20 Most Recent Aprilaire 600 Humidifier - Page 6 Questions & Answers

first make sure you have water going to it. you can shut off the supply disconnect from solinoid then turn on and see if water is coming out. If so if you have a very small flat head screw driver you can try to remove the pre screen inside the inlet of the soliniod. clean it and reinstall. reconnect the water line and energize the valve if you still have no water then either the valve is bad or your not getting voltage to the valve, if its a voltage problem it can get complicated and you would need the tools and some electrical knowledge to follow me.

If I'm not mistaken, the 600 has a automatic or manual control built in to the same humidistat. The only thing required is the outside air sensor (oas) be mounted outside and wired into the humidistat. Don't forget to remove the "manual" jumper from the humidistat.

the on setting is actually a test setting. the humidistat with the aprilaire does not have an on setting you can only set it just below test which would be it's highest setting

go for the Aprilaire 600 but make sure they install the outdoor sensor and set it up for AUTO operation

if the wire to the outdoor sensor runs close to high voltage wiring it may cause that

lift the frontup2 inches should drain out back if not blocked
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replace the AA#35 water panel annually also try poring a touch of bleach where the pump is the pads have the coating to keep them from rusting you miht be able to find a generic paper model if you look at your local department store

If the installer used a #50 relay when they installed it they did not take in consideration the the fan will run at two different speeds in heating. Remove the #50 relay from the blower wire it is connected to. Reinstall it on the blowers white wire (neutral). This should fix the problem.
Good luck

I assume the temp dial you are referring to is the humidistat. If it only works when you apply manual pressure. You have bad contactsin the humidistat. Replace the stat.
Good luck
HVAC Teacher

There is a devise called a current sensing relay (a little black box that hangs on a blower motor wire that senses current from that wire) If you have such a devise it should hang from the white (common) wire. Loop the wire through twice.

The coil may shorting out the 24vac supply to the solenoid. Recommend replacing soleniod.
Normally you should be able to read the 24vac across the solenoid when energized.
The other option is to get a 120vac to 24vac transformer and test the solenoid. This way you will know if the solenoid is the cause or the 24vac source is the problem.

Clean it and dry it thoughly. Apply a small amount of 100 % silcone caulking with you finger. Seal it on both sides. Allow it to dry thoughly before it gets wet or it will leak.

The oriface is sized for the proper water flow for the model you purchased. If you are dissatisfied you could throttle down on the saddle valve to restrict the water flow to the unit.
Good luck
HVAC Teacher

Yes, just check to see if you have 24 volts going into the solenoid. If you do and it is not opening its probably bad. Since you verified the water lines, filter, orifice and saddle valves are not obstructed. Change the solenoid valve. When you price the part. (it's not cheap) consider paying about 30% more and just change the whole unit.
Good luk
HVAC Teacher

Commonly outdoor wood boilers use a hot water coil mounted in the ductwork above your furnace. In this application the Ruud furnace is still using its blower assembly to circulate the warm air from the boiler to your home. If this is the case. Have your heating guy install a #50 relay on the furnaces blower motor to activate your much needed humidifier. If this is not the case and your Ruud furnace is totally independent of the boiler. Still install the #50 relay in the furnace and manualy activate the fan only feature on your thermostat.
Good luck
HVAC Teacher

the change water panel light is just a timer. it does not sense that the water panel actually needs to be replaced. sounds like you have a solenoid issue. if you have water to the solenoid and are certain you are getting 24v to it, the solenoid is ethier bad or plugged with calcium. most likely calcium. sometimes you can take them apart and clean them. so, it you can hear clicking at the solenoid when you turn the humidstat up and down. try cleaning it.

HVAC Mechanic.com

The max the aprilaire can put out is 45% Rh. Your humidifier may wired up to run only when the heat is on. In some cases this is not enough time to maintain your humidity level your seeking. To correct this, the hum. has to hooked up the hot side of the water supply. And the humidifier has to be hooked up when the fan runs and leave the fan run constantly

I corrected the problem...RH is rising nicely!! Installed by "professionals" on my Trane XV90....I redid their wiring and now have the following setup...

600A water supply coming from hot water line.
Removed orifice inside incoming feed tube.
control incoming water flow from saddlevalve on hot water supply ( make sure its a nice solid flow, no drips, but no "force" too it either)..enough to insure entire evaporator unit is wet and water is slightly flowing out of bottom to drain.

I also have it wired to run when ever the furnace blower is on. Heat or no heat. XV90 is variable speed, and by doing this the 600a is always adding moisture, until it reaches correct RH%

Also, I disconnected the outdoor temp sensor. I went to Radio Shack and bought a 47K ohm resistor ( 1/2 watt....4 pack for 99 cents). Installed that in place of outdoor sensor...now runs in manual mode. Have unit currently set to number 5.