Community Forums

RedGuy · 09-01-2008, 11:16 AM

I posted abit of this in a previous thread. But today I took my furnace out since I haven't been able to get it to light since this spring. The fan runs, I can smell gas at the proper time, and hear the ignitior going, but get no ignition and it shuts the ignition sequence down.

So I was trying to take this thing apart so I could give it a thourough cleaning, BUT I can't figure out how to take it apart! I though there'd be some access panels screwed on or something, but it appears as though the whole housing is riveted together. I can't even get the ignitor out! Looked like there was only 3 screwes holding the assembly in, but it still won't come out so there must be more.

The furnace is an Atwood Hydroflame 8520. Any help would be greatly apriciated. Essecially something like a manual on how to dissassemble the thing!

RedGuy · 09-01-2008, 11:16 AM

I posted abit of this in a previous thread. But today I took my furnace out since I haven't been able to get it to light since this spring. The fan runs, I can smell gas at the proper time, and hear the ignitior going, but get no ignition and it shuts the ignition sequence down.

So I was trying to take this thing apart so I could give it a thourough cleaning, BUT I can't figure out how to take it apart! I though there'd be some access panels screwed on or something, but it appears as though the whole housing is riveted together. I can't even get the ignitor out! Looked like there was only 3 screwes holding the assembly in, but it still won't come out so there must be more.

The furnace is an Atwood Hydroflame 8520. Any help would be greatly apriciated. Essecially something like a manual on how to dissassemble the thing!

RV Wizard · 09-02-2008, 12:39 AM

I don't know that I have seen a manual on how to assemble and dimantle a unit but here is a link that might help you. You may have to drill out the rivits and replace when you put it back together. Good luck and keeep us posted.

RedGuy · 09-02-2008, 07:30 AM

Thanks that's actually what I was thinking too. I've been calling a couple RV dealers to see what it would cost to have them fix it, but it's pretty much $100 just to look at it. Considering I can buy this same unit from JCwhittney for %480 I don't want to get into a spot where I have almost as much into a 20 year old funace as I would if I bought a new one. I think I want to replace my heat exchanger too, It seems to be very rusty on the inside.

Thanks for that link BTW!

RedGuy · 09-04-2008, 12:02 AM

Ok, I got the burner assembly, gas valve, and ignitor out today. It was a real PITA though since I could not get the exhaust stack to come off. It looks like it should just pull strait out once you undo the wing nut on the front, but no matter how hard I pull it won't come out. Anyone knwo how to remove this part? I did manage to squeeze the other assembly by the exhaust stack. My Burner is toast, rusted up pretty bad, my ignitor looks good, my gas valve had crud in the end blocking the hole. So I'm going to replace the burner, ignitor (since I got it out), and the end of the gas valve (it's like a little bolt with a hole in the end).

Also I was wondering if at this point how hard would it be to bump up to the next BTU range? Mines a 20,000BTU unit right now, can it be bumped up to a 30-34,000 unit just by changing the end of the gas valve and burner?

RV Wizard · 09-04-2008, 01:19 AM

RedGuy, You may want to consider replacing the unit with a larger furnace. You cannot just put a larger burner orfice as the heat exchanger is also larger in the larger btu furnaces. By changing the unit out you have a good warranty, all new parts, more btu's and a reliable unit for another 20 years. Otherwise, the old one could nickel and dime you to death.

RedGuy · 09-04-2008, 07:31 AM

I considered that, but I'm not quite ready to drop $5-600 on a new furnace for a 20 years old TT. Right now I'm looking at about $60 in parts, and no labor since I'm doing it myself. At worse I'll have to buy a new board, which is another $120. But I don't think my board is bad, pretty sure my burner being rusted out was the main problem. Also now that I can see into the combustion chamber better it doesn't look hardly rusted at all. I think most of the rust I got out of the unit had come from the burner assebly.

RedGuy · 09-12-2008, 09:53 AM

OK! I finally got my new burner and ignitor and put them it. As expected reassembly was just as hard as dissasembly as I still could not remove the exhaust cover. Next time I am going to drill out the rivets so I can make this thing more accessable. Total cost so far is $45 for the burner, $15 for the ignitor, and $3 for a new ignitor gasket. I'm about to go install this thing in my TT hope it works.

RedGuy · 09-12-2008, 09:14 PM

All installed and works great! Glad I didn;t go out an buy a new furnace. It lights off within a second or two.

RV Wizard · 09-12-2008, 09:38 PM

RedGuy, glad to hear that you have got the furnace going again. I trust you have a CO2 detector, and it is working properly. If not you should get one in case the heat exchanger ever goes out. Good luck and keep us posted.

RedGuy · 09-15-2008, 04:31 PM

Yep, CO detector actually.

That was one of my first purchases when I bought this trailer. I went up north this weekend, and it got chilly. Turned on the furnace, and nothing!

The blower turned on, the gas valve opened, but the ignitor never turned on. It did rain ALOT this weekend and I drove up there in the rain. The furnace worked great right before I left, but when I got where I was going after driving in the rain it wouldn't light. Luckily my A/C unit also has heat, and that saved my butt. I tried the furnace a few times with the same results and figured I probably got the board wet and fried something. It was wet inside the furnace door. Well today when I'm putting my camper away at the storage facility taking care of all the odds and ends I figured just for grins I'd try the furnace. Sure enough it fired right up!

Only thing I can figure is it dried out today. Hopefully next trip I take it'll work and I can test it out all weekend. But at least I know I can stay warm with my A/C if I have to.

RedGuy · 10-02-2008, 06:34 AM

Ok, so my funace works fine when it's dry out, but the ignitor doesn't work when it rains. The door doesn't shut real tight and there would be some water on the inside of the inner door when it would rain. There was a lousy 20 year old foam strip around the top to keep water out, that wasn't doing it's job anymore. So I got some good 1/2 inch foam rubber seal and ran it around the whole inside of the inner door, which had no seal at all. Then I also ran the foam rubber seal around the outer door in the same place as the old seal. Then I added a couple screws to the top of the outer door to pull it closed tighter. It looks alittle redneck, but I don;t want to freeze. LOL Anyways it rained the day after I did this so I went out and tried it, and it fired right up, so hopefully I've got it nailed now.