitor lead and the ignitor itself. Once out, you can perhaps see inside the can with a scope to see if there is a nest in there.

 

https://olivertraveltrailers.com/topic/how-to-service-your-furnace/

 

Keep in mind that circuit board problems are very common with all these cheap RV appliances, yours may be toast.

 

Good luck, and please start a new thread if you remove it, with pics, to help other owners.

 

John Davies

 

Spokane WA

 

John this is great information, thanks for posting all this, very helpful. The way you accessed this was exactly what I had perceived what one had to do.

 

What I don't understand is why Oliver did not create a situation that made servicing these things easier. My guess is, the furnace was installed in the bottom exterior tub before the interior tub was mounted making it nearly impossible to extricate the thing out of its original installation. The least they could have done was provide a larger access to those two screws at the back plate. Not trying to rag on Oliver but this really is a poor design situation for future service.

 

Regardless I agree in order to work on this thing they have to be taken completely out, no small task. There is an on off switch where the wires enter the chamber which I turned on and off a several clicks hoping that might just clean up a contact an make for an easy fix. In the meantime I have a service request into the folks at Oliver on what I should be doing next. I will run the furnace tonight to see how things go, but suspect an exorcism is on my agenda.

Share this post


Link to post
Share on other sites

Routlaw,

 

Check out this video, very informative. I think all you have to do for access is remove the exterior cover. The exhaust port tube slip fits into the furnace inside so just slide it out gently, then remove the large cover. But verify with Jason first!! I've not opened mine up all the way like this yet.

 

 

Check out the LED flashing on the board, the codes are in the manual you should have gotten from Oliver:

1 flash w/3 second pause: limit switch, airflow problems

2 flashes w/ 3 second pause: flame sense fault

3 flashes w/ 3 second pause: Ignition lockout fault

 

Dave

 

 

  • Thanks 1

2015 Oliver Elite, Hull 107


1998 Ford E-250, 5.4 liter

Share this post


Link to post
Share on other sites

Dave, thanks so much for that video link, I am going to add it to my thread on servicing the furnace.

 

John Davies

 

Spokane WA

  • Thanks 1

"Mouse":  2017 Legacy Elite II NARV (Not An RV) Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/

 

Tow Vehicle: 2013 Land Cruiser 200, 33" LT tires, airbags.

Share this post


Link to post
Share on other sites

My first thought is the sail switch has some fibers or hair stuck to it.  I was going to pop the cover off and take a picture of the location for you, but there are eight screws holding the cover on and it’ll be dark before I find the tools get it apart.

 

My furnace was acting similar this March while camping in Moab, Utah. After an internet search I took out the sail switch in the campground (while it was snowing) and found a few long fibers hanging off of it. Pulled the fibers off, reinstalled, and the furnace fired back up. I found that it takes VERY little interference to affect the proper operation of this microswitch.

 

Pull the cover, look for two wires leading to the back of a micro switch.  I think it’s on the lower left side looking in at the furnace from the outside.  Remove the micro switch with its long metal operating arm and clean it off. Make sure it’s switching smoothly.  Be careful removing and replacing so you don’t bend the sail part

 

Good luck. HTH. Ken.


2013 Toyota Land Cruiser 200


Twin Bed Elite II #351

Share this post


Link to post
Share on other sites
Dave, thanks so much for that video link, I am going to add it to my thread on servicing the furnace.

No problem John. I was happy to stumble across it. Very well presented and informative I thought.

There's a lot to learn maintaining our trailers!

 

Dave

 

 

  • Thanks 1

2015 Oliver Elite, Hull 107


1998 Ford E-250, 5.4 liter

Share this post


Link to post
Share on other sites

Just heard back from Jason this morning, he felt it was most likely the sail switch too. FWIW, the furnace fired up this morning with no problem, but I just don't trust it until I can get in there and see whats going on. Thanks Dave for this video I will take a look at it shortly. I do have those manual papers but their instructions are not very explicit for removal IMO. Need to check the codes too.

 

@ Ken, congratulations on pulling this off while in a campground. Well done!

Share this post


Link to post
Share on other sites

I've heard back from Jason and thought I would share what he has had to say thus far about working on the Suburban furnaces, should anyone else run across a similar problem with same furnace.

"The exterior exhaust should be riveted in place. The furnace has some mounting screws to hold it to the aluminum bracket inside the camper. The furnace itself once loose has to be removed either through the basement or through the above access panel if you can maneuver it."

So effectively those ports are not coming out without some serious destruction, and getting this beast out is not going to be easy which we all knew anyway. In the meantime this furnace has now started up every time I've tried this morning and appears to have blue flames although access to the peep hole is minimal at best and getting a good iPhone photo just about as easy.

I've not been able to identify the sail switch with multiple attempts at iPhone photos from inside the furnace.

@ Ken, by now I have to assume you have the Atwood furnace and not the Suburban as there is no cover to remove on the Suburban which is a complete total encasement.

Thanks Rob

Share this post


Link to post
Share on other sites

This doesn't look right to me, only one wire hooked up to the thermostat. Normally as prescribed by Suburban there should be two wires running from the thermostat to the two blue wires supplied by Suburban. Oddly enough though there are no pink wires at the Tstat, but one red wire. So how could this furnace have ever worked in the first place?

 

Photo below:

 

IMG_1110.thumb.jpg.87020ce78ea92b361e684b5233a84cf5.jpg

Share this post


Link to post
Share on other sites

That looks suspicious, but from what little I know of Dometic thermostat wiring, it isn't intuitive and it varies among different models and combinations of thermostats and A/C units.

 

Also, photos of Oliver electrical connections make me angry.


Snowball • LE2 256 • 2018 Ford Raptor

Share this post


Link to post
Share on other sites

Agreed Overland. I was on the phone for quite awhile this afternoon with the Suburban tech support people which were very helpful. Understand this is not a Dometic, it states RV Comfort HP on the Tstat, but what is odd is there is no pink wire at the Tstat, however there is a reddish brown which as you can see on this photo is NOT connected.

 

This episode just gets weirder by the hour. We can't remove the furnace from the camper either as there seems to be a hidden screw in the casing toward the bottom front near exterior wall that has been attached to the forward support bridge. I'm not making this up. How on earth any installer was able to do this is behind me. Next option is to try and extricate the heat exchanger assembly from the casing. That ought to be fun.

 

Thanks

Share this post


Link to post
Share on other sites

So it may not apply to your situation then, but I believe that on the models with the newer Dometic thermostats and A/C units, the furnace wire actually goes to a control board in the A/C unit and then another wire (usually a data cable, but that depends on the model) goes from the A/C to the thermostat.


Snowball • LE2 256 • 2018 Ford Raptor

Share this post


Link to post
Share on other sites

But surely even with this odd configuration there would still be at least both Tstat wires for the furnace connected to two wires from the Oliver?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...