Aprilaire 350 Owner's Manual page 8

ForModels400A,400M, 500A,500M, 600Aand 600Mclosethe bypass
damper, w hich is a partof the humidifier,with the small damperhandle.
HumidifierControl:
AutomaticDigital HumidifierControlin AutomaticMode(seeFigure A):
Noadjustmentis necessary.
AutomaticDigital HumidifierControlin ManualMode(seeFigure B):
Setthe knobto the "OFF"position.
ManualHumidifierControl ( seeFigure C):Setthe knobto the "OFF"
position.
NOTE:Periodicinspection and preventative maintenanceof your total
heatingsystemis importantfor efficient and safe operation.Your heating
contractorcan serviceyour humidifier at the same time he servicesthe
HVACsystem.
All models havea distributiontray abovethe Water Panel,which shouldbe
inspectedannuallyand cleanedof excessmineraldeposits.Oldermodels
havea granularcoatingin the distributiontray. Do not scrapethe granuals
out of the tray. Newermodelshavea fabric liner in the distributiontray.
[]_ WATER
FEEDTUBE
OUTLET
COMPRESSION
NUT
ORIFICE
_ OLENOID
VALVE
INLET
90 1053
IN-LINE
STRAINER
'C O%RESS,ON
NUT
1. Disconnect e lectricalpower to the HVAC
andshut off water supply.
2. Disconnectthe water line at the inlet
compression nut.
3. Removethe in-line strainer from inside
the inlet sideof the valvebyusinga small
nail or wire.
4. Flushthe in-line strainerclean or replace
with a new strainer,PartNo. 4004.
5. Reconnectthe inlet water line. Double
Wrench to PreventLeaking.
6. Disconnectthe water feed tube at the
outlet compression nut.
7. Inspect the water feed tube by gently
flexing it andlookingfor cracksor signsof
wear. Replacetubeif it is cracked,brittle,
or has beendamaged.
8. Inspectthe orifice in the water feed tube
and make sure the small opening is
unplugged.
9. Reconnectthe water feed tube. Double Wrench to Prevent Leaking.
10. Remove the drainlinefrom the bottomof the humidifier.If applicable, f lex it
to loosenanymineraldepositsor blockages. Flushthe drainlinewith water
underpressure to clearit of anydebris,andslip it backontothe drainfitting.
If drainlinedoesnot flow properly,replaceit. Inspect t he drainlineto make
sure it has a constantdownwardslope and is not flattened or blocked.
11. Turn on water supply and reconnect electrical power to the HVAC.
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