Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-16-2008, 02:47 PM   #15
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,814
Images: 12
Quote:
Originally Posted by HowieE View Post
Before getting into the electronics check one thing. I have found that if my gas system has been opened and gas pressure relieved in the lines that the heater will not come on because of air in the lines. What I have done to correct this is brake the gas connection at the heater just until you smell gas. This insures you have gas not air at the heater. Then tighten the connection and cycle the heater.

If everything is working the fan should come on for about 15 to 20 seconds and then you should hear the gas solenoid click and the heater start to put out heat.

The reason for this problem of air in the lines is the fact that the pilot valve in the heater is so small that it can not purge the air in the lines in the time allowed for proof of pilot flame and thus denies turn on.
Well it is a good thing I just posted this solution because I had no heat Friday night and had to get it fixed ASAP because it was cold. Had to brake the gas line connection Saturday am to purge the air from the line and then the heater worked fine.

If you want to tare into the heater before verifying that you have gas at the heater have at it but I have found that cars, trucks, and heaters need gas before all else.
__________________

__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 11-17-2008, 08:57 AM   #16
4 Rivet Member
 
Pacerized's Avatar
 
1981 25' Excella II
Dillon , Colorado
Join Date: Jul 2006
Posts: 397
Images: 11
Just a quick update on my project. After I posted the first thread where as my furnace had stopped working on our last trip to Moab winter set in quickly here in the mountains. My time is very limited due to work so I had to stop working on the furnace and quickly winterize the Airstream. We were then given a nice reprieve in the temperature so I decided I'd better spend the time I needed to in staining my house and coating my driveway before the real snow started.
Back to the Airstream, I determined that I wasn't getting a spark by listening and trying my multimeter so I replaced the starter with diode since it was cheap. I only hear the blower motor start and then nothing else. This wasn't the problem so I started to take off the gas line as suggested but found it to be a very difficult task. I've given as much torque as I feel comfortable with and just can't get the line to break loose. Any more and I'm sure I'll just break the line. I've been trying to work on the furnace without pulling it out but may need to do so after all.
Everything that is in line after the furnace lights fine with the gas. Wouldn't that rule out a lack of fuel at the furnace?
I haven't been able to locate the sail switch. Could someone tell me where this is usually located? I thought I'd start with that and then test everything that I can with my multimeter starting with the limit switch.

Thanks: Charlie
__________________

__________________
Pacerized is offline   Reply With Quote
Old 11-17-2008, 09:55 AM   #17
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,814
Images: 12
The sail switch is buried deep inside by the fan. You have to remove the Sub to get to it.

Yes a flared fitting can be hard to brake free. If you can get a wrench on the flare nut and one on the shut off valve you will be able to open thet connection.

Like I mentioned above I have to open mine Saturday am.

I don't know of any other way to purge the gas line to prove that you have gas at the burner.
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 11-17-2008, 10:29 AM   #18
Just a member
 
thenewkid64's Avatar
 
1978 28' Argosy 28
Tampa Bay , Florida
Join Date: Mar 2002
Posts: 4,539
Images: 21
Send a message via AIM to thenewkid64 Send a message via Yahoo to thenewkid64 Send a message via Skype™ to thenewkid64
I had to replace the sail switch in mine years ago, it has to come out to do it.

So you have fan, but no second click?

The order of operation is:

Relay click , Blower motor start

Sail switch closes

Gas valve opens (audible click)

Ignition (audible clicking)

Heat!


So if the sail switch is bad, the furnace will never light. If you have gas at the appliances down stream, I doubt gas is the issue. Do you hear the clicks as outlined above? If not the sail switch is the logical culprit, and while it is a PIA to replace it is less than 20 bucks to get...
__________________
Brett G
WBCCI #5501 AIR # 49
-------------------------
1978 Argosy 28 foot Motorhome

Wise men talk because they have something to say; fools, because they have to say something. -- Plato


thenewkid64 is offline   Reply With Quote
Old 11-17-2008, 12:05 PM   #19
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,814
Images: 12
I think I am having a little problem making my point here. The fact that you have gas down stream dose not mean the heater will light.

The main gas valve on the heater will only come on after there is PROOF OF PILOT. If there is air in the line the pilot valve is too small to bleed off the air in the time allowed for proof of pilot and the cycle will just time out.
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 11-18-2008, 09:33 AM   #20
WBCCI 8562
 
Jim in Pima's Avatar
 
1975 31' Sovereign
Pelzer , South Carolina
Join Date: Nov 2007
Posts: 225
Images: 5
Couple of comments, sail switch, I have helped several check these out, usually the cause is dirt in the switch, or restricted air flow, either a slow blower, or something blocking the input air (both combustion air or heater air can cause this.) Poor DC connection can do it as well, check these before pulling the furnace
Gas flow, I just went through that, old furnace had not been used in years, I found the line leading to the shutoff valve (under the trailer) was completely blocked, reamed it out with a heavy wire.
No idea what caused it, perhaps moisture at some point.
__________________
Jim in Pima Az, enjoying our 1975 31 ft Airstream Sovereign
Jim in Pima is offline   Reply With Quote
Old 11-19-2008, 08:04 AM   #21
Moderator
 
HiHoAgRV's Avatar

 
1991 34' Excella
1963 26' Overlander
1961 26' Overlander
Central , Mississippi
Join Date: Nov 2006
Posts: 5,329
Images: 29
Blog Entries: 49
Quote:
Originally Posted by HowieE View Post
...The main gas valve on the heater will only come on after there is PROOF OF PILOT. If there is air in the line the pilot valve is too small to bleed off the air in the time allowed for proof of pilot and the cycle will just time out.
Lazy person reply here...
Both my Airstream and SOB suffer form this problem and my method is to get the stove top lit to purge the main gas line. This usually takes a few minutes of holding the firestick ove the burner before she fires up. I can then turn on the heater and if it doesn't fire, I cycle the thermostat to "off", wait 5 seconds the go back to "on". It may take a few tries but she always fires up.
This process can be done with a single had, freeing the other to hold a beverage
__________________
Hi Ho Silver RV! Vernon, Sarah, Mac the Border Collie -
A honkin' long 34' named AlumaTherapy http://www.airforums.com/forums/f205...num-54749.html
and a 26' '63 Overlander, Dolly http://www.airforums.com/forums/f109...ome-71609.html
HiHoAgRV is offline   Reply With Quote
Old 11-19-2008, 09:14 AM   #22
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,814
Images: 12
Quote:
Originally Posted by HiHoAgRV View Post
Lazy person reply here...
Both my Airstream and SOB suffer form this problem and my method is to get the stove top lit to purge the main gas line. This usually takes a few minutes of holding the firestick ove the burner before she fires up. I can then turn on the heater and if it doesn't fire, I cycle the thermostat to "off", wait 5 seconds the go back to "on". It may take a few tries but she always fires up.
This process can be done with a single had, freeing the other to hold a beverage
Yes this will work. But the average individual does not have the patience to go through several cycles and purge the line using the pilot valve and will yield to the service tech who will do just that and charge them for a circuit board.
__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 11-19-2008, 05:59 PM   #23
1 Rivet Member
 
1972 31' Sovereign
Loogootee , Indiana
Join Date: Jul 2008
Posts: 11
Talking

OK, now I am the dummy here. I worked for two hours trying to get the Surburban in the '72 Sovereign to fire up. MAnaged to get gas to the pilot, opened the little bottlecap pilot door and stuc in a match like the manuel said. It didn't say the bottle opening would spew flame like a little rocket. Despite having no hair on that hand now, I'm otherwise unhurt. Now I see a note here about the voltage. I didn't even have the power on, so the durned thing was not going to work no matter what. Oh well at least I have the forum here to fall back on; as long as I don't burn my fingers too much to type.

The things we learn about Airstreams after we buy them would be worth knowing before.
__________________
Maxom is offline   Reply With Quote
Old 11-19-2008, 06:21 PM   #24
Rivet Master
 
1975 29' Ambassador
Reno , Nevada
Join Date: May 2003
Posts: 1,351
Quote:
didn't say the bottle opening would spew flame like a little rocket
This is one reason why the blower is supposed to come on a few seconds before primary ignition. The sail switch is the indicator that the blower is indeed working. A part of the blower runs fresh air through the combustion chamber and it needs to be clear of residual gases before attempting to start up the furnace. On shutdown, the gas valve turns off the main burner and the blower continues for a while to make sure all combustible gases have cleared.

The question is why you got singed. A pilot should not do that even if you held down the thermocouple over ride for quite a while. The gas valve for the primary burner should not open unless the sail switch indicates proper blower operation and a time delay. The thermocouple is the primary safety for gas shutdown if no heat is being produced.

The auto ignition things work a bit differently as they have a sensor to determine if the burner took off and will shut down the gas valve if they don't detect flame after ignition. This is often an ion sensing thing looking for the flame's plasma.

You need to see if you have a leaky gas valve or something. An extra enthusiastic pilot lighting exercise is a warning about a potentially explosive situation.
__________________
bryanl is offline   Reply With Quote
Old 11-19-2008, 10:40 PM   #25
1 Rivet Member
 
1972 31' Sovereign
Loogootee , Indiana
Join Date: Jul 2008
Posts: 11
Thanks Bryan. Actually I have not yet gone back to try anything else, but I think I will try one more time to make sure there is 12VDC going to the thing before I try again. The furnace looks to be in good physical shape, and while I was convinced that the push button spark igniter was not working, I saw that it was after taking cap off and looking into the pilot hole. So it gets spark and it gets gas, sort of. I am still thinking the flash I got was from trying so long to get the pilot to light. And I am hoping that by giving the rest of the system a fighting chance with electricity, it will give me the same result as did the oven and stovetop; both of which work great.

This is a '72 that I bought for $500 on a bet, since it had been sitting on a lot untouched since 1983. The owner of the trailer was not the owner of the lot and there was some bad blood going on there. And the owner lost the key, "a while ago", and had never went back into the camper. I bought it, hauled it home and managed to pick the lock. Inside I found a time capsule from 1983. This was a sort of summer place for the owner's family, and when they left they had every intention of coming back like the next weekend. They left everything. Even the change bowl by the sink, with silver dollars in it. I inherited such odd things as a complete set of the old Spiro-Graph toy, board games, a drawer full of vintage maps, fishing tackle; including some old lures still in the boxes, and all types of kitchen gear, toys, bedding and even clothing. None of that fit. Oh, and of course I will replace the funky green carpeting. Probably use new laminate flooring for that.

When I bought the trailer I intended to gut it and do a remodel. But when I got inside and started cleaning up, I found that the inside was in remarkable shape. About all I now intend to change out is any appliances that don't work and can't be easily fixed, and all the foam cushions in the upholstered areas. Who knew those just turn hard over time and break instead of giving?
__________________
Maxom is offline   Reply With Quote
Old 11-19-2008, 11:48 PM   #26
Rivet Master
 
1975 29' Ambassador
Reno , Nevada
Join Date: May 2003
Posts: 1,351
Quote:
Inside I found a time capsule from 1983

what a story, what a find!

The furnace should be OK. I never found the spark igniter on those to be worth much and found a propane lighter much more convenient. Do check the outside vents for any obstructions. When the blower motor went, I found a auto ignite newer furnace surplus for under $400 and left the pilot lighting behind.

Also, I have heard you need a window on the opposite side of the trailer cracked open to facilitate pilot lighting. Sounds weird but it seems to have made a difference for some.
__________________
bryanl is offline   Reply With Quote
Old 11-20-2008, 05:02 PM   #27
1 Rivet Member
 
1972 31' Sovereign
Loogootee , Indiana
Join Date: Jul 2008
Posts: 11
Brian,
I poked around some more on the furnace. Tried a few more times to do the pilot light, and got it to burn for a few seconds at a time. It looked like a clean pilot flame but it just wouldn't stay lit. Read back through some of the info here and in the manual. Oh yea, forgot to tell you that one of the things I inherited in the trailer was a full shop service manual, along with the owner's manuals for the trailer and all the appliances, etc. The service manual is a wealth of information. It is for the whole line of '73 Airstreams, and mine is a '72. But It can't find any differences between the two.
One of the furnace issues that seemed out of place was the idea that when you turn the thermostat up off the bottom peg, the fan should come on. After making sure I had 12 VAC going to the thing, I tried that and got a click but no fan. I was not yet convinced to try to take the furnace out of its cabinet so decided to look around some more before going that far. The easiest next thing to take off was the outside vent cover. Took that off and found a major problem, and was glad the thing didn't light. The intake side, or the bottom tube, had what looked like a green filter in it. Looking closer I decided it was not a filter but something more like moss. I started poking at that and it came apart to easy to be something that was supposed to be in there. OK, I got a longer probe, which turns out to be a great use for the aluminum rod handle that is for the awning wheels.
Started digging and got out a mass of fiber, moss, insect carcasses, wasp nests and other gunk. The whole wad of stuff was about a coffee mug full. I could then see the fan motor and what I thought was a shaft to the blower, and some more gunk. I decided to see what happened if I turned the thermostat up again. Wow! the fan came on; although it was noisy. I let it run a bit, shut it off and then went back out to examine the fan inside the vent hole. What I could see now looks like the fan itself is totally clogged up with mud dabber nest. That would account for it being out of balance and noisy.
Now I plan to figure out how to get the furnace our of the cabinet. The manual talks about cutting a hole in the shelf to get to a latch that allows you to open the furnace cover. There is already a small hole there that looks like probably someone has been in there before. But I tripped the latch and nothing happened; so far. I'll keep probing gently and get the thing out so I can get it on the work bench. I'm betting a good cleaning and it will all work fine.
__________________
Maxom is offline   Reply With Quote
Old 11-20-2008, 05:44 PM   #28
Rivet Master
 
1975 29' Ambassador
Reno , Nevada
Join Date: May 2003
Posts: 1,351
Quote:
It looked like a clean pilot flame but it just wouldn't stay lit.

on a pilot based device, that is usually a thermocouple problem

Quote:
What I could see now looks like the fan itself is totally clogged up with mud dabber nest.
wasps and spiders seem to like the perfume they put in propane. It is always a good idea to check the furnace and water heater before firing them up each season.

Quote:
Now I plan to figure out how to get the furnace our of the cabinet.
That can be an interesting challenge. It is often a puzzle and there always seems to be some hidden screw or gotcha' to figure out. good luck. You are probably right that it won't take much to get it back into prime working order - once you can get it on the bench!
__________________

__________________
bryanl is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Furnace Won't Fire/ Start jnerges Furnaces, Heaters, Fireplaces & Air Conditioning 47 03-02-2014 06:59 PM
Suburban furnace pjude General Motorhome Topics 4 10-16-2007 09:00 AM
Suburban furnace 34 NT pjude Classic Motorhomes 3 07-29-2007 11:06 AM
Suburban Furnace 68LANDYACHT Furnaces, Heaters, Fireplaces & Air Conditioning 9 02-03-2005 10:20 AM
Suburban Furnace tmeagle1 Furnaces, Heaters, Fireplaces & Air Conditioning 25 02-20-2004 08:18 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:27 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.