R&R of RV furnace

[Lakota Wolf]

Considering  its stormy weather outside,, I took the RV furnace out in between the down pours, Thank goodness for pop up canopy's.

My 92 Fleetwood 5th wheel has a Hydroflame 5330 furnace,, Atwood bought out the brand and labled it an Atwood 8531-11 model.

32,300 b.t.u. (4 ducts).

It wasn't rocket science to remove it,,, I started by disconnecting the thermostat wire, (red and white wire sleeved in a brown coated wire),

then disconnecting the 12 V power supply,, which was a white wire and Black wire,, The rest of the harness stays with the furnace unit,

After removing 14 screws that holds the access panel on the side of the RV,, I used a putty knife and slowly peeled the panel frame and door away from the side of RV, seperating the Butyl tape and salvaging it. Before the panel can be completly removed, it has (6) tabs that go from the furnace housing to the face plate that need to be bent straight for the panel door to be slide off.

I disconnected the (4) duct tubes, and the gas line, AFTER turning off the propane at the tanks. On the front of the furnace housing where gas lines goes through is a plastic slide plate that goes around the gas line making a good seal from the inside to the outside of the coach. Weather seal.so to speak.

I slid the whole unit out and took inside the RV,, (yea yea,, I know what your thinking,) I had a card table with a tarp under the table and a towel across top of table, so the work area would catch anything that came out of the furnace, I was fortunate, no wasps,bees, elephants or ninja squirrells, I had to take out 4 sheet metal screws holding the control regulator, and 1 screw that held the end of the squirrell cage,(blower motor cover). The whole unit slides back and you can disconnect the (6) electricl plug ins, then continue removing the control regulator, It did have the usual dust bunnys and slight crud around it,,, But was lucky not having the notorious nest of mud daubers. After taking the control unit out, I had to revove the gas orifice which involved removing (2) screws and it comes out of the (squirrle cage cover that came off with the regulator.) On the cage cover is the dispersion horn,,about 8 inches of steel tube tapered down to about 2 inches across at the end and has built in screen,

This piece is all stainless steel and was in excellent shape, The gas orifice had a little crud build up on the end of the nozzle, and using a micro cleaning wire,(used to clean gas welding equiptment nozzles) I made sure the orifice was clean, and used a bright flash light to see if the light went through all the holes,(has 3 tiny holes in this particular orifice), I took a vacumm hose and sucked out the furnace tubes after turning the furnace assembly upside down and every which way,, not much came out,,,, was very lucky there,,,, you usually get a colony of mud dauber nests that have been vacated.After double checking everything, especially looking for wear spots or burn spots I then cleaned the electronic ignition probes lightly with ultra fine steel wool and wiped them down,, I re-assembled everything, and re-installed the unit,, Re connected the wires and gas line,, checked for leaks and flipped the ole switch,, VIOLA,,,, fired on first shot.

*Note,, when putting the faceplate and door back on, make sure all 6  tabs go through the slots on the door cover and bend back down before putting mounting screws back in. After running several cycles,, the thermostat is off by 2 degrees, BUT,,, I can live with that.

I couldnt take pictures outside in the removing and reinstallation process due to the rain and the indoor pictures I took came out either to dark or over white from the flash,

[Lakota Wolf]

Thanks for the heads up David,,,The screen was in better shape then I would have imagined,, and Ive looked at a couple other Atwoods and their screens resembles more like a deflector plate,, like a V shape design. And here in Texas,, those Mud daubers and yellow jackets are bad news with any type of opening anywhere on an RV.. Ive even seen a nest inside of a cracked clearance light.

Hope you and yours have a safe holiday season and a Merry Christmas to you to.

[david craft]

safeguard that burner screen. last i checked, atwood quit making those on older 8500 series. its too bad to because they are great and i still can get motors. low gas pressur or a tired motor will cause the flame to burn lower into the burner screen and toast them. the sail switch on the blower housing is prone to get bent a little and hang up on the housing. make sure that doesnt drag. they make a good screen for the exhaust duct and it would be advised in areas where mud daubers and paper wasps frequent. good seeing youall still at it...merry christmas

[Rich Thomas]

Nice job Lakota, now that you have it fixed Texas will probably go through a heat wave and you won't have to use it.

[Russell E Johnson]

Great write up Lakota. You must have been in a serious way because you didn't give this furnace article any of the humor you are so famous for. Furnaces are not too complex, perform the annual maintenance and they will do their job faithfully for many years.