# Armstrong Ultra SX-90



## Leo D (Feb 12, 2008)

*Armstrong Ultra SX-90* 
Need help too:
My Armstrong Ultra SX-90 Furnacehas a problem:
here is what happens
1 power vent blower goes on
2 hear a click and ign lights and burner lights
3 after a second hear a click and burner goes off
4 after another second burner lights again and then click goes off
5 when I shut off power to unit and reset, it might work for a cycle or 2
Thanks for any help


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## hf05 (Mar 14, 2006)

lazy [ dirty ] pilot flame not impinging on sensor and or sensor itself


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## Leo D (Feb 12, 2008)

thanks, I'll try that


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## tdavis (Feb 1, 2008)

*emery cloth...*

our HVAC guy usually hits the flame sensor with a light emery cloth and it fixes the flame sensor problem...


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## Leo D (Feb 12, 2008)

Thank you all 
Here is what I did.
1 Cleaned flame sensor lightly with a nail file, very hard to get at.
2 Then I saw a burnt mark near a resistor on the curcuit board and start to clean and wiggle it.
3 replaced covers and reset unit and has been working for the last 18 hours


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