Emergency Heat; Performing Routine Maintenance - Carrier 38YKC Series Manual To Operating & Maintenance

Do not be alarmed if steam or fog appears at the outdoor
unit during the defrost cycle. Water vapor from the melting
ice may condense into a mist in the cold outside air.
During certain weather conditions such as heavy snow and
freezing rain it is not uncommon for ice to build up on the
outdoor unit grille. This is normal for these weather condi-
tions. Do not attempt to remove the ice from the outdoor
unit grille. This condition will not affect the proper function
of the unit and will clear within a few days.

EMERGENCY HEAT

The EMERGENCY HEAT setting on your thermostat
refers to any supplementary heating appliance that may be
included in your home comfort system. Operation of the
EMERGENCY HEAT source may be required if heating
demands exceed the capacity of the heat pump, or if the heat
pump malfunctions.
The red light on your thermostat will illuminate if the
EMERGENCY HEAT switch is moved from NORMAL to
the EMERGENCY HEAT setting. This indicates that the
heat pump is off and the supplemental heating appliance is
selected for operation.
Also, if your particular model of heat pump includes an "effi-
ciency alarm" circuit, the red light will glow if the compres-
sor malfunctions. Call your dealer for immediate service if
you suspect trouble.
During the heating season, switch to EMERGENCY HEAT
if the electricity to your outdoor unit has been off for more
than 30 minutes for any reason (i.e., power outage). Leave
the switch in the EMERGENCY HEAT position for an
amount of time equal to that during which the power was
off. It isn't necessary to exceed 12 hours. If you cannot
determine how long the power has been off, leave the
switch in the EMERGENCY HEAT position for 8 hours.
NOTE: The EMERGENCY HEAT switch is effective only
when the SYSTEM switch is set at the HEAT or AUTO
position.

PERFORMING ROUTINE MAINTENANCE

With the proper maintenance and care, your heat pump unit
will operate economically and dependably. Maintenance can
be accomplished easily by referring to the following direc-
tions. However, before performing maintenance, consider
these important safety precautions:
• DISCONNECT ALL ELECTRICAL POWER TO THE AIR
CONDITIONER BEFORE REMOVING ACCESS PANELS
TO PERFORM MAINTENANCE. Disconnect power to both
the indoor and outdoor units. NOTE: THERE MAY BE
MORE THAN 1 ELECTRICAL DISCONNECT SWITCH.
• ALTHOUGH SPECIAL CARE HAS BEEN TAKEN TO
MINIMIZE SHARP EDGES IN THE CONSTRUCTION OF
YOUR UNIT, BE EXTREMELY CAREFUL WHEN HAN-
DLING PARTS OR REACHING INTO THE UNIT.
CHECK THE AIR FILTER
A dirty air filter will cause excessive strain on the compres-
sor and blower motor. This can cause the components to
overheat and automatically shut down. In the extreme, the
components will fail and need to be replaced. To avoid inef-
ficient or failed operation of your unit, CHECK THE FIL-
TER(S) EVERY 3 TO 4 WEEKS. Replace filter(s) when
necessary, or clean the filter(s) if you have the reusable
type.
Fig. 3—Main Electrical Disconnect
Disposable filters should be replaced by similar, new filters
of the same dimensions.
Reusable, permanent filters should be washed in a solution
of cold water and mild detergent, then rinsed and thorough-
ly dried. THE FILTER MUST BE COMPLETELY DRY
BEFORE BEING REINSTALLED. To avoid prolonged
shutdown of your unit while a filter is drying, you should
have an extra filter on hand. This would allow you to rotate
between the 2 with minimal downtime for your comfort sys-
tem. Extra filters may be purchased from your dealer.
There are no filters in the outdoor unit of a split system. If
your indoor unit is a gas or oil furnace, refer to your furnace
User's Manual for filter location and procedures for replace-
ment or cleaning.
If your system includes an indoor fan coil unit, the filter may
be located in the unit where it connects with the return-air
duct or plenum. (See Fig. 4.) Remove the filter cover plate
by sliding latches toward center of plate. Lift filter to clear
lower flange. Filter is spring-loaded and will "pop out." Rein-
stall filter, being certain to secure filter behind lower flange.
When reinstalling cover plate, secure plate behind upper
flange then slide tabs outward.
Fig. 4—Removing Filter
from Fan Coil Unit
4