Furnace not working...

[CO Dude]

Hey everyone.

The furnace in my Scamp is not working properly. Here's what I know:

The stove is getting gas.
I can hear the fan kick on and can feel it, but it never does anything after that. I know it can take a few minutes for the heat to kick on, and in the past it would eventually start up. Having had this trailer only a year now, I just don't know it's kinks and hiccups that well. I just know it's never turning to heat.


If someone could steer me in the right direction on what to look for I'd appreciate it.

[stevebaz]

Measure your voltage at the fan. If the fan doesn't spin fast enough it wont trigger the switch to light the burner. Do you hear the ignitor trying to light?

[kb1flr]

I agree with Steve on listening for the ignition switch. Also, I sometimes need to light the stove burners and let them run for a minute. This seems to prime the gas lines.

Rick

[Bob Miller]

The furnace needs to see the sail switch activated by airflow before the gas valve will open.. If it doesn't activate, it will never start. If you Google your make and model number + service manual, you will get an exploded parts view and can identify the location of the sail switch. Here's some tips:

1. If you are only on battery, try hooking up the ac shore power or connecting the lead from your TV to kick up the battery voltage.

2. Look inside the furnace from the grill side. If you can see the sail switch lever, try pulling it forward with a piece of wire bent into a hook at the end.

3. In any case, try cycling the furnace at least 5 times before giving up. That means to turn it on, let it run for a few minutes, and turn it off at the thermostat. When it shuts itself off, then cycle it again.

BTW: Did you verify that there wasn't a small LP ON/OFF valve in the line near the furnace's gas input fitting?

Let us know what happens.

[AKscamper]

I had the exact same problem on my 13" Scamp. It worked once I purged the gas lines by turning off the propane tank, turning on the stove burners and attempting to light them (they didn't light). Then turning burners off, propane back on and trying the furnace again. Do you hear it try to ignite? A slight clicking sound? You should be able to look in the burner window and see a little flame if the igniters fire off.

[CO Dude]

I don't think I hear it trying to light. My battery has nearly 11v charge, which is good since I haven't touched it in two months. I'm not exactly sure how to check the voltage on the furnace itself. I tried getting it off a red wire but got nothing.

On our last outting it worked the first night but not the second.

I've bled the lines a few times. On the first night it had the problem as well as today when fiddling with it. So it's getting gas to the area.

Thanks for the help.

[Derek Johnson]

Your battery should read 12.75 volts when fully charged and about 12.25 volts when it is 50% charged. If you only discharge it to 50%, it will last for many more charge cycles. Also, the longer you leave it discharged, the worse it is for the battery--get a charger on that thing...

As to the furnace, there is a specific sequence of events that have to take place for it to ignite. See if you can find a maintenance guide for your model furnace. On mine, the next step would be for the air from the fan to push against the "sail switch" (literally a small piece of sheet metal that is attached to a switch). This tells the furnace that the fan really is spinning, so that it is safe for it to proceed to the next step, which I think is opening the valve for the gas to flow and then triggering the ignitor. A stuck sail switch seems to be mentioned frequently. Or, perhaps the very low voltage from the battery is causing the fan to spin too slowly to move the switch.

Derek

[mszabo]

11volts isn't enough to run it.
Charge your battery.

[Bob Miller]

Originally Posted by CO Dude

I don't think I hear it trying to light. My battery has nearly 11v charge, which is good since I haven't touched it in two months. I'm not exactly sure how to check the voltage on the furnace itself. I tried getting it off a red wire but got nothing.

On our last outting it worked the first night but not the second.

I've bled the lines a few times. On the first night it had the problem as well as today when fiddling with it. So it's getting gas to the area.

Thanks for the help.

11 Volts is, by definition, a dead battery. Try again when you have a minimum of 12.5 volts available, either from the battery or from the converter.
BTW: Running your battery down that far will shorten it's life as well as start a reduction in available amp/hour storage. In short, your battery won't last as long.

[CO Dude]

Huh, didn't realize the voltage reading didn't change much when at half capacity.

I think I'm realizing the battery is bad. As I mentioned, haven't had the trailer long and am still learning. I'm going to charge it in the a.m. and I bet the furnace fires up.

[Donna D.]

Originally Posted by CO Dude

Hey everyone.

The furnace in my Scamp is not working properly. Here's what I know:

The stove is getting gas.
I can hear the fan kick on and can feel it, but it never does anything after that. I know it can take a few minutes for the heat to kick on, and in the past it would eventually start up. Having had this trailer only a year now, I just don't know it's kinks and hiccups that well. I just know it's never turning to heat.


If someone could steer me in the right direction on what to look for I'd appreciate it.

Help us, help you! Put the year of your trailer in your profile. Really, some solutions may be different based on the vintage of your trailer... honest!

[CO Dude]

Just now got around to checking my situation further. Been a crazy week!

When I hook up to power, my heater works just fine. It's obviously the battery, which I'm sure has been sitting around for several years with not much use. After doing some research, I think I'm going to replace it with two 6v's. And hopefully soon some solar as well to keep it charged. We do plan on doing a fair amount of boondocking and I'm realizing this is a must.

On a side note, because I'm so excited, Our Element broke down on us one last time this week and the next thing I know we're at carmax selling it and having them ship a 2005 4runner v8 here!!

And since we just made a major purchase and we're trying to save money, am I ok putting off my batter issue and just do hook ups and our coming trip? Will it be an issue for any reason? I couldn't think of why, but I'm obviously not as educated about batteries as I thought I was.