On this page, you will find more information about the most common causes and most relevant solutions for the AC error 'dn'. Do you need help straight away? Visit our support page.
The Lennox documentation indicates that error code 'dn' is caused by the following problem: "Communication line misconnected or expansion valve error".
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We've created a list of solutions which you can follow if you want to solve this AC problem yourself. Do you need more help? Visit our support page if you need professional support with AC right away.