# Trane XL1200 inside blower won't work



## John1 (Aug 10, 2011)

My blower on my furnace (Trane XE90) won't come on when the A/C (Trane XL1200) is on.  If I turn the A/C off and put the fan to manual, the fan comes on with no problem.  The condencer on the A/C unit will run, but not the inside fan on the furnace.  Do I need to replace the board?  Need help


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## kok328 (Aug 10, 2011)

Possibly a problem with the thermostat.
As far as I know, the thermostat will send a signal for fan through the same relay on the board when switched to fan "on" versus fan "auto".


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## paul52446m (Aug 10, 2011)

John1 said:


> My blower on my furnace (Trane XE90) won't come on when the A/C (Trane XL1200) is on.  If I turn the A/C off and put the fan to manual, the fan comes on with no problem.  The condencer on the A/C unit will run, but not the inside fan on the furnace.  Do I need to replace the board?  Need help



Most of the electronic boards today, The green post is for manual fan runs the fan on a low speed like the heating speed. When you turn on cooling, the power comes back to the y post which goes to the condenser and also to a different relay that starts the blower on a faster speed. So i would say you have a bad board.  Paul


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## John1 (Aug 11, 2011)

I went and bought a new one and replaced it, but that wasn't the answer.  Same issues,
thanks for suggesting


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## John1 (Aug 11, 2011)

kok328 said:


> Possibly a problem with the thermostat.
> As far as I know, the thermostat will send a signal for fan through the same relay on the board when switched to fan "on" versus fan "auto".


Paul,  Thanks for the insight.  How much of a problem is it to change the board?  It is the UNIVERSAL HOT SURFACE IGNITION CONTROL MODULE (50A55-843) that needs to be replaced.


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## paul52446m (Aug 11, 2011)

John1 said:


> Paul,  Thanks for the insight.  How much of a problem is it to change the board?  It is the UNIVERSAL HOT SURFACE IGNITION CONTROL MODULE (50A55-843) that needs to be replaced.



If you can let the board hang on the wires and then put the new board on furnace , then install one wire at a time. If you get those wires crossed you will have a real problem. Paul


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## paul52446m (Aug 11, 2011)

John1 said:


> Paul,  Thanks for the insight.  How much of a problem is it to change the board?  It is the UNIVERSAL HOT SURFACE IGNITION CONTROL MODULE (50A55-843) that needs to be replaced.



Can you send me some pic. of your controls. 
[email protected]     Paul


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