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 > Atwood 8531-IV DCLP Furnace Not Working

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enblethen

Moses Lake, WA

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Posted: 11/17/19 12:35pm Link  |  Quote  |  Print  |  Notify Moderator

All drawings for thermostat shows R to W for furnace.
Hunter drawings


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dougrainer

Carrolton, Texas

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Posted: 11/17/19 12:38pm Link  |  Quote  |  Print  |  Notify Moderator

1. Jumping the 2 Blue input wires at a furnace does NOT BYPASS any Limit or safety control on a furnace
2. The 2 blue wires----ONE is output 12 volts to the tstat OR the AC control board. The OTHER BLUE wire is the down 12 volt supply from the Tstat OR the AC control board to tell the furnace to start a cycle
3. Colors other than BLUE are wiring the OEM runs from the furnace to the Roof AC control board or the Wall tstat.
4. You NEED to know what type AC brand and control you may have to troubleshoot.
5. Does the furnace 2 wires go directly to the Wall Tstat or to the Roof AC control board? THAT is needed to know to troubleshoot
6. IF you can get access to the 2 BLUE furnace wires at the furnace, you should have 12 volts on 1 Blue and nothing on the other. IF you have 12 volts at 1 BLUE then jump the blues, the furnace will come on and light and run as long as those 2 BLUE wires are jumped. IF the furnace runs and stays running longer than a few minutes, your problem is NOT the furnace but the Tstat control system.
7. IF the furnace fails to stay lit and run for a few minutes, your problem is in the furnace control and the furnace needs to be diagnois and fixed. Doug

climb.on

Minnesota

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Posted: 11/17/19 12:43pm Link  |  Quote  |  Print  |  Notify Moderator

Old-Biscuit wrote:

What Brand/Model is your AC Unit?

Need wiring diagram for the AC to understand how the DC is incorporated with your Furnace.


Duo-Therm 57915.541 Prod. No. 991760426 Serial No. 61630343


2007 Solaris T-276SR
Upgraded w/ Shocks, EZ Flex Equalizer, TST 507 TPMS, LRE Tires, LED's, Hensley Arrow.....
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BFL13

Victoria, BC

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Posted: 11/17/19 01:10pm Link  |  Quote  |  Print  |  Notify Moderator

"The 2 blue wires----ONE is output 12 volts to the tstat OR the AC control board. The OTHER BLUE wire is the down 12 volt supply from the Tstat OR the AC control board to tell the furnace to start a cycle"

So when the single white wire from the Tstat is "furnace" that is the "down" wire and it is "energized" (Tstat manual's term) with call for heat. If the Tstat has that red 12v wire, then it would be like the live "up" blue wire, and the Tstat makes the red and white connect to "energize" the white down wire?

So in that case what would happen with the furnace's live "up" blue wire? Just cap it off? Join the "down" blue wire to the "down" white wire is all that is needed?


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climb.on

Minnesota

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Posted: 11/17/19 01:27pm Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:

1. Jumping the 2 Blue input wires at a furnace does NOT BYPASS any Limit or safety control on a furnace
2. The 2 blue wires----ONE is output 12 volts to the tstat OR the AC control board. The OTHER BLUE wire is the down 12 volt supply from the Tstat OR the AC control board to tell the furnace to start a cycle
3. Colors other than BLUE are wiring the OEM runs from the furnace to the Roof AC control board or the Wall tstat.
4. You NEED to know what type AC brand and control you may have to troubleshoot.
5. Does the furnace 2 wires go directly to the Wall Tstat or to the Roof AC control board? THAT is needed to know to troubleshoot
6. IF you can get access to the 2 BLUE furnace wires at the furnace, you should have 12 volts on 1 Blue and nothing on the other. IF you have 12 volts at 1 BLUE then jump the blues, the furnace will come on and light and run as long as those 2 BLUE wires are jumped. IF the furnace runs and stays running longer than a few minutes, your problem is NOT the furnace but the Tstat control system.
7. IF the furnace fails to stay lit and run for a few minutes, your problem is in the furnace control and the furnace needs to be diagnois and fixed. Doug


Thanks for this explanation.

Furnace wires all go to the AC unit. I DO have 12v on one blue, but not the other. When I jump the blues, The fan comes on, ~15 seconds later the furnace sparks & ingnites and burns until I remove the jumper. When I remove the jumper, the flame goes out and the fan runs for a bit longer ~1min, then goes out. The furnace will continue to run as long as the jumper is in place.

When I have the jumper in place, The furnace runs regardless of the set point of the thermostat and whether or not the switch is set to "heat" or "off."

climb.on

Minnesota

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Posted: 11/17/19 01:36pm Link  |  Quote  |  Print  |  Notify Moderator

enblethen wrote:

R to W should turn on furnace at thermostat


When connecting these 2 wires at the thermostat, I only get the same click in the replay up on the relay board in the AC housing, but the furnace does not start. It's the exact same result as when the thermostat normally calls for heat.

climb.on

Minnesota

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Posted: 11/17/19 01:40pm Link  |  Quote  |  Print  |  Notify Moderator

It seems like this narrows it down to the relay or the wire between the furnace and the relay. No idea how to trouble shoot the relay. No Duo-Therm relay board with the part number 3107541.009 seems to be available.

[image]

dougrainer

Carrolton, Texas

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Posted: 11/17/19 02:21pm Link  |  Quote  |  Print  |  Notify Moderator

climb.on wrote:

It seems like this narrows it down to the relay or the wire between the furnace and the relay. No idea how to trouble shoot the relay. No Duo-Therm relay board with the part number 3107541.009 seems to be available.

[image]


This is a problem when you have no idea what you are doing. That P/N is for a Analog DOMETIC control kit. That is the Module in the housing and the wall tstat with the AC mount bolts. 3106996.022 should be the analog module only. FYI, NOBODY says Duo Therm. That term has been obsolete for over 35 years. DOMETIC is the Brand name that is used. Doug

dougrainer

Carrolton, Texas

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Posted: 11/17/19 02:22pm Link  |  Quote  |  Print  |  Notify Moderator

This should give you a total breakdown. Doug

http://www.cleggind.com/postal_tech/pdfs/AC1/3107904%5B1%5D.025.pdf

Old-Biscuit

Verde Valley

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Joined: 06/20/2009

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Posted: 11/17/19 03:49pm Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:

climb.on wrote:

It seems like this narrows it down to the relay or the wire between the furnace and the relay. No idea how to trouble shoot the relay. No Duo-Therm relay board with the part number 3107541.009 seems to be available.

[image]


This is a problem when you have no idea what you are doing. That P/N is for a Analog DOMETIC control kit. That is the Module in the housing and the wall tstat with the AC mount bolts. 3106996.022 should be the analog module only. FYI, NOBODY says Duo Therm. That term has been obsolete for over 35 years. DOMETIC is the Brand name that is used. Doug


You information would be so much better received if you were NOT so condensending in your relies.
Lighten up....good grief


Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
On the Road Debt Free April '07
Off the road still Debt Free Jan. '14

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