Community Forums

Jayco_Beamer · 01-22-2021, 05:46 PM

Hey guys. I'm having a problem with my atwood heater. After discovering a water leak from my hot water tank, my furnace started smoking and smelling bad outside. I removed the vent pipe and discovered the pipe was nearly clogged shut. After removing the unit, I took it to a repair shop who charged me 150 to "clean it out" and claimed they had it running for 20 minutes and it was good to go. After reinstalling it, it wouldn't light. I found a diagram for it and removed the burner. there was mounds of muddy soot on the burner and built up really bad in the chamber. I snaked it out, cleaned the burner, and reinstalled it. When it lit, it stayed lit. The problem is it's shooting sparks and steam out of the exhaust port. Do you guys think it's worth attempting to repair, or would it be better to replace the entire unit? we bought this Jayco back in October used (2018) and the furnace seemed to run fine until we found the water leak and the temps dropped into the 20s. Thanks in advance.

Old-Biscuit · 01-22-2021, 05:55 PM

The problem is it's shooting sparks and steam out of the exhaust port.

Steam would be from being WET
Sparks...that is probably 'sparklers' from the SOOT

Need to PULL it back out
Disassemble so that you have JUST the Heat Exchanger
THEN POWER WASH THE HEAT EXCHANGER....soot has to be WASH off/out to remove it
(Self serve car wash....rinse thoroughly when done washing)
Drain it and then blow air thru it to dry it completely

Make sure burner assemble is CLEAN

It would be VERY Helpful to post Year/Model of that Atwood Furnace

And fill out Signature Line with Year/Mfg/Model of RV
User CP....Setting & Options----Edit Signature---SAVE Signature

Jayco_Beamer · 01-22-2021, 06:12 PM

Dometic/Atwood AFMD30. I will have to pull it back out and darn near disassemble the entire heater to powerwash. I may just see about getting another heat exchanger.

hclark6345 · 01-22-2021, 06:22 PM

This is not something to save money on. A fire from a faulty furnace will kill you quickly, and a carbon monoxide leak from a faulty heat exchanger will kill you a little more slowly. If you are not positive it is fixed correctly, replace it.

Old-Biscuit · 01-22-2021, 06:54 PM

Quote:

Originally Posted by Jayco_Beamer

Dometic/Atwood AFMD30. I will have to pull it back out and darn near disassemble the entire heater to powerwash. I may just see about getting another heat exchanger.

Would have to "darn near disassemble the entire heater " to replace the Heat Exchanger

New one ---part number 35710
$90-$100 depending on vendor

Whoever was previous owner had to run that with a bad flame (Fuel Rich===SOOT) to coke it up that bad

Jayco_Beamer · 01-23-2021, 06:41 AM

Quote:

Originally Posted by Old-Biscuit

Would have to "darn near disassemble the entire heater " to replace the Heat Exchanger

New one ---part number 35710
$90-$100 depending on vendor

Whoever was previous owner had to run that with a bad flame (Fuel Rich===SOOT) to coke it up that bad

Yeah, old biscuit. After doing some research I figured out this thing must have been short cycling all along. The heater never would get really hot nor run longer than 10 minutes. It did keep us warm until it blocked up too bad to run. I'm gonna call a pro out here to have a look. Better safe than sorry, but I am kinda curious if that crap would burn out and dry after a few cycles. Not gonna a try it though. That thing was putting off quite a show.

Old-Biscuit · 01-23-2021, 10:16 AM

Quote:

Originally Posted by Jayco_Beamer

Yeah, old biscuit. After doing some research I figured out this thing must have been short cycling all along. The heater never would get really hot nor run longer than 10 minutes. It did keep us warm until it blocked up too bad to run. I'm gonna call a pro out here to have a look. Better safe than sorry, but I am kinda curious if that crap would burn out and dry after a few cycles. Not gonna a try it though. That thing was putting off quite a show.

Sooted up.....more heat====coking that is very difficult to remove

Also......birds nests. Those will burn off but 'throw sparks'?

Short cycling------THAT is due to lack of proper airflow
Obstructions (debris/etc) in exhaust
Which probably was the primary issue and lead to the incomplete combustion which resulted in the sooting

Course could be other issues...but based on you description heat exchanger needs thorough cleaning (burner and orifice while at it )

Jayco_Beamer · 01-24-2021, 07:52 AM

Well, I've been cycling it since. it has stopped throwing off sparks, steam, and smoke (which seems to be the soot and built up crap). When i ran a full cycle this morning, it started burning clean and puts off ALOT of heat. It didn't take long to heat up the trailer. The hvac guy cant make it out until friday. It's supposed to freeze this week. I'm gonna keep an eye on it and hopefully it will get us by with limited use until then. there are no strange odors inside and no alarms are going off. The combustion chamber was nearly clogged shut and the burner was 60% covered in an inch crap, which I cleaned as best i could with what i had. The thing that ticks me off is the buck thirty I paid the "repair guy" to clean and diagnose it. It literally took this little ol brand new to RVing guy 20 minutes to pull up a diagram, remove the heater and remove the burner to figure out why it wasn't firing. when that jacknut suggested it was a loose wire, I hit the roof, said screw it, and dug in. I learned plenty about the system and repair guys. The new guy actually knows what a combustion wheel is. Fingers firmly crossed.