Unit stopped working and discovered the circuit board missing

My crane cool mist stopped misting. I always use filter water. Cleaned it with vinegar. What's can I do?

It sounds like it is just miswired. The low voltage wiring off the humidistat should be on W and C on the circ. board at the furnace. If you have it on R and C then it will power it constantly regardless if the heat is running or not. W is only energized on a call for heat which is typically when you want that type of humidifier to run

Check for voltaged at the solenoid valve. This will either be a 24 volt or 110 volt solenoid valve. Confirm power into the unit 110 volts. If you have power into the unit and no voltaged at the solenoid valve on a call for humidification at the humidistat than the circuit board or the step down transfgormer has failed.. If you do have voltage at the solenid valve than the valve has failed.

Are you using a current sensing relay with this humidifier or a sail switch?

Here you go!!http://www.aprilaireparts.com/4238-circuit-board.html
I hope it works, Luis

I called the service company that put in my new furnace (FAmily Heating and Cooling in Detroit, very highly recommend these people)

Anyway they sent out a second service tech who determined that I would be better off having the humidifier wired to go on whenever the furnace fan was running instead of using the humidifier signal from the circuit board on the furnace. After he changed the wiring the unit runs fine. It is pretty likely that the circuit board was bad also.

J-

I had this problem several years ago. In order for the water to flow, the outside temperature sending unit must indicate to the controller that it is less than 60F. If not, the unit will not operate outside of test mode. Check the temp outside where your sending unit is (could the sun be heating that side of the house?) and ensure that the circuit to the sending unit is working. I had a bad wire splice inside a wire nut stopping the circuit. Took me a long while to figure it out.

If the outside temp and your sending unit circuit is ok, I wish you luck on your troubleshooting.

adx_98

I think I found the problem.

unplug humidifer, remove top tank, empty all water out of base. dry off.

turn unit upside down.

unscrew five visible screws.

use a screw driver to pull off the black foam foot pads. you will find more screws there.

pull off the base.

look next to the fan, you will see a metal "tower" going up into the reservoir. Is it dirty such as white chalky substance on it? Clean it with cotton swabs. Clean the fan while your at it if needed.

You will see a small gray box with two metal tabs twisted. Untwist them and pull off the top.

On that metal "tower" you will see a small black chip connected to the circuit board where you just removed the metal top. Does black chip have black marks on the circuit board? Mine does. I suspect the "tower" which draws heat from this black chip was no longer able to cool because of the white chalk buildup on the tower, furthermore, the chip became too hot and caused the black chip to overheat (again black marks on the circuit board).

The chip has on it "FTR 02N" and a "54F" at the bottom. I tried doing some basic searching on internet to see if it could be replaced, but didn't find anything.


For those who don't have this problem yet, just keep that metal cooling tower clean.

I also had the transformer problem and it was made worse but an HVAC guy who rewired the furance fan to get more air flow when he installed a new AC unit. He left the humidifier wired to the old fan windings which were now putting out 160 induced volts. The humidifier transformer, which was already undersized by Honeywell, never had a chance. Not sure how common this problem is but I later saw several references to the same problem on other websites and it's worth a quick check of the supply voltage to your humidifier.

Since I had an expensive humidifier and a whole cut in the furnace duct, I looked for a fix. My solution was to buy a $15 transformer from a BigBox that matched the voltage and was oversize on amps and mounted it externally to the humdifier (much like a furnace transformer is typically mounted). I then completely removed the piece-of-junk humidifier circuit board and wired the transformer directly to the water solenoid which it controlled and wired the fan and new transformer directly to 120V that is controlled by a current sensing relay (Aprilaire A50) on the furnace fan wires (and also controlled by a humidistat located on return air plenum).

It has worked fine for two years now, runs only when the fan is on and when the humidistat is asking for more humidity. A relatively cheap fix that would have only taken an hour if I had done it right from the start.
For those of you who haven't bought the Honeywell 360A yet - don't. For those of you like me that spent the money and cut holes in your duct - this is one solution.

Maybe Honeywell will wise up and redesign their transformer PCB to be much more robust. The rest of the unit is a pretty good design.