Aprilaire 1150 Installation, Operation And Maintenance Manual page 36

D . If the steam chamber is cool to the touch, skip to Step 1E . If the chamber is hot, the water must be cooled down before
draining and handling of the chamber . This can be accomplished by allowing sufficient time for the chamber to become cool
enough to handle . As an alternative, if the drain piping is designed to handle intermittent drain water temperatures up to
212°F (100°C), the chamber may be cooled down by moving the lever located on the drain valve actuator to the manual open
position . The fill valve eventually opens, allowing water to run into the chamber until it is cool enough to handle .
IMPORTANT: If water is not draining from the chamber after Step 1D, the drain valve is likely clogged and the chamber
must be cooled by introducing overfill water into the chamber . To do this, unplug the probe plug from the probe assembly
(located on the chamber cover) to allow the fill valve to energize and overfill the chamber . When the chamber is cool enough
to handle, plug the probe plug back into the probe assembly . Take necessary precautions to support the additional
water weight when removing the steam chamber fasteners.
wARNINg
Opening the drain valve when the steam chamber is hot may discharge water with a temperature up to 212°F
(100°C) into the plumbing system . This may cause damage to the plumbing system . Do not touch the chamber or drain piping
until the chamber has had sufficient time to cool or serious injury may result .
E . Shut off the water supply .
F . Shut off the electrical supply .
G . Allow the steam chamber to completely drain .
H . Disconnect the drain hose or field-installed union from the drain valve connection on the back left corner of the cabinet .
Disconnect the drain valve electrical plug .
2 . Remove the steam chamber (see figure 29 for drawing item numbers):
• H old up on the bottom of the steam chamber (Item 6 in drawing) and remove the top mounting nuts (Items 2 and 3).
• H old up on the bottom of the steam chamber while removing the bottom mounting nut (Item 4). When the bottom mounting
nut is removed, the handle (Item 5) falls away from the steam chamber . Use both hands to support the steam chamber and
lower it straight down to clear heaters . Use care not to damage gasket which is attached to the top lip of the chamber .
3 . Clean the steam chamber interior by rinsing with clean water . Use a putty knife or similar flat instrument to remove mineral
deposits . Clean the strainer inside the steam chamber located over the steam chamber drain opening . Use a wire brush and
verify that all the strainer holes are open .
4 . Open the drain valve with the manual lever on the side of the actuator (Item 11) and run water through the drain valve to
remove any collected sediment .
5 . Unscrew the probe assembly and clean the plastic probe housing, ensuring that
all passageways are clear (see figure 30) . Clean the probe rods using steel
wool or a similar mild abrasive material . Inspect the composite plastic probe
assembly for any signs of cracking, roughness, or deterioration . Replace if
necessary with Part Number 4580 .
6 . Install the probe assembly, probe plug, probe housing and the gasket into the
cover (see figure 30) .
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fIgURE 30 – Probe Rod Assembly
Probe housing
Probe
plug
Probe
assembly
OM-4052