I have a Aprilaire 600m model and should I conect the water supply to the hot or cold line.
Thank you for your email regarding your model 600M Aprilaire humidifier. Your Aprilaire humidifier will operate on hot, cold hard or soft water. We do however recommend hot water as it will increase the evaporative capacity of the humidifier. Hot water will also allow you to operate your humidifier during a fan call. A heat source is required for the evaporation process. During a fan call the only source of heat is hot water.