Scamp furnace issues -

[John Carter]

Need help troubleshooting Scamp furnace -

Would like to know if fan will turn on without propane hooked up or does it need a certain pressure of propane to operate? Does the furnace lockout with out propane pressure?

I have verified that I have 12v at the thermostat and 12v going to the furnace - looking for an easy solution before pulling it out.

Thanks,

John

[melissab]

My Scamp furnace fan operates on all 3 modes. Others will be able to jump in an help you with trouble shooting.

Melissa

Originally Posted by John Carter

Need help troubleshooting Scamp furnace -

Would like to know if fan will turn on without propane hooked up or does it need a certain pressure of propane to operate? Does the furnace lockout with out propane pressure?

I have verified that I have 12v at the thermostat and 12v going to the furnace - looking for an easy solution before pulling it out.

Thanks,

John

[Byron Kinnaman]

If you look for the model number you can get the manual from the manufacturer or the document center here.

Now to answer some of your questions.

The runs on 12 Volt DC from the battery or the converter. It will come on when the thermostat is adjusted to a point where heat is called for. When heat is called for you should not be able to read any voltage across the two leads coming to the thermostat. The thermostat is simply a switch, you can take a jumper and connect the two leads together and the fan should come on.
The fan has to be running and move enough air to move the sail enough to allow gas to flow to burner. Without enough air no gas no flame.
Once gas is going to the burner the igniter sparks and you get flames. When the temperature at the thermostat reaches the temperature the thermostat is set for the switch opens and gas stops flowing. The fan continues to run for 2 or 3 minutes then shuts off.

I have has the one small wire inside the thermostat brake in such a manner you couldn't see that it was broken. A new thermostat was less than $5.00.

[mszabo]

John, my thermostat has a small switch on it. Don't ask me how I know.
Make sure your battery is charged and or you are using shore power through the convertor.

[beardrum]

If I raise the T-stat enough so that it calls for heat, the fan will run for a couple minutes even if the propane is off.

[Byron Kinnaman]

Originally Posted by beardrum

If I raise the T-stat enough so that it calls for heat, the fan will run for a couple minutes even if the propane is off.

That's the way mine works.

There are some thermostats that have an additional switch on them. Mine doesn't when I turn it all the down there's some resistance, when I move it a bit more it opens an internal switch.

[John Carter]

I'm really getting frustrated now....As far as I can tell Scamp begins with a furnace and the wires then builds a camper around it - man is that a tight fit. So I'm still in no furnace fan clicking on mode. I have jumped the thermostat with no luck, I know that I have 13.5 volts going to it... Which might possibly be an issue. On top of the furnace states a max of 13 volts. Is it possible that the 13.5 volts fried something? I tried running straight off 12 volt battery but still nothing. I still think there is some lockout that is stuck.

Any new ideas??

Thanks John

[Carol H]

Well if you have put the switch to on on the thermostat and cranked it up - you should hear it clicking to start up (or on mine it does) Perhaps your thermostat is toast.....

[Bob Miller]

A sticky or defective "Sail Switch" is one of the most common problems with RV furnaces. If the sail switch isn't tripped the circuit to the gas valve will remain open. Some times you can push on the sail with a long wire to see if it is sticking. As mentioned earlier, get the factory docs on-line and check out the sail operation and the switch itself, it's just a small microswitch.

[beardrum]

My furnace is a Suburban NT-12SE. As I recall, there is an on/off rocker switch on the right side of the furnace, very near the gas connection. In my 13', I have to get to it from under the sink. It's almost impossible to see, but I can feel it. I found it by looking at the manual, which is good for the NT-16SE and NT-20SE furnaces as well. It says neither power or gas will flow to the furnace unless it's on. Is there any chance that got turned to off?

Just a thought,

cg

[John Carter]

Got it going thanks for all the suggestions, turned out to be switched polarity from the new style converter that I installed two years ago - oops.

John

[mszabo]

John, thanks for getting back and letting us know what you found wrong.
The problem was one of those you have to be there to trouble shoot.
Looks like you did your due do diligence and traced it down.
Good job!

[jhock]

We noticed the other night for the first time the fan was running and the thermostat turned to off. We unplugged outside power and after awhile it stopped. Why would it start running when the thermostat is on off?

[glennco]

The suburban thermostats have a detent you can feel even after it is turned down all the way as others have said, the switch feels like it stops, then it will click as it shuts off

[steve dunham]

Some tstats have 40 deg low setting / detent / off to provide freeze up protection