Atwood 8940 Iii Dclp Troubleshooting
Atwood Model 8940-iii-dclp Parts
Atwood 8940-iii-dclp Parts

2004-11-03 17:10:43 UTC

Hi. I have an Atwood Excalibur 8500 III hydro flame furnace. It comes on
and the burner ignites but it won't stay lit. It 'attempts' to light the
burner several times even though it is actually lit and then it just shuts
down the gas (propane) and the blower continues to run (until we freeze to
death, turn it off, or the battery runs down).
According to Atwood's web site there are many things that can cause this
problem including low gas pressure, bad circuit board, bad flame sensor, too
much static pressure, not enough static pressure, bad wires, loose blower
wheel etc. I found that the blower housing had a missing screw which would
cause low static pressure. I replaced the screw and the furnace worked
fine--for a while. Then it started doing it's thing again.
I have not tested the circuit board, the gas pressure, or the static
pressure as of yet mainly because getting all of the needed equipment to do
this would probably cost as much as a new furnace. I have checked the sail
switch, checked the exhaust for obstructions, checked for loose connections
etc.
I would like to know before I yank the thing out and take it apart if there
is a common problem with these furnaces that can cause this particular
problem. I found an aftermarket circuit board but it costs $150 and it says
that after two failed attempts to light the furnace it shuts down
permanantly. Sound rather final. Also sounds like maybe you need to buy
another $150 board if it shuts down. But at least it doesn't keep the
blower running ;-)
Thanks

Atwood 8940 Iii Dclp Troubleshooting

Furnace won't ignite

Email Support Form, Troubleshooting tips, Flowcharts, Pinouts, Manuals and Instruction sheets, FAQs and on-line resources. Warranty Info Information about our 3 year warranty and return policies on our circuit boards and 1 year warranty for Testers. Online Sales Info. The older model is called the Excalibur 8900 III, and it runs on considerably more power — either 35,000 or 40,000 BTU. Their unique designs are similar, though the III has a slightly taller profile at 9-1/8″ and is generally more well-suited to industrial purposes. Nonetheless, an RV owner seeking more power can buy one online for $700.

Atwood Model 8940-iii-dclp Parts

Atwood 8940-iii-dclp Parts

NEW
I found that my atwood 8531 furnace would not ignite unless I pounded on the side of the furnace. After doing some research and reading many blogs I took my furnace apart and looked at the control board. Nothing was burned on it and the green light was blinking once and then again 3 seconds later. I looked up the codes and it said something about air blockage. There was nothing in line of the fresh air intake. When this happens it is most likely the sail switch. The sail switch tells the unit that there is plenty of air flow and it is safe to continue firing the furnace up. The furnace is rated to be safe and not ignite if the blower doesn't produce enough air flow(70%). The sail switch is located on the underside of the blower motor (squirrel cage) housing. The switch is held in by two screws. It has been known for these switches to burn out and not allow the furnace to work. I called atwood and they said that because this furnace was discontinued that there was no replace part listed for the sail switch. I was told I would most likely have to purchase a new furnace. I went on amazon and found this switch, Atwood 36680 Sail Switch. The switch costs me $4.95 and was sent in three days. I put this switch in and the furnace fired right up. Please do this before taking your furnace in to be fixed. This was an easy fix and saved me hundreds of dollars. Good luck. Any questions you can contact me at mmd2791@yahoo.com. No charge for what I know. Thanks