Suburban Furnace issue 2014 View Profile 24G

[redbaron]

My Suburban Furnace blow warm air only
Any advice and Ideas are welcome
George

2014 Winnebago View Profile 24 G
Suburban Furnace Model # SF 20 QW

[Eagle5]

Hi George,
Below is an RV Technician working upon a SF-20 Suburban Furnace.
I hope this helps!
Eagle5

SF-20 Suburban Furnace

[Morich]

More info on what the furnace does when starting will help a lot.
When you turn the thermostat to heat and turn it up, does the blower start?
After it starts and runs a minute or so, does the fire light?

If the fire is burning and the blower running, it should get warm air. But there are times when the furnace ductwork comes apart and you may get a mix of warm with a lot of cold air.

So we need to know more about what is happening to know to look at why the furnace is not working right and burning or if the ductwork is letting cold air in someplace!

[redbaron]

Hi Richard Everything is working fine exhaust is hot but inside vents only warm air all ducting is ok no bend or obstruction the bathroom vent gets warmer then the rest of the vents .will start up furnace as soon as I get a change I will take measurements with my heat gun and report back to you with my findings.
As always thanks for your time and help
George

[Morich]

If the fire is coming on and staying on as long as the thermostat is calling for heat, I'm short on any ideas of why it would not be warm enough.
There are a couple points that I know can mess it up even with the fire burning right but they are kind of odd things.

If there is something in the path where air is pulled in through the section that gets hot and enough to slow or stop the air flow, it usually shows up as not burning or going out, so I would not guess that.
But the fu4rnace on RV are kind of like a blowtorch in a barrel with the inside air just passing over and around the barrel, so there isn't too much really hard stuff if the fire is burning right.

There is a limiter switch that can go bad and make the fire go out before it should. It's meant as a safety thing so that if the furnace metal and around it gets so hot it might cause a fire, it shuts off the furnace. But that doesn't sound right when you say it is not warm enough. The fire would go out and just stop! Not warm, just dead!

I got a picture of where the warm ducts run, just for ideas but if they seem to all be getting near the same amount of air, that may not be any help.
The longer may be a bit cooler if the air has to travel further but not after it gets them all warmed as it runs. You've got one that is quite a bit longer and might take a minute or so longer to get it warmed up?


I was thinking one might have fallen off the duct connection but flex duct will not have very many connections along the way.

If the fire is coming on and staying on as long as the thermostat is calling for heat, I don't think of any real way to change the amount of heat.
No adjustments I think of but just fire on until the thermostat tells it to go off!
If it was coming on and going off too soon and then starting again, it might be things on the furnace controls or thermostat??

[Sadie Camp]

Had similar problem in my 2014 Sightseer. Researched and found behind the return air vent the manufacture did not cut the plastic underlayment out of the hole to the return air side. The furnace was choked off. I cut the plastic away so it can get return air and it works perfectly now. Hot air in all vents. Pull the return air vent and check it out.

[Eagle5]

Greetings Sadie Camp,
As both you and redbaron have the same 2014 model year, it seems likely you have identified the fix to the problem. Thank you for letting us know, and welcome to the forum.
Eagle5

[Morich]

Hard to believe an RV would be on the road for nine years and nobody noticed the furnace did not blow???
I guess some folks are more tolerant than others! Maybe they never camped and needed the heat?

There is one thing that I find common on furnace if the vents are not covered. Wasps seem to follow me around and try to get even!
If they get in the two ports where cumbustion air goes in and comes out the outlet, they can build a nest to stop the air flow. It should stop the airflow and keep the fire from lighting but running a wire in to bang around those vents may find a nest in there?
No wires, switches or anything in there to get messed up, so maybe a quick thing?

The fire should be burning pretty well fully inside that chamber so maybe look for signs the heat is not burning as far in as it should? The paper labels and stuff in the outside door should not be getting scorched!

[Eagle5]

I bought one of these scopes just for situations like this:
SKYBASIC Industrial Endoscope Borescope Camera with Light
Sure is handy now and then, and $30 isn't too expensive.
Eagle5

[Morich]

Originally Posted by Eagle5

I bought one of these scopes just for situations like this:
SKYBASIC Industrial Endoscope Borescope Camera with Light
Sure is handy now and then, and $30 isn't too expensive.
Eagle5
Attachment 187921

Good idea for looking places we can't see and I keep thinking of things I might use something of the type but still not done it!
I'm trying to quit working!

So can we sort some questions?
I see the probe as super small but how much or how wide is the view you get? How do you force it to go where you want and turn the right way? Chasing down an open pipe it has to go one way but if in an open space, do you have much trouble going in and then turning right or left, etc to see an exact spot like a leak?

Bend a stiff wire attached to the head and hope to get it aimed?

[Eagle5]

Hi Richard,
It is not the perfect panacea, but you can rotate the screen and cable and guide it into where you wish to visualize. As I do not use a Smart Phone, this thing was the right choice for my occasional use. They do make models which are designed to display on a Smart Phone, but I don't think they are significantly cheaper.
Thanks, Eagle5

[wahoonc]

I have used a variety of these over the years. The original ones were over $200 and had a 2" screen mounted on a pistol grip handle. The last one I purchased is similar to this one. Mine uses WiFi and works via an app on my cellphone or tablet. You can save pictures or video from your explorations. The camera light is adjustable, it is in a stiff wire that you can move around to get where you need to go. Mine was in the $35 price range. It has paid for itself many times over. It and my multi-meter are probably my most used tools.

Aaron