The control for the air cleaner is saying it is filtering even when it is disconnected from the unit and also when the unit is not actually filtering.
Thank you for contacting us with regards to your model 5000 Electronic Air Cleaner. The air cleaner control works on a negative signal logic, meaning that when it sees no connection to the furnace or thermostat, it assumes the fan is running and the air cleaner is working. The control needs to be wired in properly in order to truly see when the fan is active or not. If it still shows Filtering when the control is connected, there may be a problem with the wiring. We would recommend that you contact your installer to troubleshoot the installation further.
We appreciate the opportunity to be of assistance.