OPERATING YOUR UNIT
The operation of your system is controlled by the indoor tempera- ture control (for 674B, either a Thermidistat™ or dual fuel thermostat is required). You simply adjust the thermostat and it maintains the indoor temperature at the level you select. Most thermostats of heating and cooling systems have 3 controls: a temperature control selector, a FAN control, and a SYSTEM or MODE control. Refer to your thermostat owner’s manual for more information.
To better protect your investment and to eliminate unnecessary service calls, familiarize yourself with the following facts:
1.During heat pump heating, increasing the thermostat setting more than 2°F may cause the supplemental gas heat to be turned on for a short period of time to satisfy the thermostat. Needless use of the supplementary heat reduces potential energy savings.
2.Ice or frost tends to form on the coil during winter heating operation. Your heat pump is designed to automatically melt the ice. When in this defrost cycle, it is normal for steam or fog to rise from the outdoor unit. Do not be alarmed!
I.COOLING MODE
With the SYSTEM or MODE control set to COOL, your unit will run in cooling mode until the indoor temperature is lowered to the level you have selected. On extremely hot days, your unit will run for longer periods at a time and have shorter “off” periods than on moderate days.
II. HEAT PUMP HEATING MODE
With the SYSTEM or MODE control of your indoor thermostat set to HEAT, your unit will run in heat pump heating mode until room temperature is raised to the level you have selected. Of course, your system will run for longer periods to maintain a comfortable environment on cooler days and nights than on moderate ones.
III. GAS HEAT MODE
Your heat pump is your primary heating source. Your system is also be equipped with a supplemental gas heating source. On cold days and nights, your system will automatically turn on the supplemental heat in order to maintain the level of comfort you have selected.
When your heat pump needs additional heat to keep you comfort- able, your Bryant electronic thermostat will turn on the supple- mental gas heat and display the “AUX HT” message.
IV. DEFROST MODE
When your heat pump is providing heat to your home or office and the outdoor temperature drops below 45°F, moisture may begin to freeze on the surface of the 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
The defrost mode starts at a preset time interval of 30 minutes, although, it may be reset to 60, 90 or 120 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 coil, or after a maximum of 10 minutes in defrost mode, the unit automatically switches back to normal heating operation.
Do not be alarmed if steam or fog appears at the outdoor unit during defrost mode. 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 unit grille. This is normal for these weather conditions. Do not attempt to remove the ice from the unit grille. This condition will not affect the proper function of the unit and will clear within a few days.
V. EMERGENCY HEAT MODE
If you should have problems with the heat pump portion of your system, this mode allows your supplemental gas heating source to keep your home or office warm until your heat pump can be serviced.
MAINTENANCE AND SERVICE
This section discusses maintenance that should be performed on your system. Most maintenance should be performed by your dealer. You, as the owner, may wish to handle some minor maintenance for your new unit.
A. Routine Maintenance
All routine maintenance should be handled by skilled, experienced personnel. Your dealer can help you establish a standard proce- dure.
For your safety, keep the unit area clear and free of combustible materials, gasoline, and other flammable liquids and vapors.
To assure proper functioning of the unit, flow of condenser air must not be obstructed from reaching the unit. Clearance from the top of the unit is 48 in. Clearance of at least 36 in. is required on sides except the power entry side (42 in. clearance) and the duct side (12 in. minimum clearance).
B. Maintenance and Care for the Equipment Owner
Before proceeding with those things you might want to maintain yourself, please carefully consider the following:
WARNING: 1. TURN OFF ALL ELECTRICAL POWER TO YOUR UNIT AND IN- STALL
MAINTENANCE. ELECTRIC
SHOCK COULD CAUSE SERIOUS INJURY OR DEATH.
2.When removing access panels or performing mainte- nance functions inside your unit, be aware of sharp sheet metal parts and screws. Although special care is taken to keep sharp edges to a minimum, be extremely careful when handling parts or reaching into the unit.
AIR FILTERS
The air filter(s) should be checked at least every 3 or 4 weeks and changed or cleaned whenever it becomes dirty. Dirty filters produce excessive stress on the blower motor and can cause the motor to overheat and shut down.
This unit must have air filters in place before it can be operated. These filters can be located in one of at least two places. In many applications the installer will provide return air filter grilles mounted on the wall or ceiling of the conditioned structure. In the instance of filter grilles, the filters can simply be removed from the grille and replaced.
The other typical application is an accessory filter rack installed inside the unit itself. The following information is given to assist in changing filters used in these internal filter racks.
Table 1 indicates the correct filter size for your unit. Refer to Fig. 2 to access filters installed in the accessory filter rack.
TABLE 1—INDOOR-AIR FILTER DATA
UNIT SIZE | FILTER SIZE |
20x20x1 | |
674B036 | 20x24x1 |
24x30x1 | |
|
|
To replace or inspect filters in accessory filter rack (See Fig. 2):
