Aeration System - Curtis RU-150 Service Manual

AERATION SYSTEM

For the contact points referenced in this section,
see the schematic diagram below.
Components Involved:
1. Aeration Tubes.
2. Air Pump
3. Aeration Timer
4. Manual Aeration Switch
AUTOMATIC AERATION
PROBLEM: Only one of the liners is aerated.
TEST: Inside the control box, there are two sili-
cone tubes connecting the aeration pump to the ¼"
copper tubes coming from inside the urn. Carefully,
pull the silicone tubes from the copper tubes, press
the manual aeration button and feel for air flow
from the silicone tubes. Replace the pump if air
does not blow through the tubes.
Air Pump Tubes.
NOTE: When replacing the silicone
tubing on the copper tubes, make
sure you do not cover the small
holes on the copper tubes.
These are air release
holes that pump into the
liner so coffee can refill
the gauge glass.
PROBLEM: Aeration system fails to operate
automatically.
TEST: Determine that the aeration pump is
operating by pressing the manual aeration button
on the front panel to see that air comes from the
tubes.
AGITATION TIMER
Check the agitation timer. Remove the Black wire
from point A, terminal 1 on the timer. Discon-
nect the Black wire from the areator switch (point
B). Plug this wire into the terminal 1 of the timer
(dashed line). The air pump should immediately
start pumping air into the liner. If this test fails,
replace the agitation timer WC-405R. If the pump
runs normally, then replace the wires to their
proper connections and proceed to test the aera-
tion switch, below.
MANUAL AERATION
PROBLEM: Manual aeration is not present on
either of the liners, yet automatic aeration oper-
ates normally.
TEST: Check the continuity of the manual aera-
tion switch. Power to the control circuit must be
turned off to check for continuity. Check at the
YELLOW wire at point C of the agitation timer
and B (BLACK wire) of the manual aeration
switch. Press the switch to look for continuity.
Check for clean, tight connections at all termi-
nals.
C
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