How do I operate my furnace? - A major learning experience!

Rickf1985 · April 04, 2016, 04:11 PM

You people type too fast! If you take the whole unit out then you will have a big opening in the side of the RV and if you have help you can have someone at the propane bottle open and close the bottle and see if you get gas from the line. You will hear it right away as soon as the bottle is opened. If not then you have some detective work to do. If you decide to check it that way be sure the fridge and water heater are off and nobody is smoking. With the door open and the hole in the side the gas will disperse quickly. Every time I get my tank filled I am amazed at the amount of liquid propane that is escaping from the spitter when they are filling the tank.

SLEETH · April 04, 2016, 04:46 PM

yep them 80% valves do spit out a lot of liquid

LJ-TJ · April 04, 2016, 05:53 PM

I'll put my money on it being a gas fuel line for your genny. He just came up with a scathingly brilliant idea. Take the gas cap off your fuel tank. Open the valve to no ware and blow in it. If you here bubbles in the gas tank it will answer our questions. D:oH!

Rickf1985 · April 04, 2016, 07:13 PM

Or turn the gas on and open it and see if propane comes out, only if it is in an outdoor compartment. If it does then follow it back to the source and remove that line and cap it with the proper cap, that valve, if on a propane line is dangerous.

kansascat · April 05, 2016, 12:59 AM

Most of those older suburban furnaces can be easily removed. The metal enclosure stays in place. Remove the LP line where it attaches to the actual furnace. Unplug the wires on the side, and remove the screw or screws inside at the bottom next to the heat exchanger that screw into the floor going thru the metal enclosure cabinet. Then they have a hidden screw that goes thru the very dead center of the exhaust outlet opening on the outside of the coach. It secures the furnace exhaust to the outside exhaust cover holding them securly together so there is no leakage at the wall. Then the units interals should slid straight out into the RV.

perlgurl · April 05, 2016, 05:00 PM

Thanks so much for these instructions!

I've got the furnace out (although the whole thing came out since the metal frame was not attached to the floor!)

I did smell a touch of propane with I disconnected the copper tubing, (yes, the propane was OFF but I imagine a tiny bit stays in the tubes until it is released. )

I also can't seem to get the furnace out of the metal frame, not matter how much I try. But I've managed to get a lot of dirt and rust out from inside the furnace, used the shop vac to both suck as much dirt out and then blow the rest of the cobwebs out.

I do think my first problem is the pilot hole. I've disconnected it and tried to gently blow through it but nothing is coming out. I'm wondering if I can just replace the part or if I dare trying to clean it.

Also, it seems there is a small motor on the back of the furnace (which is what the wires were for I suppose). Can someone give me the Dummies Guide to how this works? It seems like it is wired to the thermostat, but does the battery on the vehicle need to be on in order for it to work?

Side note: I currently just have one battery in the RV with a master cut off switch in use since something was draining the battery when I don't disconnect it). There is room for a second battery, but the positive wire is missing so I have not got around to hooking a second one up. (wiring is a mess on this thing!)

LJ-TJ · April 05, 2016, 07:04 PM

WOW great looking furnace. I'm going to bow out as there are folks here more versed at this particular furnace. Good luck. Looks like you got a nice furnace to work with.

perlgurl · April 05, 2016, 07:41 PM

I have FLAME! However it's not actually pumping out heat even with the thermostat cranked way up high and I'm not hearing the motor in the back of the unit turn on so I suspect a wiring/power issue.

But FLAME! I did this. With your help! Thanks!!!

I also found the reset button cover when I cleaned out the furnace, so that's a bonus too.

M & J · April 05, 2016, 08:34 PM

Congratulations ma'am. RV furnaces have a safety feature that insures the blower fan is running before the main gas valve is opened. It's called a sail switch and moves from the air from the fan. It's backwards from our home gas heaters. Your next step will be to make sure you have 12v going to the furnace then checking for your fan running. Lots of threads on sail switches.

Rickf1985 · April 05, 2016, 09:58 PM

Make sure you check all the connections with soapy water, disturbing them could have caused a leak that is better found now.

perlgurl · April 05, 2016, 10:12 PM

Quote from: M & J on April 05, 2016, 08:34 PM
Congratulations ma'am. RV furnaces have a safety feature that insures the blower fan is running before the main gas valve is opened. It's called a sail switch and moves from the air from the fan. It's backwards from our home gas heaters. Your next step will be to make sure you have 12v going to the furnace then checking for your fan running. Lots of threads on sail switches.

I already started to watch on video on sail switches, neat that I was on the right path without even knowing it!

I hear the thermostat click like it's trying to engage. I've also put the wires back together correctly, I think; I took a photo before disconnecting them, but realized as I was putting them back together that there were two blue wires coming out of the furnace that should connect to a red/blue pair but I didn't mark which blue from furnace was "red" and which was "blue", but I think I've got the right set together at this point.

I'm still learning how to make the RV run on battery and will eventually have to figure out how to hook up the generator, with the "city plug-in" method being the least likely thing for me to use.

I'm done for the day. Propane is off and the RV battery is disconnected. I'll got other stuff to work on tomorrow so I'll try again in a couple days.

perlgurl · April 05, 2016, 10:12 PM

Quote from: Rickf1985 on April 05, 2016, 09:58 PM

Make sure you check all the connections with soapy water, disturbing them could have caused a leak that is better found now.

I plan to do this as part of the final "button up" once I get everything running for sure.

yellowrecve · April 05, 2016, 10:58 PM

Both blue wires do the same thing. So your OK. They're for the wall thermo.

TerryH · April 05, 2016, 11:34 PM

A bit off topic here, but while you are working on your furnace you may want to consider upgrading to a digital thermostat.
Easy to switch over, far more accurate, display high, low and ambient temperatures and you can actually see when the furnace fan is about to cut in prior to fire box ignition.
One reference to them below. There are others here as well.

http://www.classicwinnebagos.com/forum/index.php/topic,9026.msg49094.html#msg49094

LJ-TJ · April 06, 2016, 11:31 AM

Well once your happy with the furnace start a new thread on Batteries and we'll try hand give you a hand hooking them up. Just remember we like pictures. Oh! did you figure out what that extra copper line was for. Some thought a fuel line some though propane? Hm?

perlgurl · April 06, 2016, 02:27 PM

Quote from: TerryH on April 05, 2016, 11:34 PM
A bit off topic here, but while you are working on your furnace you may want to consider upgrading to a digital thermostat.
Easy to switch over, far more accurate, display high, low and ambient temperatures and you can actually see when the furnace fan is about to cut in prior to fire box ignition.
One reference to them below. There are others here as well.

http://www.classicwinnebagos.com/forum/index.php/topic,9026.msg49094.html#msg49094

TerryH, thanks, I like this idea very much!

I noticed yesterday that the thermostat appears to be original and since that is over 40 years old, I think upgrading to a new digital one once I ensure the furnace works (don't want to throw another monkey into the mess I'm trying to sort out) is a really great idea. Other stuff to work on today, but I'll plan to get back to it tomorrow.....

LJ-TJ · April 06, 2016, 02:32 PM

Hey Kiddo remember KISS. Stay with the old try and trued. Like you said get everything working first. You can always change it up later. You doing a great job.

perlgurl · April 06, 2016, 06:08 PM

Quote from: yellowrecve on April 05, 2016, 10:58 PM
Both blue wires do the same thing. So your OK. They're for the wall thermo.

This is SUPER NICE to hear. One less thing for me to worry about tomorrow when I try to get the blower motor thing to actually work.....

brians1969 · April 06, 2016, 08:00 PM

Your propane hoses look original and one is retained with a hose clamp. It would be a real good idea to change them. The Suburban heat exchangers are thin sheet metal. With the age of that furnace, if the exchanger leaks, you will have carbon monoxide coming into living space. At the very least, I would recommend a CO detector.

perlgurl · April 06, 2016, 09:34 PM

First of all, thanks to everyone so much for all the tips and encouragement! I'd call this my second project (trying to get a older motorcycle running in an attempt to learn how motorcycles work, since I ride them) and though I'm a bit late at learning mechanical stuff, I'm finding it enjoyable and I can say without a doubt that all your help really makes a big difference in my success rate!

I've being doing a bit more research in preparation for working on this again tomorrow and I'm wondering what the easiest way to ensure I actually have power to the rig?

I think "shore power" (what they call using the plug to city power, right?) would be the easier way to test; then I can look into get the battery and / or generator power working. I've been in a mindset of trying to make it work for boon-docking since that is how I'll be using it more times than not, but maybe that is complicating my attempts to see if the furnace is even getting electricity.

So, maybe I should run an extension cord to the RV and use that coupled with the propane and see what happens for testing the furnace again tomorrow? What do you think?

LJ-TJ · April 06, 2016, 09:58 PM

Yep! Your right. When folks talk of shore power they are talking about regular house to motor home electric.(Extension cord) If you can get a picture of your converter and also your battery bay so we can see what your contending with. Hm? Your doing great kiddo.

M & J · April 06, 2016, 10:14 PM

And, start a new thread on shore power to keep posting guidelines in place.

We had another lady member - moonlitcoyote who was as tenacious as you. She wasn't afraid to raise her hand for help and equally unafraid to tear in to something to get it fixed.

DaveVA78Chieftain · April 06, 2016, 10:33 PM

It might help if you download the manual for this suburban pilot model furnace from our member section. It is the 1970 Dyna-Trail NT Series (Installation, operation, service, diagnosis & repair and parts list for NT series 20A-AD, 22A-AD-CS-CDS & 30A-AD-CS-CDS).
It includes parts descriptions as well as sequence of operation.

The flame you got going is the pilot light. The fan has to be running to operate the sail switch then the main gas valve.

Anatomy of an RV Pilot Model Furnace

perlgurl · April 06, 2016, 10:40 PM

Quote from: M & J on April 06, 2016, 10:14 PM
And, start a new thread on shore power to keep posting guidelines in place.

We had another lady member - moonlitcoyote who was as tenacious as you. She wasn't afraid to raise her hand for help and equally unafraid to tear in to something to get it fixed.

I've started another for power. thread: http://www.classicwinnebagos.com/forum/index.php/topic,12391.msg73332.html#msg73332

M & J · April 06, 2016, 10:45 PM

Yup. What Dave said.