Hi we have a honeywell humidifier connected to our furnace we now here a buzzing sound what can this be from?

Not sure if you are still having your buzzing problem but I just fixed mine.. If you take off the front cover/fan assembly and remove the four torx screws holding the fan you can access the circuit board. There are two more small torx/flathead screws holding the transformer and board to the cover. Mine were loose causing the buzzing.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/justin_3ae27a9d61d6acd4

Hello. the buzzing sound you are hearing is coming from the solenoid valve on your humidifier. This could be due to low water flow going into the solenoid or the valve itself is going bad. I would check the saddle valve first and make sure you are getting a good stream of water to the solenoid valve, sometimes sediment gets built up in the saddle valve preventing water to flow. If the water flow looks good then replace solenoid valve.