York IDH072B21S Series Installation And Maintenance Manual page 2

Each model number and all matching model numbers within a system must have
the same version of software.
Follow these steps to verify that your product model numbers have the same
version of software.
• Access the main printed circuit board in each product.
• Locate a white sticker with a P-XXXX number or
• Connect a service checker and locate the ROM number.
For further assistance, please contact our Technical Support Center at 1 (844)
873-4445 and select Option 2.
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