Scamp Suburban furnace servicing

[Ramsey]

Scamp Suburban furnace servicing
With fall approaching I decided to try my furnace. As expected, upon turning the thermostat on and turning up the thermostat up the fan kicked in, however, the heat never kicked in. I tried cleanilng the gas lines procedure as noted in the Surburban manual. Still no heat. I replaced the regulator since this is an older scamp (’93) and that can be a problem. Still no go. It’s looking like it may need servicing. The question becomes whether to remove the furnace for servicing or take the trailer to a rv repair shop. Anyone have a similar experience? It looks like a few rivets are attached on the front flange with not much else securing it???? Anyone have any experience with older Scamp furnaces
Thanks for any feedback….Ramsey

[Carl Pa]

Did you set the thermostat past the temperature in the camper. Carl

[Wayne Collins]

Did you open the valves on the LP tank(s)?

It takes a while for the furnace to light.
First, it has to purge (blow out) any old gasses, then ignite the LP.
If no LP is present at the gas burner, it shuts down.

[kootenaigirl]

When ours was doing that our thermostat on the wall was broken, that may not be your issue though but it is an easy fix if it is with a new one.

[Ramsey]

yes the gas was turned on....lit the cooktop burners as well.

[Mike Magee]

Have you checked the battery voltage? If insufficient, the sail switch won't open to allow gas to enter the furnace and burn, and all you'll get is fan. A battery in decent shape and with sufficient charge should read something like 12.5V-12.9V.

If that checks out, and you have made sure there are no spider webs or such in the orifice, I don't know what else to try. Most folks take the whole trailer in for service, not just the furnace.

[Ramsey]

Voltage checked out at 12.7. Whats the best way to access the orifice for cleaning?

[Ttocs M]

I had similar furnace problems with my 2005 Scamp surburban; replaced thermostat, and took Scamp to RV repair....3 times! Post repairs, make sure the RV repair guy turns furnace on while you are watching to make sure repairs were actually done correctly. I also bought a ceramic portable electric heater for times camping w. power. Actually, I like the heater better - more quiet.

[Dudley]

1 Light you stove first to make sure that the lines have gas not air.
2 try firing up the furnace, if it doesn't light after a few tries, then I would pull the unit and check the sail switch as the gas will not turn on if the sail switch for the fan does not activate properly.
3 If that doesn't work you may have a plugged jet.
4 pull the unit and check for dirt and bugs

They are a pretty easy unit to take apart but if you are concerned about servicing it then yes have a tech check it out.

I did make up a doc showing how to change out to newer style fans on the Casita forum and have included it. It shows what screws you take out to remove the unit. BTW the newer fans are much quieter that the metal ones.

Sorry the pdf is too big to post, PM me if you want a copy

[Joe Romas]

Our Casita has a Suburban furnace.

Sounds to me like the "sail switch" is not being operated when the fan is running. If the sail switch is not operated the gas will never come on.

Normally when the switch is operated the control board will turn on the gas and you'll hear a click of the gas solenoid.

Several things can cause this.

If on battery power the voltage could be low.
Blower motor might need lubricated.
Blower motor bad
Switch is hung up on something
Switch is bad

As I remember you can see the "sail" operate with the front cover off.

Joe

[BillF]

Had the same problem. Found that the 'sail' switch was rubbing on the cabinet and not allowing the gas to turn on. The sail micro switch sits in the fan air flow, has a big tab on it that catches the air and has to close before the gas can turn on. If you take the front off, the 'sail' switch is located near the back lower left corner and can be seen with a flashlight looking between the inner housing and the outer housing (hopefully I remember its location correctly, its been years since). Check if it is free to move without restriction with a long piece of something. If you can't reach it, you will have to remove the heater (not a bad job - just the gas fitting, a few wires and a few screws) and check it. I took mine out and disassembled half the heater before I knew it existed and found the rub.

Good luck. Hope it is that simple

[Ramsey]

As mentioned in a previous post ...In order to start my furnace, i turned on the gas on the propane tank. I then lit the individual stove top burners to make sure propane was flowing. I then turned the thermostat on and adjusted the temperature until the blower kicked in. Heat was never generated while the blower was running for a considerable amount of time. I'm guessing it's a switch issue. Also, i did install a new Camco 2 stage regulator. This had been mentioned in serveral YouTube videos as a potential problem with the firing up of RV furnaces. Regulators have a tendency to begin to fail after 10-12 years. Still no heat.

Thanks for all the suggestions offered. Not sure I’ll tackle just yet. I did find a Servicing manual (pdf link below) It provides some useful info regarding many Surban furnace models. Included are the steps for removing furnace for various models
http://www.bdub.net/manuals/Suburban_Service_Manual.pdf

thanks, Ramsey

[Ramsey]

Originally Posted by BillF

Had the same problem. Found that the 'sail' switch was rubbing on the cabinet and not allowing the gas to turn on. The sail micro switch sits in the fan air flow, has a big tab on it that catches the air and has to close before the gas can turn on. If you take the front off, the 'sail' switch is located near the back lower left corner and can be seen with a flashlight looking between the inner housing and the outer housing (hopefully I remember its location correctly, its been years since). Check if it is free to move without restriction with a long piece of something. If you can't reach it, you will have to remove the heater (not a bad job - just the gas fitting, a few wires and a few screws) and check it. I took mine out and disassembled half the heater before I knew it existed and found the rub.

Good luck. Hope it is that simple

Bill,
thanks for your response. I located the sail switch it just as you described. The sail switch moved freely. It activated when the fan came on....just no heat. May have to pull the unit and have it serviced. thanks again for your thoughts.
Ramsey

[Joe Romas]

Have you checked the sail switch yet?

No sail switch operation = no gas valve operation

Joe

[Mary F]

Moderator's Note: This thread is a merger of duplicate threads. As some suggestions were made (by different people) on each of the original threads, this new version of the thread has some redundancy. C'est la vie.

[Ramsey]

Originally Posted by Joe Romas

Have you checked the sail switch yet?

No sail switch operation = no gas valve operation

Joe

Joe,
yes, the sail switch moved freely when i manually moved it. When i activated the blower the switch activated as well......Ramsey

[Ramsey]

Originally Posted by Mary F

Moderator's Note: This thread is a merger of duplicate threads. As some suggestions were made (by different people) on each of the original threads, this new version of the thread has some redundancy. C'est la vie.

wasn't sure how to remove the duplicate post. Could you tell me the procedure?
thanks for linking together.....Ramsey

[Mary F]

Hi, Ramsey. You can edit or delete a post for a few hours after it's first posted, but if it's the first one in a thread, I don't think it works the same way. In other words, I don't think a Member can delete a thread, even if they are the Original Poster (OP). Merging duplicates requires (required) moderator intervention. About the only thing you could have done differently would have been to notify one of the site team that our help was needed. It's all taken care of for now, though. Back to some good discussion on the furnace servicing.

[Joe Romas]

Ramsey.

Since you've verified the sail is not hanging up maybe you can turn the furnace off and reach in with a long bent wire of something and operate the sail by hand and listen for the switch to "click"

I don't know if that is possible or not, just a suggestion and would depend on ambient noise and your hearing

Joe

[Byron Kinnaman]

Sometimes if there's air in the propane line it takes a few minutes for the furnace to kick on. Listen for ignighter, it'll buzz a bit when trying to light furnace. Let it go for a few tries before giving up. If you don't hear the buzz there's stuff to look at like sail switch, the actual ignighter.
Good luck