Reverse Polarity Faults

fanIs that new furnace you installed shutting down on reversed polarity? Did you check, double check, and recheck the ‘hot’ and ‘neutral’ lines but still can’t solve the mystery?
Here’s a tip: Take a look at what other appliances are sharing that power circuit.

Sometimes loads, like appliances, can back feed power to the homes neutral.
The back feed voltage causes the furnace control board to ‘see’ power on the neutral, giving a reversed polarity fault code.
True story; I once ran into this issue and the offending appliance was an old 1940’s vintage desk fan. We unplugged the fan, and the problem went away.

Patrick is Zen HVAC’s diagnostic and training guy. Patrick started in the trade the day he left technical school and never looked back. He's served in various technical and training roles in the HVAC industry but specializes in system troubleshooting and diagnostics, retro commissioning, and technical training. His moto: If I can understand it, anybody can. Patrick uses the Zen common sense approach to teach Patrick’s Likes- His Wife, kids and dog. Old pickup trucks. Hiking. The industrial Revolution. Patrick’s Dislikes- Taking work too seriously. Anything unintuitive. Emoticons :( Patrick’s Favorite famous person- Theodore Roosevelt “I am only an average man, But I work harder at it than the average man" Famous Patrick Quote- “Well, that was stupid of me”

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