2004 trane xr14i with T8611G honeywell t stat

Problems related to residential installations.

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2004 trane xr14i with T8611G honeywell t stat

Post by ronnieredline » Sat Mar 05, 2016 10:58 am

well i will start out by saying this is a real doozie guys !!!
im licensed and only work on family, friends or my own equip.
having said that, im working on my dads house, it has 2 identical units
one up stairs and one down stairs, both are totally un related.
they were installed new in 2004 outside unit is trane XL14i 4twx4030a/1000aa
air handler is trane 4tee3f40a/1000aa , well these units havent defrosted since
2007 we think, i replaced both comp and i did it and sub cooled both of them
under ideal conditions and even sat there in a lawn chair and took my time
till i got it perfect, comp were installed about a yr apart on each unit.
they are both icing up and not defrosting at all. the brown wire is not hooked up
from T1 on either unit, i have them hooked up per the wiring diagram and all
both units icing up the same, by the diagram it says that T1 goes from the cond
unit to the T on the air handler and then up to T on the thermostat, well we dont have
a T on the stat ?? whats the brown wire looking for a common? diagram says DO NOT APPLY
all sensors tested good with ohm meter and the charts, boards are good to, put a
good used one in each unit, no change forced defrost works, also if you hold onto
ambient sensor and change delta t it goes into defrost, but it wont do it on demand.
both units are not using the tan wire and according to the wire diagram the orange
and blue wire from the reverse valve comes from the relay controlled by the little
thermistor on the board, which is controlled by the brown wire that should go to the
room stat, what can i do? ive been told to put it on x2 and then jump it to common
anybody got any ideas? 2 seperate units doing the exact same thing , wired the same and
all. its gotta be the brown T-1 wire not being used!!!
all your help is greatly appreciated, ive been on this for a week now.
please let me know
thank you

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Posts: 3
Joined: Sat Mar 05, 2016 10:20 am

- 2004 trane xr14i with T8611G honeywell t stat

Post by ronnieredline » Fri Mar 11, 2016 5:17 pm

well we have aquired a trane heat pump defrost book, the T-1 wire for our brd goes to T on the thermostat, but if you dont have a T find a X or X2 or an L terminal, as long as its under 10 vlts it will work, it does for our circuit brd according to trane.
if its over 10 vlts it will burn out ODS-A ,, T-1 is a system that reports back to the thermostat and turns on either a led or fault light, which is X or X2 and L for us was system monitor and so on.
but this still has not fixed our defrost problem on either unit and they are NOT related
some online info has told us that if the resistances of the CBS OR ODS-B is relatively close there ok, well this is simply not true
the trane book says 5% either way and no more, if it under or over 5% then replace them.
so we are replacing the CBS for now and trying it out.
i will stop back and report as to what we find or discover, that fixes the unit, even though the upstairs is NOT related to the downstairs, but both have identical problems?
i will tune back in later on.

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