Terminal 64 should read 0V and terminal 66 should have a positive voltage. Please click here to view the manual (https://www.reznor.co.uk/wp-content/uploads/2025/09/Reznor-OP314.4-GM44-Installation-Instructions-EN-2010-04-1004031444-EN.pdf) for more information.
How does the GM44 modulating PCB work with a 0-10V DC signal?
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