Start Up Checks; Cooling Mode - Lennox Merit Series 13HPX Units Installation Instructions Manual

Thermostat Operation
See the ComfortSense
manual for instructions on how to operate your thermostat.
Heat Pump Operation
Your new Lennox heat pump has several characteristics that
you should be aware of:
•
Heat pumps satisfy heating demand by delivering large
amounts of warm air into the living space. This is quite
different from gas‐ or oil‐fired furnaces or an electric
furnace which deliver lower volumes of considerably
hotter air to heat the space.
•
Do not be alarmed if you notice frost on the outdoor coil
in the winter months. Frost develops on the outdoor coil
during the heating cycle when temperatures are below
45°F (7°C). An electronic control activates a defrost
cycle lasting 5 to 15 minutes at preset intervals to clear
the outdoor coil of the frost.
•
During the defrost cycle, you may notice steam rising
from the outdoor unit. This is a normal occurrence. The
thermostat may engage auxiliary heat during the defrost
cycle to satisfy a heating demand; however, the unit will
return to normal operation at the conclusion of the
defrost cycle.
13HPX Start-Up and Performance Checklist
Customer
Indoor Unit Model
Outdoor Unit Model
Notes:

START UP CHECKS

Refrigerant Type:
Rated Load Amps:
Condenser Fan Full Load Amps

COOLING MODE

Suction Pressure:
Supply Air Temperature:
System Refrigerant Charge (Refer to manufacturer's information on unit or installation instructions for required
subcooling and approach temperatures.)
Subcooling:
Approach:
Indoor Coil Temperature Drop (18 to 22°F)
®
7000 thermostat homeowner
Liquid Pressure:
Ambient Temperature:
Saturated Condensing Temperature (A)
minus Liquid Line Temperature (B)
minus Outdoor Air Temperature (B)
minus Supply Air Temperature (B)
The heat pump is equipped with a compressor crankcase
heater which protects the compressor from refrigerant
slugging during cold weather operation.
If power to your unit has been interrupted for several hours
or more, set the room thermostat selector to the
EMERGENCY HEAT setting to obtain temporary heat
without the risk of serious damage to the heat pump.
In EMERGENCY HEAT mode, all heating demand is
satisfied by auxiliary heat; heat pump operation is locked
out. After a six‐hour compressor crankcase warm‐up period,
the thermostat can be switched to the HEAT setting and
normal heat pump operation may resume.
If your system fails to operate, check the following before
calling for service:
•
Verify room thermostat settings are correct.
•
Verify that all electrical disconnect switches are ON.
•
Check for any blown fuses or tripped circuit breakers.
•
Verify unit access panels are in place.
•
Verify air filter is clean.
•
If service is needed, locate and write down the unit
model number and have it handy before calling.
Address
Serial
Serial
Actual Amps
Actual Amps:
Return Air: Temperature:
Liquid Line Temperature (A)
Return Air Temperature (A)
Page 16
Extended Power Outage
Preservice Check
Rated Volts
Actual Volts
A — B =
A — B =
A — B = COIL TEMP DROP
SUBCOOLING
APPROACH