Water drains into air return & onto floor

Yes thats how it works If you think the flow is too fast turn down the flow , with the valve on the water line .

not understanding how it works will get you that assumption
the full bottle will slowly empty when the water level in which it sits gets low enough for the atmospheric pressure to displace the water and let in an air bubble
That way there is always water for the unit to work
Same principle as the bottled water drink coolers in the office
putting a hole in the bottle and you will have water all over the floor
you need to check the humidity level of the air because if it is too high then the system will not work and so the bottles will not empty--really simple principle

Is the drain line clear?

This is typical especially if there is not much air flow across the humidifier. Make sure the fan is running in the humidiifier and the core does not need to be replaced. Sometimes I have had to turn the water valve back a little to cause less water to go through to conserve that wasted water.

YOUR HUMI IS IN NEED OF MAINTAINACE. THE CALCIUM DEPOSITS ARE CLOGGING THE THE SPONGE ROLLER THAT WOULD NORMALLY ABSORB THAT WATER, YOU ALSO HAVE THE HUMDITY SETTING RATHER HIGH THATS WHY THERES SO MUCH WATER. THE TUBE THAT IS LEAKING IS MADE TO DRAIN OFF EXCESS WATER FROM THE ROLLER AND THE REASON IT LEAKS IS BECAUSE IT ALSO NEEDS SERVICE JUST PULL IT OFF AND CUT THE SEWELLED PART OFF WITH RAZOR OR CUTTING KNIFE IF IT IS PLASTIC TUBING AND REPLACE IT. IT SHOULD BE DRAINING INTO THE DRAIN ON THE FLOOR WHERE THE FURNACE CONDENSATE TUBE IS.

hi the water runs down the pad the fan blows air across is , this controled by the stat which should control the water flow / on or off, this should be under warranty in the first year

Check the drain lines to make sure the are not plugged and check the hidifier pad to be sure it is not scaled up and not letting the water flow through the pad. Last thing is make sure the humidifier is level so the water isn't leaking out the cover instead of the drain.

Neither, even if the solenoid or humidistat stick, it should always drain properly. Is the unit mounted on the cold air return duct or the supply plenum? If it's mounted on the supply plenum, the water panel might be getting blown forward and spilling the water. High efficient furnaces also can leak water on the floor if its drain is restricted. If hum. is mounted on return duct make sure drain is clear by blowing through it. On Honeywell hum's I've seen the rubber hose from the solenoid valve to the distributor tray leak too, check the rubber 1/4" hose.

sounds like to me you have a condensation pump attached to your hvac system. this can be used to pump water produced during the cooling of your house when in the a/c mode. if you have a typical bypass humidifier, you will have excess water running past the water panel and it must be sent to a drain of some kind. I would imagine the pump is being used to get your bypass water to the drain. another scenario may be that you have a 90% condensing furnace. if your exhaust pipe for the furnace is made out of pcv pipe, it is a condensing gas furnace. it will produce water when it is running. the water if from the combustion gases being condensed in the secondary heat exchanger. this is normal. some condensing gas furnaces will draw combustion air from inside the house and some will have a second pvc pipe that is used to pulll combustion air from the outside of the house. either way, it is not dehumidifying your house. the humidifier should be able to keep up if it is runnng properly. you should have water running out the bottom drain of the humidifier any time the fan on your furnace is running and the humidistat is calling for humidity. if this is not happening, it is not wired properly.

If the unit was installed with a saddle valve, which is most often the case, you could try turning down the water pressure by tightening the valve a bit. Just follow the copper water line from the humidifier back to the main water line and look for a little valve that you can turn. Try to tighten this enough so that you still have water flowing, but at the proper volume so that it doesn't overflow and splash all over.