Suburban Furnace Help

[kwood]

Hello all!

I plumbed my bus with 1/2" black gas pipe and picked up an older suburban furnace.  I wired it with a 2-wire basic thermostat.  When I turn the thermostat up the fan for the furnace kicks on, but we are having trouble getting the pilot light to ingnite (actually we don't smell any propane either.  I have a shutoff before the short line to the furnace.   I unhooked that last night and cracked the valve to see if gas is getting that far and when I crack the shutoff there is a faint hissing noise and I can smell propane, so I know I am getting gas that far. 

There are four wires coming out of the furnace.  What I am wondering is if I have those wires hooked up correctly.  I am thinking that maybe there is a switch in the furnace that does not let propane flow internally if there is incorrect wiring.  The thing that puzzles me, though, is that we press the reset and tried to ignite the pilot light with a long lighter and it still does not work.  I thought that if you pressed and held the reset it would allow gas to the pilot and bypass the furnace.  Maybe I am wrong.

Any advice would be appreciated.

Thanks,

Kevin

[Len Silva]

Depending on the age of the furnace and whether or not you have manual ignition or electronic.  The manual type would be quite old.
Without specifics, you most likely need 12 volts to the furnace (that would be two wires, probably the larger if there are two different sizes), and two more, perhaps smaller, to the thermostat.  Polarity would matter on the supply leads but not on the thermostat leads (they are just a switch).

Pressing and holding the reset may take a long time (seems like hours when you are holding it down) to let enough air through the very tiny pilot orifice before you actually get gas there.

If you post the model number of the furnace, we may be able to help more.

[RTS/Daytona]

There is an all important "sail switch" on most heaters that prevents the gas soleniod from opening  if a "breeze" from the fan does not close the "SAIL SWITCH"

here's some SUBURAN furnace manuals - from the very helpful "Classic GMC motorhome" folks - of which I am still an active member

http://www.bdub.net/manuals/solaire.pdf

http://www.bdub.net/manuals/SuburbanDynaTrail.pdf

http://www.bdub.net/manuals/Suburban%20NT%2022A%2022C%2022CD%2032A%2032C%2032CD%20DTM%204-76.pdf

P.S. If you have a control module - most RV places have a Furnace module TESTER

[kwood]

Thanks, guys!  We got it lit!!  We now have lights, electricity (12v and 110), and heat.  Running water will be a spring project.  That and doing trimwork and we are good to go.

Kevin

[fe2_o3]

What did you find on the furnace problem. One of mine is acting up now....Cable

[kwood]

We just were not waiting long enough for the propane to move to the unit and then not holding down the reset long enough for the air to purge and propane to reach the pilot.  After holding the button quite awhile we finally smelled a bit of gas.  We then waited a bit for the smell to disipate and then tried again.  It lit.