Carrier SYNERGY 38YD - Manual (Page 4)

tem will operate until room temperature is raised to the level
you have selected. Of course, the heating unit will have to oper­
ate for longer periods to maintain a comfortable environment
on cooler days and nights than on moderate ones.
If supplementary heating source is a furnace, refer to your fur­
nace user’s manual for specific information on heating
operation.
DEFROST CYCLE
When your heat pump is providing heat to your home and the
outdoor temperature drops below 45 °F, moisture may begin to
freeze on the surface of the outdoor coil. If allowed to build up,
this ice would impede airflow across the coil and reduce the
amount of heat absorbed from the outside air. So, to maintain
energy-efficient operation, your heat pump has an automatic
defrost cycle.
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 ex­
ceed 12 hours. If you cannot determine how long the power has
been off, leave the switch in the EMERGENCY HEAT position
for 8 hours.
Fig. 4—Main Electrical Disconnect
The defrost cycle starts at a preset time interval of 90 minutes,
although it may be reset to either 30 or 50 minutes. Defrost will
start at the preset time only if the ice is sufficient to interfere
with normal heating operation.
After the ice is melted from the outdoor coil, or after a maxi­
mum of 10 minutes in the defrost mode, the unit will automati­
cally switch back to normal heating operation.
Do not be alarmed if steam or fog appears at the outdoor unit
during the defrost cycle. Water vapor from the melting ice may
evaporate 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 out­
door unit grille. This is normal for these weather conditions. 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.
SUPPLEMENTARY HEAT
Operation of the SUPPLEMENTARY HEAT source may be re­
quired if heating demands exceed the capacity of the heat
pump, or if the heat pump malfunctions.
The red AUX. light on your thermostat will glow if the SUP­
PLEMENTARY HEAT is in use. This indicates that the sup­
plemental heating appliance is selected for operation.
Also, if your particular model of heat pump includes an “effi­
ciency alarm” circuit, the MAL light will glow if the compressor
malfunctions. Call your dealer for immediate service if you sus­
pect trouble.
During the heating season, switch to EMERGENCY HEAT if
the electricity to your outdoor unit has been off for more than 30
Fig. 5—Removing Filter from
Fan Coil Unit
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 directions.
However, before performing maintenance, consider these im­
portant 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 ONE 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 compressor
and blower motor, causing the components to overheat and au­
tomatically shut down. In the extreme, the components will fail
and need to be replaced. To avoid inefficient or failed operation
of your unit, CHECK THE FILTER(S) EVERY 3 TO 4
WEEKS. Replace filter(s) when necessary, or clean the filter(s)
if you have the reusable t
5 rpe.
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 thoroughly
dried. THE FILTER MUST BE COMPLETELY DRY BE­
FORE BEING REINSTALLED. To avoid prolonged shutdown
of your unit while a filter is drying, you should have an extra
filter on hand, allowing you to rotate between the two with min­
imal downtime for your comfort system. 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 owner’s
manual for filter location and procedures for replacement or
cleaning.