Old Atwood heater

[Vonvergmann]

Hi everyone. Thanks for the great help with my Riggy question the other day. Now all of a sudden I’m having a problem with my old Atwood heater on my 2002 hawk. I’ve read every possible thread watched a bunch of videos, even called Zac at four wheel camper to no avail. The heater turns on sounds like it wants to ignite but won’t stay lit. I pulled the back off there’s no sales switch and I was told there’s no sales switch on this model. Of course I have a big trip coming up on Monday and I’m really sorry for not being able to suss this out through the forum posts of the past. Can anyone point me in the right direction? Thanks in advance for all the help. This form has been so helpful to me. Mel

 

[Vonvergmann]

Well, never mind. Took it for a drive and it works again. Will check for loose connections. Thanks!

 

[veryactivelife]

Could have been low battery voltage and the drive gave enough of a charge to start the furnace.

 

[Jack]

If your Atwood is similar to the one I had on my 2005 Eagle, there is a trouble LED on the circuit board (take the outside cover off to see it). I had similar intermittent problems, and found that a Y crimp was loose. Check all of the crimps on all of the Atwood wires.

 

[Vonvergmann]

Thanks for the crimping tip. It doesn’t wanna start after it sits for a couple days but as soon as I drive it around it’s fine I’ve got it plugged into shore power and I have a brand new battery, so I’m puzzle but I’ll look at that. I pulled the cover off and it looks like that whole thing has been through a war. I take this thing out to some very dusty locations.

 

[Taku]

a good gentle cleaning. had a stereo that was years old. was crackling and bad sounds. took the cover and years of cat and dog fur and hair and dust. did a thorough gentle cleaning and it sounded great. Maybe that and loose wires will fix it/

 

[Wildcat]

I had the exact same issue on my atwood (domestic) furnace, 2001 eagle. I think FWC used the same furnace on all models of that era. It was the gas valve and haven't had any problem with the furnace since replacing it 6 years ago. DOMETIC 31150 Kit, Gas Valve Side Out, 12Vd https://a.co/d/5tGc2Nk. This is a common problem as these furnaces age. I'm very surprised that Zack did not suggest it. When I bought the gas valve it was called an Atwood part. Now listed as DOMETIC. There are different configurations of the valve based on the particular furnace size and orientation. If you want to confirm the part number you need to view the label on the side of the valve which is hard to do unless you remove it, and it's probably covered with dust ( mine was). I think I found a video on YouTube for replacing it. Just Google for the Atwood gas valve. It was used on many RVs and not just FWCs.

In 2018 when I was having the problem with the furnace I attended a FWC rally where the factory sent a tech person to go around and review and possibly fix people's issues at the rally. I had the tech look at my furnace and he also couldn't come up with a solution. Ultimately it was a friend with a 2004 Hawk who knew what to do as he recently replaced his gas valve. Unless a tech person has gray hair, he probably doesn't really know the old units, but I'll bet that the guys at All Terrain Campers can point you in the right direction and would probably suggest the gas valve as their first guess if the battery is good. After that, the circuit board or electrical connections but the gas valve is the cheapest first step as opposed to replacing the circuit board.

 

[Vonvergmann]

Thanks Wildcat for the 411. I will look into this. Calling All Terrain is also on my todo list. Really appreciate taking the time.

 

[Wandering Sagebrush]

Thanks for the crimping tip. It doesn’t wanna start after it sits for a couple days but as soon as I drive it around it’s fine I’ve got it plugged into shore power and I have a brand new battery, so I’m puzzle but I’ll look at that. I pulled the cover off and it looks like that whole thing has been through a war. I take this thing out to some very dusty locations.

Because it reoccurs after a few days of no use, I think you have a power issue. I’d check your battery voltage after the camper has set for a few days, and then again after driving. My guess is the battery is nearing end of life, or possibly a small voltage draw from another circuit.

 

[Old Crow]

Mel-

I had a similar problem with the Atwood in my 2001 Hawk. I found the center wire of the electrode was broken loose in the ceramic insulator, allowing it to turn when it's supposed to be fixed.

My furnace's unreliable-start problem turned out to be the electrode

Also- You mention your furnace doesn't have a sail switch. I don't think I've ever seen an Atwood furnace that doesn't have one. There's typically a model-number sticker readily visible when you take off the outside cover. You might try doing a Google search for that model number and the word "sail" to see what turns up.

Also- You might try having someone turn up the thermostat to start your furnace while you're outside at the furnace. Listen as the furnace goes through its Sequence of Operation. (For my 8516-IV it's page 17 of this manual). You should be able to hear the gas valve click and also smell a whiff of propane just before the ignition attempts are made.

There should also be a sticker there to help you understand the flash codes for the LED on your control board.

Also- here's another unreliable-start thread on the 8516-IV. Good photos there.

Atwood Hydro-Flame 8516-IV Furnace Repair

 

[Wildcat]

Just to summarize the responses for future people searching this topic, all the above recommendations are valid and fixing a non-working or non-igniting furnace requires some patience and troubleshooting. Some of the symptoms might be similar to other people but the cause of the problem and subsequent fix can be different.

In my case with the bad gas valve, they get sticky with old age. It's basically an electro-mechanical piece composed of a electrical solenoid that moves a shaft to open/close a gas valve. Mine would not work when cold and then would sometimes work and sometimes not. I could hear the furnace sparking and trying to ignite the gas and but my initial diagnosis was that the house battery was weak in cold weather. However my testing of the battery did not confirm that condition. The electrical connections seemed to be good. Finally my friend suggested replacing the gas valve. For the cost of doing so it was worth my time versus having a shop check it out although replacing the valve was a pain because of the tight clearances to get to loosen the connecting pipes.

 

[Vonvergmann]

So before I started to tear apart the furnace, I rang All Terrain Campers. I honestly don’t know who I spoke with, but he was very familiar with this heater. Here are a few things I learned from that call I thought I might share.

First off, this unit is no longer in production, and current similar models don’t fit in the existing cavity. So repairing this unit is the only option available.

Second, and most importantly, it was suggested I take a small stick and poke around behind the squirrel cage. The point of this, I believe, is to knock some sense into the sail switch. It sounded like hocus pocus, but I had nothing to lose. I ran a dowel into the unit as described, poked it around a few times, and went in to turn on the thermostat. It worked! I let it run for awhile, and tried again later. Again it turned on and cranked out heat. I’ll order a repair kit to have on hand, but for now I’m leaving it alone. I know this is a FWC forum, but ATC, along with this forum, has been nothing but generous with their time and knowledge. I’m very grateful. Huzzah!

 

[Wandering Sagebrush]

So before I started to tear apart the furnace, I rang All Terrain Campers. I honestly don’t know who I spoke with, but he was very familiar with this heater. Here are a few things I learned from that call I thought I might share.

First off, this unit is no longer in production, and current similar models don’t fit in the existing cavity. So repairing this unit is the only option available.

Second, and most importantly, it was suggested I take a small stick and poke around behind the squirrel cage. The point of this, I believe, is to knock some sense into the sail switch. It sounded like hocus pocus, but I had nothing to lose. I ran a dowel into the unit as described, poked it around a few times, and went in to turn on the thermostat. It worked! I let it run for awhile, and tried again later. Again it turned on and cranked out heat. I’ll order a repair kit to have on hand, but for now I’m leaving it alone. I know this is a FWC forum, but ATC, along with this forum, has been nothing but generous with their time and knowledge. I’m very grateful. Huzzah!

You probably spoke to Marty Austin, the owner of ATC, and if you have an older Four Wheel Camper, there’s a good chance that Marty was one of the folks who built it.

ATC does repair work on older FWC campers, but I’m not sure what the upper limit cutoff age is. If you have work that you can’t perform yourself, I highly recommend giving Marty a call. The ATC team is customer focused, and they do great work at reasonable prices.