Periodic Preventative Maintenance                                15 - Aprilaire 300 Owner's Manual

PERIODIC PREVENTATIVE MAINTENANCE
NOTE: Periodic inspection and preventative maintenance of your total
heating system is important for efficient and safe operation. Your
HVAC contractor can service your humidifier when they service your
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
1. Disconnect electrical power to the HVAC
system 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. Remove the orifice from the water feed
tube and make sure the small opening is
unplugged.
9. Replace the orifice with Part No. 4231 (yellow) or
4232 (blue), by model, if missing or damaged,
and reconnect the water feed tube. Double
wrench to prevent leaking
10. Remove the drain line from the bottom of the
humidifier. If necessary, flex it to loosen any
mineral deposits or blockages.
11. 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.
12. Inspect the drain line to make sure it has a
constant downward slope and is not flattened
or blocked.
13. Turn on water supply and reconnect electrical
power to the HVAC system.
A
B
C
D
E
F
G
90-1053
A. WATER FEED TUBE
B. OUTLET
COMPRESSION
NUT
C. ORIFICE
D. SOLENOID VALVE
E. INLET
F. INLINE STRAINER
G. INLET
COMPRESSION
NUT
15