20 Most Recent Aprilaire 700 Humidifier - Page 9 Questions & Answers

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

sounds like either the motor is off balance
or is going bad again
either way id be on the phone to the guy who did the rapair
more than likely the set screw on the sqiral cage came loose and now its vibrating

Turn it to test with the furnace running and watch the drain.

Turn the humidistat all the way up. This is the test position that will cause it to run continuously. The blower or furnace must be running, depending on how it is wired. If the humidifier has never been serviced in five years, call a professional. The orifices will plug and pad deteriorates after about a year. These need yearly maintenance to operate correctly.

soliniod may be stuck. you will need a volt meter to test

the solinid may be stuck or the humistat is wired wrong

if it comes on when turned to RESET then its probably fine. The humidity may be higher than the highest setting on the stat. If you leave it on test reset it will not work .

you need to replace the pad every season. if you are using a generic pad maybe more often. it also must be level and the drain coming off bottom clear. i suggest getting pads from aprilaire.com . not the generic from hardware store. also if its got a black feed tube going from the solinoid valve to the top of the humidifier pad you may want to replace that aswell, they have been known to crack the new ones are grey.

i believe e3 is an outdoor sensor problem, most people use manual mode, you should see a blue jumper that is connected to 2 OD terminals at the control, or if u use a sensor there should be a wire run outdoors, if you dont have the manual mode part you have to get it from an aprilaire dealer, cant just jump it out, it is a resistor

A bad circuit board should not make any noises. A bad solenoid valve could make a loud buzzing noise. If the noise is a squealing noise then you have defective bearings in the blower motor.
If you disconnect the low voltage wiring from the solenoid valve and you still hear the noise, then its not the solenoid valve.

If the water continues runs nonstop even when the heater is turned off, you might have either a bad solenoid valve or a bad humidistat. Simply disconnect one of the two low voltage wires going into the unit. If the water turns off then your problem is most likely your humidistat or the low voltage wiring. If the water continues to run even when the low voltage is disconnected you have a defective solenoid valve.
Good luck.......

I'm assuming this unit has a reservoir installed in the heat duct and has a rotating pad in a wire cage -- is this correct?

If so, it sounds as if the float valve in the humidifier reservoir is out of adjustment or the valve is leaking, The reservoir is overfilling and running into the sump.

There is an adjustment on the float, if lowering the float does not solve the problem, the valve is leaking -- it'll probably need replacing.

When you replaced the solenoid valve did you clean the orifice? It is in the waterline by the solenoid valve It is a small plastic plug with a very small hole. Pull "one" wire out of a wire brush. This should be small enough to poke though to open the orifice.
Good luck

Hopefully it was installed properly. It should only allow water to run when the furnaces blower is on. The outdoor probe can only be properly checked with an ohm meter. When you replace the evaporative panel, it is very important to have the dark painted mark on the "top" of the panel when it is installed. They do not give these instructions to a homeowner, only a contractor. So i am betting that your new water panel is installed upside down.
Good luck

Clean the air filter to avoid the humidity.....

Does your humidistat have any dip switches or a small jumper wire? if it does try switching positions of the jumper or change dip switch. hope this helps

Sure. But if your homemade gasket leaks try a little 100% silicone caulking. It smells bad for an hour or so but it will help. If you use the silicon make sure you allow it to thoroughly dry before you get it wet or it "will" leak.
Good luck
HVAC Teacher

There is a small oriface that is installed next to the solenoid valve. It sounds like this oriface is missing. It reduces the water flow through the humidifier when it is working properly. You should be able to disassemble the solenoid fittings to check and see if the oriface is in the water line. For a "temporary" fix regulate the water pressure down by closing down on the saddle valve.
Good luck
HVAC Teacher

Check your plastic water orifice. It is in the hose fitting connected to the outlet tube of the water solenoid. It should be a blue one. Mine was completely eaten through, allowing full water flow, and thus overflowing the distribution tray. I replaced mine yesterday and no more water drips. May as well reflace the filter on the inlet tube of the solenoid at the same time. I used a piece of very stiff, but thin, wire formed into a small hook to remove both old parts. Replacements are readily available from multiple sources on line.

Could use a little more info, but check this

These guys like to sit level and have all the parts in correctly. Double check that its is mounted level. When you change a filter on them the has to go in the exact way it came out and the plates with the tube have to line up just so. The filter has to also sit level so the water can trickle in the holes on top properly. That top bracket has to be sitting on the filter properly. Hope that helps