Furnace Question

happycamper · 09-10-2018, 02:37 PM

Hello Everyone,

Been a while since I have been active here. I do love this site. I have a 2007 264SR with an Atwood Furnace. The camper is on a seasonal site and for the first time ever I think I may have left the furnace on. My concern is if it should run out of propane will the blower motor keep running? I really do not want to drive all the back 2.5 hours unless I have to.

Thanks
JIm

mainah · 09-10-2018, 03:49 PM

Yes. Can you call the owner of the campground?

krazedave · 09-10-2018, 04:06 PM

I would think that if my 06 264SR's furnace had a fan control board on it that yours has one also. The furnace will quit trying to fire after 3 times and will shut down if no gas is supplied to it.

j52wf · 09-10-2018, 09:43 PM

From an Atwood page:

Depending on the board design, it will try for ignition up to three times. Beyond that point, it goes into lockout mode, will not retry for ignition until reset and the blower will continue to run. Newer circuit board designs will try for ignition three times and then shut everything down to prevent the battery from running down.

Looks like it depends on what circuit board you have. Have a campground person check on your camper from outside and listen for the fan. If not running, you're good. If running, you can drive back.

j52wf · 09-10-2018, 09:56 PM

Another option to driving back, if the fan is running, would be to have the campground unplug the camper and switch the battery cut-off. Only if the fridge is empty though.

mainah · 09-11-2018, 06:10 AM

I am not sure about oem boards older ones did not. Dinosaur replacement boards do shut down on the 3rd try but the oem ones I have replaced do not, did they fix this by 07? I don't know. If it runs out of gas the flame sensor will shut it down but it may attempt to restart and I doubt that it has any logic so it probably would continue to only to fail time out and try again. Having never faced this problem I think I would err on the safe side.

**JohnB** · 09-12-2018, 06:44 PM

H'mm Good question.

I know mine will go into flame lockout if I run out of gas. But the blower... I don't know.

This is fairly easy to test, shut off the LP and let it is run while plugged into shore power and see what happens. I will try and do this test tomorrow to see if on the 2004 models what happens. I'm curious. Never had this issue myself for that long, days worth.

I know if the battery gets drained while boondocking, (in this case a Cpap machine), the sail switch safety will not close due to not enough blower force to close the sail switch. In this case, you get no flame as it will not even try to light so it cannot go into flame lock out. But the blower tries to run and you just get cold air. Now does the blower just keep running until the battery goes dead? Ah don't know. We had this happen to a fellow SOC member on his 2007 T289SR.

I will report back what I find.

Thanks

John

j52wf · 09-12-2018, 07:09 PM

I ran out of propane with my 2475 while on shore power at a campsite. Blower just kept blowing cold air. Couldn't understand why it wasn't getting warm. Lol....now. Had to wait for the office to open. Still wondering how I managed to allow both 30 lb. tanks to go empty.

**JohnB** · 09-12-2018, 09:22 PM

Quote:

Originally Posted by j52wf

I ran out of propane with my 2475 while on shore power at a campsite. Blower just kept blowing cold air. Couldn't understand why it wasn't getting warm. Lol....now. Had to wait for the office to open. Still wondering how I managed to allow both 30 lb. tanks to go empty.

H'mm, Jim you did the test I was about to do on my 2004 T310SR! The 2004 T2475 and the T310SR should have the same vintage control board on the furnace as both were made close to the same manufacturing date.

If bookdocking and having this issue, one needs to wake up if it happened in the middle of the night and shut the furnace off... That fan motor draws a lot of amps. The battery can be drained trying to run overnight.

Thanks for saving me the test...