Water leaking / running from top of humidifier

The humidifier should run in winter, however if the windows are fogged up it means the humidistat is set too high. Try lowerimg the setting on tue humidistat.

Hope this helps, check and see if humidistat is set to 35% humidity and that bypass damper on humidifier is in the open position or winter position.(humidistat is usually located on cold air return duct near furnace). Next, replace humidifier media pad, remember to replace media pad (filter) annually, you also may want to clean any lime deposit out of humidifier housing with a solution of warm water and white vinegar before installing your new media filter.Remember to turn power off at side of furnace when cleaning humidifier and replacing media. Before installing new media turn power back on to furnace, set humidistat to the on position, turn furnace thermostat above room temp., and inspect humidifier to see if water is running from top,(you may want to have a bucket under humidifier when checking for water), if you see water running, turn power back off to furnace, properly install new media filter, reconnect humidifier cover & set humidistat to 35%. If you do not see water present, check water supply valve to humidifier and make sure its turned on. If water supply valve is open, then check water supply tubing for blockage.And the last things to check is to make sure all registers through out your home are open and not blocked by any objects, also make sure furnace filter is cleaned, if none of this works refer to installation manual to see if humidifier was sized and installed properly, Good luck.

If there is water and power to humidifier you need a new solenoid valve or humidistat.

If the water stops when the heater is not running then the humidifier is working fine. I know it seems like alot of water but that's how it's designed.

Hi check power at transformer / valve on water line could be stuck open clean valve out or transformer holding valve open

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.

The furnace should be equipped with a #50 relay to turn the Humidifier on and off when only when the furnace blower is on. You should have a test mode on your humidistat. Do you have water coming up to the solenoid valve? Make sure that the saddle valve is turned on to supply the water to the humidifier. Is your humidistat set high enough to turn the humidifier on? Is it plugged in?
Good luch
HVAC Teacher

No water should not just sit there in the system. It is supposed to recirculate itself. You should really call a tech out and have them check your system.

This may not be a solution, but a couple things you might want to look at. First, the humidifier may not be big enough for your house - just because a contractor installed it doesn't mean he sized it right. Second, humidity may only be 30% locally by the humidistat, but higher in other parts of the house - it depends where the humidistat is located. Finally, look at your hot water line - I'm surprised he ran it off hot water and not cold - seems like a waste of energy to me, but the feed line may be clogged by sediment from the water heater

You can try installing the water line to your hot water if it is installed on cold line for more humidification. You should make sure your humidistat is up line 6" @least from humidifier for proper humidification measurement.