Atwood Furnace Issue...

[ATCguy]

Ok guys, help me out here...

Am back in NC, living in my rig while continuing to recover from my spinal surgery. With this latest cold front, temps are now routinely falling below freezing at night.

The issue is the furnace is not coming on when the inside temp dips below the thermostat setting. The 20amp fuse is good. I can go outside, remove the cover, and I see the fault code light blinking once every 3 seconds. No apparent mechanical issues. I can manipulate the blower fan fins with my fingers... bang the side of the blower motor with my hand, cylcle the "reset button" off-on... and the blower motor starts up, the igniter lights, and it runs normally. The temps rise inside the rig, and all is ok... until the temp falls below the thermostat setting again, and the furnace fails to operate again until I go back outside again and go thru the same thing.

This has happened 2 nights in a row... and I'd like for it to not be 3 or 4. Any suggestions?

I know I've seen something similar to this discussed before... but after searching 6 pages thru this forum, can't find it.

I'd like to try rectifying this myself, but I'm limited by what I can do. I still don't have a working use of my right arm, so I'm not sure tearing the unit apart is an option. That said, I can get some help, if needed.

[snakebitten]

Tom,

Sure hope you find an easy solution. (I am of no help there though)

But for these cold nights, until you DO find the fix, why don't ya grab one of those cheap infrared heaters just so you don't have to brave the cold outside in the middle of the night? That's gotta be a frustrating experience when you are warm and cozy in your jammies.

[TomW]

In the meantime get a couple of small 750 - 1500 w cube heaters. They work wonders, have thermostats, and save your propane

[ATCguy]

Yeah, way ahead of you there...



I've been using the 2 electric ceramic heaters that I've used for a couple of years now. One in the rig for me, and one in my basement to keep the water pipes from freezing. Since my electric is included with my campground fee, I figure why not use them instead of paying for propane to run the furnace. But the last couple of nights, it's needed a little help from the furnace occasionally to keep me comfortable. Of course, that's when I found out that the furnace wasn't working as advertised w/o me gong out to remove the cover, etc...

[snakebitten]

Ok. Good news.

Just didn't want ya to freeeeeeeeze.

I've been full-timing for 8 months or so and haven't even opened the valves on the propane tanks. I keep saying I'm going to just to put everything through the propane process. But the water heater works so well on electric, and both fridges, as well.

Since it only gets onto the 40's around here, for the most part, the "cube heater" conquers the cold just fine in 160square feet.

[drogers]

Sorry to hear about your problems. out of curiosity just how cold is it getting at night and what are the day time highs? Wondering because I'm about to spend ten days in mine. day time highs here today is -15'F night time lows are around -22'F. electricity is available so I will have electric ceramic heaters as well, but I'm worried about drawing to much current running two 1500W heaters as well as the furnace, lights and de-humidifier. No water needed, so I will leave the unit winterized. Thought about running a separate extension cord for one ceramic heater but can't figure out how to get it into the RV without opening a door or window. Any thoughts.

[ATCguy]

Having spent my last 3 winters in either FL or AZ, I've only had a few cool nights since I've been full timing... which is why I guess the furnace hasn't been an issue. Although, as I think about it, I have fired it up occcasionally, and it's always come right on. Figures it'd only start acting up when I really need it.

Derek...
Wow. No, I'm not anywhere near hose kind of temps. Low last night was 23... it's up to 40 this afternoon. Wx forecasts says I can expect similar temps all weekend.

[sundancer 87]

Originally Posted by ATCguy

Ok guys, help me out here...

Am back in NC, living in my rig while continuing to recover from my spinal surgery. With this latest cold front, temps are now routinely falling below freezing at night.

The issue is the furnace is not coming on when the inside temp dips below the thermostat setting. The 20amp fuse is good. I can go outside, remove the cover, and I see the fault code light blinking once every 3 seconds. No apparent mechanical issues. I can manipulate the blower fan fins with my fingers... bang the side of the blower motor with my hand, cylcle the "reset button" off-on... and the blower motor starts up, the igniter lights, and it runs normally. The temps rise inside the rig, and all is ok... until the temp falls below the thermostat setting again, and the furnace fails to operate again until I go back outside again and go thru the same thing.

This has happened 2 nights in a row... and I'd like for it to not be 3 or 4. Any suggestions?

I know I've seen something similar to this discussed before... but after searching 6 pages thru this forum, can't find it.

I'd like to try rectifying this myself, but I'm limited by what I can do. I still don't have a working use of my right arm, so I'm not sure tearing the unit apart is an option. That said, I can get some help, if needed.

FURNACE OPERATION OVERVIEW
This is generic description of RV furnace operation and applies to most DSI type furnaces.
1. The Thermostat calls for heat, sending DC current to the furnace.
2. A Time Delay Relay is energized and passes battery DC power to the blower motor.
3. The blower motor and fans spin, pulling air from the Air Return and generating a stream
of air through the Heat Exchanger and out the Ducts. At the same time another fan pulls
air from the Combustion Air Intake into the Combustion Chamber and out the Exhaust.
4. The fan air stream causes the Sail switch to close as the blower gets near full speed.
5. Power flows to the High Limit Switch and onward to the Control Circuit Board.
6. The Control Circuit Board opens the gas valve and generates a spark at the DSI Igniter.
7. The Burner ignites, building heat in the Combustion Chamber.
8. Heat passes through the Heat Exchanger, warming the air circulating through the Ducts.
9. The Thermostat reaches the Set Temperature and opens.
10. Power is removed from the Control Board and the Burner shuts down.
11. The fan continues to run to cool the furnace, until the Time Delay Relay opens again.

Pay particular attention to item #2. Your furnace operates as it should AFTER the the blower motor starts, in your case the second method of operation isn't happening, therefore rendering the thing inoperable.
Perhaps with the banging on the furnace the relay makes contact and the operation continues. I'd start with the relay.

[nonsense]

ATC,

I had a very similar situation this fall during our trip to Colorado. Mine was super touchy, sometimes it would work and sometimes it wouldn't. I alike you had not used mine much but had never experienced any issues when I did need it. I also had 1 flashing light on my board like you. The crazy thing mine did though was; run all day without any issues and then at night it would just quit, wouldn't work at all, then about 7 a.m. it would come on and start working. Occasionally it would randomly kick on one time in the middle of the night. We were experiencing similar temperatures lows in the mid to low 20's at night and highs about 45 during the day.

Solution was one of two things. I reset the thermostat, apparently there were some programs set in it that I couldn't get cleared. I also took a look at my LP line and sure enough it was kinked really bad, I'm assuming the furnace wouldn't recognize enough L.P. pressure? The kink was right below the tank selector switch where the loop in the line is. It was folded almost in half, on the same trip i had one time where my fridge blew out. I chalked it up to a very windy travel day, but looking back may have been low L.P. flow. Since I addressed both of those issues I have not had any issues, and have camped in the cold several times.

Good Luck