I have a carrier furnace, humidifier valve popped fuse

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

Your humidifier is a bypass type. The only voltage needed is 24vac to open the water valve. Air only flows through the humidifier when the furnace blower is running, and the wet pad will add very little humidity if the furnace is not running and heating the air before flowing through the wet pad in the humidifier.
It is best the water valve is only energized when the furnace is running. Some furnaces have a connector on their control boards labeled HUM for this purpose. Test it's voltage when the furnace is running because some will output 110vac instead of 24vac you need.

Hello, The humidifier should turn on and off with the furnace's blower motor, If the humidifier keeps continously running than the solenoid valve is stuck open and should be replaced.

Make sure damper dial on humidifier if open, winter. Also most humidifiers recommend to supply unit with hot water instead of cold (evaporates faster).

Do you feel like looking at the humidifier yourself?
You can open the door on the unit, while the furnace is running--
The humidifier is usually installed in the return air duct, so there will be a sucking of air into the open door, when you open it.

There is usually a large wheel, with a wet pad wrapped around the circumference.
This wheel rotates slowly, and picks up water from the sump-- does everything look and sound quiet as it runs? -- The float valve has to open and close, to c ontrol the leve of water in the sump-- (The pool of water the wheel runs the mat thru--
Possibly the valve shutting off, could make a plumbing BANG-- you could duplicate that, by lifting the float mechanism and stopping the water-- does that make the noise?

If you can reach and operate the Humidistat control from near the humidifier, do so a few time-- or Have someone cycle the humidistat a few times, and you listen for that sound--
Is it in the humidifier itself, or the duct work nearby?

It might be that the humidistat wheel scrapes against the side of the sheet metal duct work? -- Sounds travel a long ways in metal duct work!

Let us know if this helps

Mack B

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

This posted question is exactly one year old, but I just got this solenoid valve assy from ontimemall in Phoenix AZ. I don't have the receipt right here, but it was about $90. It is classified as: honeywell 32001639-002 solenoid valve.

flame rod sensor

sounds like you need a gas valve or inlet pressure adjustment. You will need a proper pressure guage for this.

I would suggest turning up the humidistat (usually located on the the return air duct to a higher setting and listening for a "click" noise on the supply valve. If you do hear a click but dont see / hear any water than the culprit is likely the valve itself.