Annual Summer Shutdown; Periodic Preventative Maintenance - Aprilaire 350 Safety & Operating Instructions Manual

ANNUAL SUMMER SHUTDOWN

For Models 400, 400M, 500, 500M, 600 and 600M close the bypass
damper, which is a part of the humidifier, with the small damper handle.
Humidifier Control:
Digital Humidifier Control in Automatic Mode (see Figure A):
No adjustment is necessary.
Digital Humidifier Control in Manual Mode (see Figure B):
Set the knob to the "OFF" position.
Manual Humidifier Control (see Figure C): Set the knob to the
"OFF" position.
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PERIODIC PREVENTATIVE MAINTENANCE

NOTE: Periodic inspection and preventative maintenance of your total
heating system is important for efficient and safe operation. Your heating
contractor can service your humidifier when he services the HVAC system.
All models have a distribution tray above the Water Panel, which should be
inspected annually and cleaned of excess mineral deposits.
WATER LINE INSPECTION AND SERVICE INSTRUCTIONS
WATER
FEED TUBE
OUTLET
COMPRESSION
NUT
ORIFICE
SOLENOID
VALVE
INLET
IN-LINE
STRAINER
INLET
COMPRESSION
NUT
90-1053
9. Reconnect the water feed tube. Double Wrench to Prevent Leaking.
10. Remove the drain line from the bottom of the humidifier. If applicable, flex it
to loosen any mineral deposits or blockages. Flush the drain line with water
under pressure to clear it of any debris, and slip it back onto the drain fitting.
If drain line does not flow properly, replace it. Inspect the drain line to make
sure it has a constant downward slope and is not flattened or blocked.
11. Turn on water supply and reconnect electrical power to the HVAC.
1. Disconnect electrical power to the HVAC
and shut off water supply.
2. Disconnect the water line at the inlet
compression nut.
3. Remove the in-line strainer from inside
the inlet side of the valve by using a small
nail or wire.
4. Flush the in-line strainer clean or replace
with a new strainer, Part No. 4004.
5. Reconnect the inlet water line. Double
Wrench to Prevent Leaking.
6. Disconnect the water feed tube at the
outlet compression nut.
7. Inspect the water feed tube by gently
flexing it and looking for cracks or signs
of wear. Replace tube if it is cracked,
brittle, or has been damaged.
8. Inspect the orifice in the water feed
tube and make sure the small opening is
unplugged.
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