Atwood furnace - no access door - what to do

Kbarb · 03-04-2019, 11:40 PM

I might have a problem with my Atwood furnace - I might - but I'd prefer to save that for another post when I know more.

I'm pretty good at diagnosing such things, if I can actually get to them.
But my Atwood 8500-IV series furnace on my 2007 31BHDS has no exterior access door, as I've read some models indeed do not.

How do people handle this ? It doesn't seem like it'd be too easy or even possible to get to the control panel or any of the wiring, sensors or relays, as it seems they are on the side facing the outside wall.

I'm thinking of cutting in an exterior access panel, rather than pulling the whole thing out from the inside, if that's what people do.
I see you can buy them online - it can't be that hard with my skill level (if I may say).

Anyone else put an access door in ?

farnik78 · 03-05-2019, 04:12 PM

I don’t think I have ever seen an exterior access door for a furnace. They are usually accessible from the inside only having a vent to the outside.

oldmanAZ · 03-05-2019, 04:22 PM

Quote:

Originally Posted by farnik78

I don’t think I have ever seen an exterior access door for a furnace. They are usually accessible from the inside only having a vent to the outside.

X2

Kbarb · 03-05-2019, 04:30 PM

Interesting.
My brother has the same vintage Fleetwood Terry, and he has an exterior door on his.

Moreover, if you do a search on Google for "atwood furnace repair", then look at the Images page, almost all of them have an exterior access door.
Same with the same search on Youtube.

Am I missing something ?

RichR · 03-05-2019, 04:30 PM

Certain models of furnaces have outside access doors. They can be removed to expose the some of the major parts. Look on Youtube and you see lots of videos related to RV furnace repair showing the outside cover.

Here's an example:

https://www.youtube.com/watch?v=UM2qOfSuCQQ

namusmc65 · 03-05-2019, 06:40 PM

I had the same problem on a Jayco Eagle 5th Wheel and the control board was bad from the factory. Had to unload front basement storage and remove inside wall and then cut a hole through plywood wall to get to furnace to unhook it and remove from unit. Was a 4 hour repair job under warranty for a 10 minute repair if there had been an access door. This is probably my 10th camping rig and first one without an access door to furnace.

Kbarb · 03-07-2019, 10:15 AM

I heard back from Dometic/Atwood :

Quote:

I checked with one of our service technicians and he said that your unit was designed not to have an access door so we do not recommend you cutting anything to place a door in there. I do apologize, I know it is probably not the answer you were expecting.

Great. So they're' worried about liability.
I don't really see how anyone would troubleshoot or use a VOM/multitester to check anything when you can't actually get to anything that needs checking.

I'm thinking just to buy the access door and cut it in.
It's just a hole in a wall, no big deal right ?

skids · 03-07-2019, 11:15 AM

Quote:

Originally Posted by Kbarb

I heard back from Dometic/Atwood :

I'm thinking just to buy the access door and cut it in.
It's just a hole in a wall, no big deal right ?

That is exactly what I would do.

Hog3loves · 03-07-2019, 11:54 AM

Quote:

Originally Posted by Kbarb

I'm thinking just to buy the access door and cut it in.
It's just a hole in a wall, no big deal right ?

Two things I'd be concerned about when cutting a hole in your "box" for an access door: sidewall flex/structural integrity, and water intrusion. Over time both of those might be factors working against your camper's longevity. For the limited number of times you need access (hopefully) over its expected lifespan, is it worth the downside to cutting the hole? That's your tradeoff decision point.

RichR · 03-07-2019, 05:05 PM

Quote:

Originally Posted by Kbarb

I heard back from Dometic/Atwood :

Great. So they're' worried about liability.
I don't really see how anyone would troubleshoot or use a VOM/multitester to check anything when you can't actually get to anything that needs checking.

I'm thinking just to buy the access door and cut it in.
It's just a hole in a wall, no big deal right ?

You may find that your furnace isn't oriented in the same direction as those with an outside access door. I believe the furnaces are all basically the same but how they are mounted may be different. That could present a problem. I would suggest that you track down manuals that cover your model furnace. My Atwood manual has illustrations of the doors and vents, and what model furnace they match to.

Kbarb · 03-08-2019, 10:13 AM

Thanks everyone for your thoughts.

Yes I've thought about the structural integrity and waterproofing issues, but the way I look at is, other penetrations were made to build the trailer, so why couldn't that process be successfully repeated.
If there's really a structural issue there's always aluminum and steel for reinforcement. The opening to be made is only around 7" x 16".
I have plenty of experience remodeling, including skylite installs and roof/leak repairs so this level of modification is pretty elementary.

As for the orientation of the unit, yes I've looked into that as well. I have the manual (which isn't great actually). Plus there are plenty of google images and youtube videos. You just have to do your homework, due diligence, which involves exploratory work to see what lies ahead.

What's surprising is not much turns up when you try to find people that might have posted with similar situations where there's no access door.

Anyway, still pondering it and not picking up the chainsaw right away.

**norty1** · 03-08-2019, 10:30 AM

Most don't have access from the outside for a reason. I know several who have had reason to access theirs to replace the burner in one case and a board in another in 10 years old rigs. It was not a big problem to get to it from inside by removing a drawer and some screws. I have owned 3 5th wheels a MH and a tt and never had occasion to get to it except to blow the burner out with compressed air.

Your choice.

Kbarb · 03-08-2019, 10:38 AM

I've examined and investigated it fairly thoroughly and actually, despite that you can remove the interior grill and clearly see the unit, you can't really service it at all. The essential parts are facing the wrong (inaccessible) direction.
Even removing it if you ever had to would be a major challenge as you can't get to all the installation/mounting screws.

All you can do is perhaps check voltages and so on for the visible wiring.
But that's about it.

It was probably just an economic decision not to leave an access door for customers.

Hog3loves · 03-08-2019, 10:56 AM

Quote:

Originally Posted by Kbarb

You just have to do your homework, due diligence, which involves exploratory work to see what lies ahead.
What's surprising is not much turns up when you try to find people that might have posted with similar situations where there's no access door.
Anyway, still pondering it and not picking up the chainsaw right away.

Sounds like you're more than capable to make this modification. I, personally, would appreciate some before and after pics if you decide to proceed. Thanks.

Kbarb · 03-08-2019, 11:07 AM

Yeh I've thought of making my own silly youtube video, since youtube doesn't really have enough videos already.

CampinFred · 03-08-2019, 11:12 AM

Where does the exhaust from combustion go if there's no panel?

Kbarb · 03-08-2019, 11:43 AM

There is the typical exhaust port that you always see. But that's it. It's not part of an access door, or next to an access door. Just the exhaust port.

MaxDMax · 03-13-2019, 12:42 PM

I just pulled the furnace out of my new Pinnacle 5th wheel because my igniter failed. Mine was accessible behind a basement wall. It took me about 10 minutes to remove it, 15 more minutes to setup a bench test and about another 30 minutes to diagnose and replace the igniter. Took probably 15 minutes to re-install it. Pulling mine out was the only option and by far the easiest way to work on it.

Kbarb · 03-13-2019, 12:48 PM

Hmm, I thought of that and looked, but didn't see anything except the bottom of the floor. I'll have to double check.
Thanks a lot for the comment though.

Sunflake · 03-13-2019, 07:26 PM

Quote:

Originally Posted by farnik78

I don’t think I have ever seen an exterior access door for a furnace. They are usually accessible from the inside only having a vent to the outside.

My neighbors 3 year old trailer has an access door for his furnace on the outside of the trailer. It’s big enough to remove and install the furnace. We opened it and were looking at the control board and there was a sticker to tell you what the flash codes meant. I haven’t tried this myself but have you ever used an inspection mirror to look at the board from the inside?

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