Maintenance; Air Filter; Air Distribution Box Housing; Service-Unit Does Not Operate - Dometic 640312 Series Installation And Operating Instructions Manual

MAINTENANCE

A. Air Filter
1. Periodically (a minimum of every 2 weeks of op-
eration) slide out the return air filters located on
the end of the air distribution box. Wash the filters
with soap and warm water, let dry and then rein-
stall.
Note: To insure easy future removal the filters need to be
replaced with the domed side of their handle positioned
towards the ceiling.
Note: Never run the unit without both return air filters in
place. This will plug the unit evaporator coil with dirt and
may substantially degrade the performance of the unit
over time.
B. Air Distribution Box Housing
1. Clean air distribution box housing with a soft cloth
dampened with a mild detergent. Never use furni-
ture polish or scouring powders.
C. Fan Motor
1. The blower motor is factory lubricated and re-
quires no service.
D. Frost Formation On Cooling Coil
1. Frost on a small portion of the coil is not unusual.
Under certain conditions, ice may form on the
evaporator coil. This is indicated by very cold out-
put at very low air speed and the icing can be
seen through the hole network with the filters re-
moved. If this should occur, inspect the filter and
clean if dirty. Make sure air vents are open and
not obstructed. Units have a greater tendency to
frost when the outside temperature is relatively
low. This may be prevented by adjusting the ther-
mostat control knob to a warmer setting (counter
clockwise). Should frosting continue, operate on
any fan ONLY setting until the cooling coil is free
of frost; then resume normal operation. If frost
condition persist, contact your local service cen-
ter for assistance.

SERVICE-UNIT DOES NOT OPERATE

If your unit fails to operate or operates improperly, check
the following before calling your service center.
A. If RV connected to motor generator, check to be sure
motor generator is running and producing power.
B.
If RV connected to power supply by a land line, check
to be sure line is sized properly to run unit load and it
is plugged into power supply.
C. Check your fuse or circuit breaker to see if it is open.
Insure fuse is not burnt, or circuit breaker is "ON"
and not activated.
D. After the above checks, call your local service center
for further help. This unit must be serviced by quali-
fied service personnel only.
E. When calling for service, always give the following:
1. Unit model and serial number found on identification
label located on base pan of unit bottom. (Remove
filter and view through network of holes)
2. Air distribution box model and serial number found
on rating plate located on ceiling template. Observe
this rating plate through the air distribution box right
side vent opening.
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