My 821 000 LCD Display does not show up. There is black down in the left hand corner. Can this be fixed?

That unit is specialized and proprietary and you will not find any information to service it yourself. Since it is licensed and considered medically regulated, you must return it to the manufacturer for repair

no info generic answer ---check fan and compressor

I fixed my machine with this error by doing the following.
You need a T8 torx screwdriver and a thin flat blade srewdriver plus a replacement CR2032 button cell. Ensure that the S9 is disconnected from its power adapter. First pry up on the setting rotary knob at the top of the S9 and remove. Next remove the T8 torx screw from the bottom corner of the machine. There are then four slots located on two of the sides. Insert the flat blade screwdriver into one of the slots and gently push inward to unlatch that finger while also lifting/prying up the bottom cover. You should then be able to work your way around to each of the fingers and lift the bottom cover off. This then exposes the circuit board. There are two more T8 torx screws holding the circuit board in place. Remove them and carefully lift the board slightly. You can then see the button cell in it's holder at the corner which can now be removed and replaced with the new CR2032. The S9 can now be reassembled in the reverse order. Once reassembled, connect the power adapter but do not power on yet or you'll get the same error message as before. Hold down the power button and then while still holding it down power up the machine. Good luck, hope this helps.

Clean pilot , replace thermo couple if it looks burnt out clean flame sensor

Thank you for contacting us. Does your humidistat have a blower activation switch on the lower left hand side of the humidistat? If you do it is our #60 humidistat, and if it is not there you have a #58 humidistat. The R & C are the two connections that supply power to the humidistat to give you the numbers on the digital display. The 60 you wire right into the R & C off the furnace panel. The 58 you need a constant 24 volt and 10 VA power source which you could get by using the transformer off a constant 120 volt power source to power the humidstat. If you are doing this correctly and you still do not get the numbers to show up, then you have a bad humidistat and you need to go back to where you purchased it from and exchange it under warranty provided you used a certified HVAC contractor to do the installation. Our warranty is only valid if you used a certified HVAC contractor to do the installation. If you have any additional questions please contact us at 800-334-6011.

Thank you

www.aprilaire.com

Kevin Engen
Customer Service
Research Products Corporation

the switch is bad or there is a loose wire connection, if you have a multi-meter you can check the resistance on the switch, it should be 0.0-0.2 if the switch is good it could be the pump.If the pump is bad don't bother fixing it.

It would appear to me that you have lost the 24 volt power supply to the thermostat. In referencing the manuals for this thermostat, available @ www.honeywell.com, I've found that when the thermostat is not connected to the wall plate (plate mounted on the wall, that the thermostat either snaps or screws into), it will display the -AC. This being said, either the thermostat is loose on the wall currently, or your 24 volt transformer has died. Hope this helps.

What you can do is try and clean the contacts. Open the door on the thermistat and remove the two screws, after that you can seperate the part that is mounted to the wall and the front panel. Look at the part that is mounted on the wall and you'll see the contacts that should be a copper color. They might be black from age. Clean them and you'll be surprised how well it will work after that.

Denis

possible damage to LCD
it is a liquid display and wiping the screen may have damaged the display --same as pressing on a LCD tv screen with the finger will distort the display at the finger point

I've been having problems with this unit since purchase in December 2007.

To fill, unscrew the cap with the spring loaded plunger. It may be tight, but it has two slots which you can turn like a screwhead using something wide enough (eg, a spoon) for leverage.

My problem is that this thing leaks badly. The fit of the cartridge is terribly designed. The one supplied is different from the one depicted in the unhelpful manual, which is silent on where the cartridge should fit. It will fit in one spot, but it will not sit flush with floor of the unit; it rocks and the water holding top rocks with it. The supplied cartridge appears to be an attempted and unsuccessful fix of a problematic design.

Even without the cartridge, this unit still leaks.

A web search shows others complaining about leaking. Hate to say it, but another example of lousy American design... but it sure is pretty!

Haven't been able to raise the manufacturer "Kaz" on the phone.

Good luck!