Emergency Heat (Heating Heat Pump); Maintenance - Lennox CBX25UH Installation Instructions Manual

second heat sequencer can be connected with the first
sequencer to W1 on the thermostat. They may also be
connected to a second heating stage W2 on the
thermostat sub-base.

EMERGENCY HEAT (HEATING HEAT PUMP)

If the selector switch on the thermostat is set to the
emergency heat position, the heat pump will be locked out
of the heating circuit, and all heating will be electric heat (if
applicable). A jumper should be placed between W2 and E
on the thermostat sub-base so that the electric heat control
will transfer to the first‐stage heat on the thermostat. This
will allow the indoor blower to cycle on and off with the
electric heat when the fan switch is in the AUTO position.

Maintenance

IMPORTANT
Do not operate system without a filter. A filter is required
to protect the coil, blower, and internal parts from ex­
cessive dirt and dust. The filter is placed in the return
duct by the installer.
S
Inspect air filters at least once a month and replace or
clean as required. Dirty filters are the most common
cause of inadequate heating or cooling performance.
S
Replace disposable filters. Cleanable filters can be
cleaned by soaking in mild detergent and rinsing with
cold water.
S
Install new/clean filters with the arrows on the side
pointing in the direction of air flow. Do not replace a
cleanable (high velocity) filter with a disposable (low
velocity) filter unless return air system is properly sized
for it.
S
If water is seen dripping from the secondary drain line,
contact a qualified service technician. This is a sign of
a problem which must be investigated and corrected.
Cabinet Insulation
IMPORTANT
DAMAGED INSULATION MUST BE REPAIRED OR
REPLACED before the unit is put back into operation. In­
sulation loses its insulating value when wet, damaged,
separated or torn.
Matt‐ or foil-faced insulation is installed in indoor
equipment to provide a barrier between outside air
conditions (surrounding
humidity) and the varying conditions inside the unit. If the
insulation barrier is damaged (wet, ripped, torn or
separated from the cabinet walls), the surrounding
ambient air will affect the inside surface temperature of the
ambient temperature
cabinet. The temperature/humidity difference between the
inside and outside of the cabinet can cause condensation
on the inside or outside of the cabinet which leads to sheet
metal corrosion and subsequently, component failure.
REPAIRING DAMAGED INSULATION
Areas of condensation on the cabinet surface are an
indication that the insulation is in need of repair.
If the insulation in need of repair is otherwise in good
condition, the insulation should be cut in an X pattern,
peeled open, glued with an appropriate all-purpose glue
and placed back against the cabinet surface, being careful
to not overly compress the insulation so the insulation can
retain its original thickness. If such repair is not possible,
replace the insulation. If using foil‐faced insulation, any
cut, tear, or separations in the insulation surface must be
taped with a similar foil-faced tape.
1. CUT INSULATION IN X PATTERN
2. APPLY GLUE
3. PRESS GLUED TABS AGAINST CABINET
Figure 22. Repairing Insulation
Use of Air Handler During Construction
Lennox does not recommend the use of its air handler unit
during any phase of construction. Very low return air
temperatures, harmful vapors and operation of the unit
with clogged or misplaced filters will damage the unit.
Air handler units may be used for heating (heat pumps) or
cooling of buildings under construction, if the following
conditions are met:
S
A room thermostat must control the air handler. The
use of fixed jumpers is not allowed.
S
Air filter must be installed in the system and must be
maintained during construction.
S
Air filter must be replaced upon construction
completion.
S
The air handler evaporator coil, supply fan assembly
and
and duct system must be thoroughly cleaned following
final construction clean-up.
S
All air handler operating conditions must be verified
according to these installation instructions.
Page 18
GLUE -make sure there is
full coverage of glue on the
metal or insulation so there
are no areas where air
pockets may form which
can lead to sweating.