We've been running the Atwood 8535 front furnace in the mornings for the past few months. New in 07, it now makes a "groaning" sound and will not fire. I assume the motor is toast, my question is it looks likes it comes out from the outside, but can the motor be pulled without the removing the whole assembly? If the furnace has to come out, do I need to remove the fold-out bed to undo the hoses or is there access underneath? I'm not exactly in RV tech city, so my thought is to order a fresh furnace and find someone to help me pull the old & re-install new. We're expecting a storm, but have our good old liquid radiators & the stern furnace to help us "survive". Thanks for any advice, M
Here is a Youtube and it looks easy. Click on the words "YouTube video" not the picture.
http://www.youtube.com/watch?v=d7YTOcSPOyI
Mike,
Before considering replacing the motor, I would oil it. It has bushings, not bearings. Use a light, non-detergent oil such as sewing machine oil.
Everything can be done from outside-- accessing the motor, replacing it, etc.
Thanks to you both! Brett, can I oil the motor without pulling it. (I wish I had smaller hands in situations like this). :'(
Yes. A drop of oil at a time on a long screwdriver to either end of the motor (between motor and fans. Oil will wick into the bushings. Worse case pull it and lubing would be more effective, but more work. Start with easy.
What would we newcomers do without this great forum? b^.^d
What about using one of those long nose oil cans, either the pump type where you squeeze the handle on the other side of the small juice size container, or one of the long tube where you push on the bottom of the can to get the oil to "burp" out.
Slow and lightly let the oil out.
Damn! I used to have one of those. Oh well, that's what Amazon is for. ^.^d
Sure, an oil can with long spout would work fine-- just make sure it has light-viscosity, non-detergent oil.
But I have often just used a long blade screwdriver and put oil in a drop at a time.
Mike lol had the same thing happen to our bedroom heater. Did the oil.thing and it helped.but then it got crazy noisy.so it happen to get a motor from Ken and replaced here at camp Verde.it was not that bad of a job. I found the video on YouTube and it took a little time. Make sure you have a 1/8 Allen wrench about 6 inches long for the set screw on the fans.
Not sure how long of a reach is needed, but they sell sewing machine oil in bottles with extending spouts. Local JoAnn fabrics or sewing machine shops should have them.
Dritz? Machine Oil - 4 oz | Jo-Ann (http://www.joann.com/dritz-machine-oil-4-oz/2739944.html)
They also make one with a 14" reach.
Go to Ace Hardware and ask for a zoom spout turbine oiler, the oil is made for motor bushing.
Ho ho, we have one just down the street, thanks, Bill ! ^.^d
@Andy,
Glad you got it in! I was going to send you a link to that YouTube video. Looks like I don't need to now. :)
see ya
ken
Thank you Ken , she works like a new one.Safe travels my friend.
UPDATE.....Just for grins, I tried the furnace this a.m., it worked, but would not re-cycle. I remembered my Suburbans did the sorta same thing and was solved by replacing the card, I ordered one (good to have a spare, anyhew). News at eleven. M
We used our Amazon Zoom Spout oil to oil our roof air conditioner motor bearings. It should fix a noisy furnace motor. Our furnace motor comes out, with some effort.
Mike,
Along with the Zoom Spout Turbine Oil I would also recommend the Zoom Spout Rust Buster. It's usually sold where you find the oil. It's thin like water and is some amazing stuff for loosening up nuts, bolts, screws, shafts, etc. I use it all the time. 4 Oz Zoom Spout Rust Buster | HD Supply (http://hdsupplysolutions.com/shop/p/4-oz-zoom-spout-rust-buster-p111530)
Jerry
Just talked with Atwood rep, he checked and said the motor in my 8535 IV DCLP (new in 07) is "permanently lubricated" and the motor would sound like one of my ex-girlfriend's should it go bad, not the "buzzing" I'm having. He agreed with me that it's most likely the card, we'll see! M
Mike,
If you think it is the control board and you have two heaters, swap the control boards, if it's the board the problem will move to the other heater.
JD
I'll have a fresh board in a few days. Furnaces are different makes, but the boards look the same. Will check with my favorites: Dinosaur Electronics Home. High quality circuit boards for RV appliances. (http://www.dinosaurelectronics.com) to see if the "universal" fits both furnaces. They make a cool tester that I might invest in. Thanks, John ^.^d
@Mike,
Wish this had come up while we were there. I have the controller board I pulled out of my 8535 when it died. Tried to sell it on ebay but no bites. If you want it pm me your shipping address and I'll send it.
see ya
ken
Thanks for the offer, Ken. I believe it's called "Coach Karma", where something goes out when you most need it. I've not had the coach long enough to have spares on board, but it's time . ^.^d
UPDATE: Decided to check the voltage to the existing board with my trusty VOM , pulled the main power connection from the board to measure, found 13.78 volts, o.k. Here's the kicker, plugged the wire back in, hit the switch and on came the furnace and worked as advertised , this morning cycled correctly! Could have had a corroded connection in the hot or jiggled another wire when I moved the card out to measure. I'm still going to replace the board, but will clean the wire lugs and next time (there will be), I'll pull the wire connectors and clean the board connections. I'll keep this board for a spare.
Sometimes you need to tighten the connector by pressing with a small screw driver on individual female connections.
Bill
FINAL UPDATE (I hope) New card worked for a few days and the furnace choked again. VOM showed 11 volts from battery, but zero when I put a load on it. Hmm...Pulled & cleaned the fuse in the rear 12 volt, still no fire-up. Finally opened the gen bay below , and, after tracing the hot from the furnace, found this wire (the hot) coming from gen set power. As you can see, IT HAD GOTTEN CRISPY ! Put in a new connector w/fuse (never even found a fuse in the existing mess), and the furnace was back in the biz! I'm wondering if there were previous electrical problems and the yellow "shunt" wire was plugged into the gen to get power for the furnace? Saw no paperwork from Brett, so he's off the hook. ^.^d
Mike,
That certainly explains the lack of power to the furnace.
And because low voltage (voltage drop in long, small-gauge wire from back fuse box to furnace) when dry camping is a problem for furnaces (low voltage= slower fan= sail switch does not stay closed= furnace stops working), using heavy gauge wire from batteries (that very ample hot for generator in the next bay) is a common "better source" for the furnace power. And fused as you verified.
Now, the question is what caused that fuse and fuse holder to melt??? Nothing else in that area show signs of overheating. So, check the short run from fuse to furnace for any place where the positive wire could have chafed through to ground. Even then, it is bazaar for the fuse holder to melt before the fuse blows.
I have seen this happen when the fuse gets a bad connection and the resistance builds heat on the power side of the fuse holder so the fuse does not blow.
Could be an anomaly, I doubt it. My thought, after searching thru the coach wiring and noticing the ATS has been replaced, as well as the shore power connections (male & female) in the wet bay, I'm thinking the coach took a huge spike at one time, possibly with both ACs on and the ATS tried to fire the gen set, trashing the furnace fuse. Now, whether it was off the pedestal or someone overloading the 50 amp system, no clue. If the ATS took a hit, it should have blown the furnace fuse, which it mite of, but maybe fused the connections together for working/not working, depending on the load. That is "Leary's Theory", at this point in time. :-\
Chuck,
Mike may be able to find the paper work on it, but as I recall, that is about a 3' run of 10 gauge wire. 20 amp fuse if memory serves.
I think Craneman may have hit on it-- corrosion in fuse holder caused resistance, caused heat..... Kind of hard to tell after the fact, and no sign of water intrusion, corrosion, etc on any other near-by generator parts.
Anyway, glad you found and fixed it, Mike.
I recently picked up several of these wired fuse blocks, all of which had 30 amp fuses. Of course, they can be pulled and any size could be inserted. How does one know what size fuse is needed for a given circuit?
Thanks,
Trent
Trent,
Two basic considerations:
1. The fuse is there to protect the wire-- fuse should be speced to blow before overheating the wire.
2. Adequate wire size and fuse size so no significant voltage drop between source and appliance. I generally use a 3% voltage drop table: Marine Wire Size and Ampacity | West Marine (http://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity)
3' of 10 gauge wire can handle a lot more than 20 amps, but 20 amps is plenty to insure no voltage drop in fuse or wiring to the furnace. Said another way, unless the fan motor seizes up or some other major issue, 20 amps is well-more than the furnace will draw. And 3' of 10 gauge wire is certainly not a limiting factor.
30 amps is a lot! Not being able to find the fuse on my blown furnace connection, I threw in a 20 amp.
Mike,
20 is a perfect size. Again, if the it blows, there is either a dead short (nick in hot wire touching bare metal, for example) or a seized fan motor. Have not looked at that furnace's electrical diagram, but very likely it has its own fuse to protect in case of motor seizing.
If the fuse or fuse holder is melted:
In my experience of over 30 years as an electrician, if the fuse is sized properly for the fuse holder and the wire..... It is almost always a bad or poor connection between the fuse and fuse clips or the fuse holder terminal and wire.
To use Brett's term: said another way, melted because of heat, heat created when current flows across a resistor ( resistance ) the fuse link will melt at its set current, but the heat generated at the clips or "stabs" may melt a plastic holder before the internal link gets hot enough to "open" the circuit.
Circuit doesn't have to have an "over current" situation for this to happen.
I have bought many of those fuse holder on the last boat I owned. I went thru so may of them I always carried a spare and had quick connects on them so I could change them out. They say they are rated for 30 amps and have @ 10 gauge wire going to them but I am thinking the connector between the wire and the fuse is not a good connection. I had tried everything to make them live thinking the connection between the fuse and holder becomes corroded but after going thru so many of them, I just think they are cheap.
Someone asked wire and fuse sizes. Here is good rule of thumb. There are exceptions
#14 gauge wire 15 amps
#12 gauge 20 amps
#10 gauge 30 amps.
The above is the max the wire can carry before bad things start to happen. In reality you want to fuse no more then above but aprox. 25% more then what the device / circuit needs. That is why you may see a 5 or 10 amp fuse on a 14 or 12 gauge wire.
Last point I want to make is as the voltage goes down the current (amps) goes up. So if a fuse blows it could have been caused by low voltage.
Thanks all! My brother-in-law (Fluke engineer) gave me this for a wedding present, made me lotsa $$$. Now, I gota remember how to use it!
Mike as you well know when a problem arises and gets posted on this forum more help pours in than you can get at any rv dealer. When I read the various issues that come up everyday its amazing the knowledge thats in this forum. Well as you always say time for a cold one.
Yup, roger that! One of the great things about this forum, is something one had not thought of, is posted! b^.^d