Furnace Transformer

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Old 10-01-17, 12:42 PM
Gen
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Furnace Transformer

I have an old Carrie furnace circa 1997. The circuit board was recently replaced, and when I looked I noticed the wire on the transformer--not bad, but a little brittle. One of the primary wire insertion points into the trans looked like it was a little melted.

Do transformers generally go bad? If so, would it be worth it to replace it before it's 10 degrees outside?
 
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Old 10-01-17, 12:52 PM
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No...transformers don't usually go bad unless short circuited.
The wiring rarely shows any sign of aging. Cracking can occur if the wire is directly in a heat path.

Transformers are inexpensive and sold everywhere. Always good to have a spare around.
120vac -> 24vac at 40va.
 
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Old 10-01-17, 12:52 PM
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Do you have a multi meter to test the power? A visual inspection isn't enough.
 
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Old 10-01-17, 01:03 PM
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Do I have to replace with a trans that is generic/part number matched to the furnace? Or can I just get a 24v-40va unit and go from there?

I will consider checking the output, though at present everything--heat cool and fan works fine.

PS How do I enlarge the DIY forum font? I'm typing incredibly small characters.
 
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Old 10-01-17, 01:09 PM
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Your system is working...your transformer is working.
You can use ANY 120v-24v transformer.

If you have the box outlined in the diagram below.
Clicking on it will increase only the text edit size.
The up and down arrows change the box size.
 
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Old 10-02-17, 06:51 PM
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Trans measures a bit over 27 volts. Is that OK?
 
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Old 10-02-17, 06:54 PM
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Yes..... that is ok. There is probably minimal load on it.
It will come down some when loaded.
 
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