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I have a trane xl 1200 high heat pump I changed the themostat with a honey well rth 7500, all wires attached per the heat pump wiring instructions except for the brown wire from the old "T" terminal. nothing comes on. what should I do?

Submitted: 238 days and 11 hours ago.

Category: HVAC

Value: $15

Status: CLOSED

Hi,

The old T terminal was for an anticipator on a mechanical stat , it doesn't need to be connected to the new one.

I need to know which terminals on the old one lined up with the new one. It is not a straight forward change out if your old one was a Trane stat. Let's verify what you have first and make sure it isn't a wiring problem before moving on.

Thanks

Mark

Accepts:
Expert:	Mark Henley
Pos. Feedback:	99.2 %
Answered:	3/28/2009

Journeyman Technician

UA Journeyman Pipefitter , HVAC, Refrigeration, DDC controls. 26 years.Commercial & residential

Posted by Mark Henley 238 days and 10 hours ago.

Info Request

Hi,

Or , if I know which which wires were on which terminals on the old stat. I can tell you where to land them on the new one.

Thanks

Mark

238 days and 10 hours ago.

Reply

        WIRES ARE AS FALLOWS
        WIRE      TERMINAL
                 JUMPER TO R
          R           R
          O           O/B
          Y           Y
          G           G
          B           C
                      L
          X           E
          W           AUX

Posted by Mark Henley 238 days and 9 hours ago.

Answer

Hi,

OK, thats the right way. We need to see if we have 24 volts anywhere.

Do you have a volt meter ? if so check for 24 Volts at the C and R terminals.

Also if you can just switch the fan on at the stat , you can do this with the fan switch moving it to the ON position. You may have already tried that.

If none of that works you have probably blown the low voltage fuse if present or blown the transformer in the air handler. Make sure you have power on the air handler.

Thanks

Mark.

238 days and 8 hours ago.

Reply

I went so far as to replace the old themostat it does the same thing I hear a humming noise or buzzing coming frome the blower unit

Posted by Mark Henley 238 days and 8 hours ago.

Answer

Hi,

The humming is probably the transformer overloading due to a direct short. Don't leave ti go like that or we will need a transformer. if we don't already do.

At the stat disconnect the wire on C and see if you still get that hum. Let me know,

Thanks

Mark

238 days and 8 hours ago.

Reply

still hums with the wire on or off

Posted by Mark Henley 238 days and 8 hours ago.

Answer

Hi,

What we have to do is disconnect the low voltage wires at the air handler.

Disconnect all of them , they should be terminal-ed somewhat like the thermostat is.

1.) Disconnect them and make sure they are labeled or some method of knowing where they cam off of.

2.) Once that is done jump out the R and G terminals at the air handler where you just removed the wires and see if the blower starts.

This will let us know if we still have a usable transformer.

Thanks

Mark

238 days and 8 hours ago.

Reply

tried that it still hums

Posted by Mark Henley 238 days and 7 hours ago.

Answer

Hi,

OK , it sounds like you need a transformer.

Thanks

Mark.

238 days and 7 hours ago.

Reply

what do you think that will run or how hard a task isthat?

Posted by Mark Henley 238 days and 7 hours ago.

Answer

Hi,

A transformer is about 50 dollars and it isn't very hard to change if you get the matching one. If you get from a Trane dealer they should be able to get you the exact replacement. If you have a service call done it will probably run you around 150.00 to have it repaired.

Thanks

Mark.

238 days and 7 hours ago.

Reply

thanks for your time you were very helpful

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Question

I have a trane xl 1200 high heat pump I changed the themostat with a honey well rth 7500, all wires attached per the heat pump wiring instructions except for the brown wire from the old "T" terminal. nothing comes on. what should I do?

Accepted Answer

Info Request

Hi,

Or , if I know which which wires were on which terminals on the old stat. I can tell you where to land them on the new one.

Thanks

Mark

Reply

WIRES ARE AS FALLOWS
        WIRE      TERMINAL
                 JUMPER TO R
          R           R
          O           O/B
          Y           Y
          G           G
          B           C
                      L
          X           E
          W           AUX

Answer

Reply

I went so far as to replace the old themostat it does the same thing I hear a humming noise or buzzing coming frome the blower unit

Answer

Hi,

The humming is probably the transformer overloading due to a direct short. Don't leave ti go like that or we will need a transformer. if we don't already do.

At the stat disconnect the wire on C and see if you still get that hum. Let me know,

Thanks

Mark

Reply

still hums with the wire on or off

Answer

Reply

tried that it still hums

Answer

Hi,

OK , it sounds like you need a transformer.

Thanks

Mark.

Reply

what do you think that will run or how hard a task isthat?

Answer

Hi,

A transformer is about 50 dollars and it isn't very hard to change if you get the matching one. If you get from a Trane dealer they should be able to get you the exact replacement. If you have a service call done it will probably run you around 150.00 to have it repaired.

Thanks

Mark.

Reply

thanks for your time you were very helpful

HVAC

Have your own HVAC question?

Related Hvac Topics:

Question

I have a trane xl 1200 high heat pump I changed the themostat with a honey well rth 7500, all wires attached per the heat pump wiring instructions except for the brown wire from the old "T" terminal. nothing comes on. what should I do?

Accepted Answer

Info Request

Hi, Or , if I know which which wires were on which terminals on the old stat. I can tell you where to land them on the new one. Thanks Mark

Reply

WIRES ARE AS FALLOWS WIRE TERMINAL JUMPER TO R R R O O/B Y Y G G B C L X E W AUX

Answer

Reply

I went so far as to replace the old themostat it does the same thing I hear a humming noise or buzzing coming frome the blower unit

Answer

Hi, The humming is probably the transformer overloading due to a direct short. Don't leave ti go like that or we will need a transformer. if we don't already do. At the stat disconnect the wire on C and see if you still get that hum. Let me know, Thanks Mark

Reply

still hums with the wire on or off

Answer

Reply

tried that it still hums

Answer

Hi, OK , it sounds like you need a transformer. Thanks Mark.

Reply

what do you think that will run or how hard a task isthat?

Answer

Hi, A transformer is about 50 dollars and it isn't very hard to change if you get the matching one. If you get from a Trane dealer they should be able to get you the exact replacement. If you have a service call done it will probably run you around 150.00 to have it repaired. Thanks Mark.

Reply

thanks for your time you were very helpful

Related HVAC Questions

Hi,

Or , if I know which which wires were on which terminals on the old stat. I can tell you where to land them on the new one.

Thanks

Mark

WIRES ARE AS FALLOWS
WIRE TERMINAL
JUMPER TO R
R R
O O/B
Y Y
G G
B C
L
X E
W AUX

Hi,

The humming is probably the transformer overloading due to a direct short. Don't leave ti go like that or we will need a transformer. if we don't already do.

At the stat disconnect the wire on C and see if you still get that hum. Let me know,

Thanks

Mark

Hi,

OK , it sounds like you need a transformer.

Thanks

Mark.

Hi,

A transformer is about 50 dollars and it isn't very hard to change if you get the matching one. If you get from a Trane dealer they should be able to get you the exact replacement. If you have a service call done it will probably run you around 150.00 to have it repaired.

Thanks

Mark.