Armstrong Air Tech 90+ Furnace 9 Flashes

Old 10-07-12, 04:25 AM
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Question Armstrong Air Tech 90+ Furnace 9 Flashes

I have never done anything to any wiring or any kind on the furnace or on anything else in my house before. I have never had any problems with it till now. The fuse has blown two mornings in a row. I replaced the fuse and it ran yesterday day fine, all day. Then I get up and the fuse was blown this morning. I finally pushed the flash history button and it flashed nine times indicating "incorrect line voltage phasing-reversed polarity." 3 times in a row. When I have the unit on, with a new fuse, heat switched off on the thermostat the red light indicates nothing. Now, when I turn the heat on it will start to run and then blows the fuse. Nothing I am reading about on similar situations seems exactly that same. This seems especially odd since I have never had any problems with its polarity if the wires needed to be simply switched. It should have trip way before this moment I would think.
Old 10-07-12, 07:15 AM
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are you speaking of the low voltage fuse on the control board or the high voltage fuse for 120V coming into the furnace? It is likely you have a ground issue (loose)? DO you have a volt meter and know how to use it? Likely your control board has failed.

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