# Ruud Furnace intermittent problem



## dbh (Dec 31, 2009)

Ok 50 ppl viewed this post and not one person has a clue what might cause this problem...hmm think i might be in the wrong place.


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## yuri (Nov 29, 2008)

Read the error code info which may be on the back of one of the doors or in the electrical diagram. Post the model and serial # and pics of the unit with both doors off so we can recognize it.


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## dbh (Dec 31, 2009)

Ok can not find the model number but here are some pictures.


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## hvac benny (Dec 29, 2009)

i'm not familiar with this make of furnace, but from your pics, i can see where the flame rod attaches to the burner, but can't see it IN the flame. follow the black wire under the burner, and see the rod is in the flame. if it is, take it out with a 1/4 driver and clean it with fine steel wool ( not sandpaper).


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## dbh (Dec 31, 2009)

hvac benny said:


> i'm not familiar with this make of furnace, but from your pics, i can see where the flame rod attaches to the burner, but can't see it IN the flame. follow the black wire under the burner, and see the rod is in the flame. if it is, take it out with a 1/4 driver and clean it with fine steel wool ( not sandpaper).


Benny thanks for your reply...I did that last season, does this have to be done every year?


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## dbh (Dec 31, 2009)

Here are some of the flame sensor.


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## hvac benny (Dec 29, 2009)

it looks like it could use a cleaning. not a bad idea to do this before the heating season every year, but just lightly.


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## dbh (Dec 31, 2009)

hvac benny said:


> it looks like it could use a cleaning. not a bad idea to do this before the heating season every year, but just lightly.


Would this cause the unit to work intermittently like that? The furnace will work fine for sometimes days and then it will get cold in the house and i will notice that it isn't kicking on...but soon as i reset the power to the furnace it works fine again.


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## Marty S. (Oct 31, 2009)

The board will lock out if flame is not sensed. Clean the front of the burner also, that's half of the flame proving operation.


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## spark plug (May 5, 2009)

dbh said:


> Ok 50 ppl viewed this post and not one person has a clue what might cause this problem...hmm think i might be in the wrong place.


OK. Leave and then come back! You'll realize that there are none better than this one. If you provide the correct and pertinent information, I will bet you that your problem will be resolved. One or more of the experts who frequent this blog will have an answer! (No matter what) Don't Drink and Drive, Ever!!!


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## spark plug (May 5, 2009)

dbh said:


> Benny thanks for your reply...I did that last season, does this have to be done every year?


Apparently yes! BTW. You have a ton of technical information on the inside wall of the furnace. Why didn't you take a close (readable) picture of those data?!:furious:??


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## dbh (Dec 31, 2009)

spark plug said:


> OK. Leave and then come back! You'll realize that there are none better than this one. If you provide the correct and pertinent information, I will bet you that your problem will be resolved. One or more of the experts who frequent this blog will have an answer! (No matter what) Don't Drink and Drive, Ever!!!


I thought it was too SP but after 50 views and not one reply i thought that it might just be...I have had nothing but problems with this Ruud furnace since i bought this house 5 years ago...as i said in my first post i have replaced just about every part that you can replace in this furnace and i am still having problems with it...now if cleaning the burners and flame sensor fixes this i will be very surprised and delighted at the same time. I will post my findings after i clean everything tomorrow....and i agree with you Don't Drink and Drive.


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## dbh (Dec 31, 2009)

spark plug said:


> Apparently yes! BTW. You have a ton of technical information on the inside wall of the furnace. Why didn't you take a close (readable) picture of those data?!:furious:??


I have trouble shot this unit since day one SP and yes you are correct there is a ton of technical information on the inside of this unit and it still does not tell me what is causing this intermittent problem...if i was just a limit switch that opened up or a fuse or loose wire or whatever no problem i wouldn't even be posting this problem.


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## hvac benny (Dec 29, 2009)

Sometimes the flame sensor will cause the furnace to lock out completely, and other times it's just dirty enough to be an intermittent problem.


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## hatrabbit (Jan 3, 2010)

It seems like everyone here is convinced it's got to be the flame sensing circuit, could it be something else? For example, could it be going into lockout due to the limit control tripping repeatedly (dirty filter?). Or any of a number of other things?


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## yuri (Nov 29, 2008)

YES. He needs to sit with and run the unit with the lower cover off and tape the door switch closed and monitor the LEDS to see if it is tripping on the pressure switch etc. Cycle it on/off a couple dozen times and the problem usually shows up. Patience is a virtue in our biz.


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## dbh (Dec 31, 2009)

yuri said:


> YES. He needs to sit with and run the unit with the lower cover off and tape the door switch closed and monitor the LEDS to see if it is tripping on the pressure switch etc. Cycle it on/off a couple dozen times and the problem usually shows up. Patience is a virtue in our biz.


I have taken the door switch out along with the power switch...i have watched the LED's and have cleaned the AC coils along with the exhaust vent...now the exhaust vent was pretty dirty...but i am still having the problem...when the unit flames up i get two solid green lights and a blinking yellow...when the unit locks out or doesn't turn on i have one solid green and a blinking green until i reset the power to the unit.


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## Marty S. (Oct 31, 2009)

Is there a chart in the furnace or on the doors showing what that light set means?
Not positive but I think there should be a metal cover over the black box holding the circuit board. I think the codes are listed on the inside of that missing metal cover


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## dbh (Dec 31, 2009)

Marty S. said:


> Is there a chart in the furnace or on the doors showing what that light set means?


Not that I can find...schematics is anot it.


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## Marty S. (Oct 31, 2009)

Model number should be on that label over where the gas pipe comes in. We can probably find the codes with a model number.


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## yuri (Nov 29, 2008)

The yellow LED indicates low flame current when it flashes. The codes are usually in fine print on the electrical schematic or the instructions that came with the new board. That unit has a history of pressure switch tripping problems. Sit there with your multitester on the switch and see if you get 24 volts across which indicates it has tripped. Cycle it 2 dozen times. Check the port on the inducer fan where the switch hose attaches for blockage, clean it with a small bit or paper clip.


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## dbh (Dec 31, 2009)

Model number is ugdg 10 eamer


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## dbh (Dec 31, 2009)

I Get 28 volts across the pressure switch when the unit is cycled off..two green solid LED`s ...unit turns on voltage at switch goes to 7mv then to 24mv...still getting the blinking yellow LED.


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## dbh (Dec 31, 2009)

Can not find the paper work that came with the mother board for error coding. i still have the box the control board came in and it is part number 62-24084-82 Protech


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## yuri (Nov 29, 2008)

Did you clean the flame sensor with some fine emory paper/steel wool and the face of the burner it sits in front of? If not do so. There needs to be proper grounding from that circuit board to the chassis of the furnace. Some of those boards had a ground screw or wire and that may be loose/missing?


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## dbh (Dec 31, 2009)

yuri said:


> Did you clean the flame sensor with some fine emory paper/steel wool and the face of the burner it sits in front of? If not do so. There needs to be proper grounding from that circuit board to the chassis of the furnace. Some of those boards had a ground screw or wire and that may be loose/missing?


After pulling the burners out and cleaning them and the flame sensor and everything else i could see i get a solid yellow when unit is operating....so hopefully that was it...thank you all for your help...here's to a warm house.


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## spark plug (May 5, 2009)

Marty S. said:


> Is there a chart in the furnace or on the doors showing what that light set means?
> Not positive but I think there should be a metal cover over the black box holding the circuit board. I think the codes are listed on the inside of that missing metal cover


...Or, you can go online or call the manufacturer with the model # and they will send you all the relevant information. (No matter what) Don't Drink and Drive, ever!!!


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## spark plug (May 5, 2009)

dbh said:


> Model number is ugdg 10 eamer


that model # sounds like it came from outer Mongolia or some other place in the now defunct, former USSR!:laughing:!


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## dbh (Dec 31, 2009)

spark plug said:


> that model # sounds like it came from outer Mongolia or some other place in the now defunct, former USSR!:laughing:!


That would explain a lot SP...24hrs and no lock outs...:thumbup:


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## sean daly (Dec 9, 2020)

I have a Rudd it was not firing up after inducer motor ran for a minute The light blinked twice replaced both pressure switches. The furnace ran for a couple day and the same scenario. shut it down for a couple hour started up. Run for a couple days same thing. I remove the drain tube and blow it restart and runs for a day or two. Have had a technician here twice. baffled


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