@Brad104 and @Loves2Trim and anyone else getting one of these temp controllers. The ‘magic’ lies in a hidden setting. It is the very last setting in your owners manual, under Advanced Settings. The ST setting is what you want to set before setting anything else. When you enter the ST mode, it will reset ALL other setting to default, so do this FIRST! BN-Link does not bother to mention how to access that ST setting. Shame on BN-Link! To access it, you have to press the set button and the CF/ST button at the same time. That will take you to the ST setting where you can change it from 10 to 01. Then you will also want to set your Hd and Cd values to 0 (zero). Make sure your CF setting is on F, set your SV for something that the PV can not hit, like 70.0, and get to playing with it. That should allow you to hold your set temp while the controller tried to hit a SV that doesn’t exist on the PV. back and forth and back and forth………heater, exaust, heater, exaust…… equals a steady temp with ventilation!
Here is that manual, for your refference, https://cdn.shopify.com/s/files/1/0018/2521/0421/files/BNQ-T10Wifi.pdf?v=95648123402206472