Lennox International Inc Merit CBX25UH Series, Lennox Air Handler Maintenance, Cabinet Insulation

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 subbase.

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 subbase 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 exces­ sive dirt and dust. The filter is placed in the return duct by the installer.

SInspect 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.

SReplace disposable filters. Cleanable filters can be cleaned by soaking in mild detergent and rinsing with cold water.

SInstall new/clean filters with the arrows on the side pointing in the direction of airflow. Do not replace a cleanable (high velocity) filter with a disposable (low velocity) filter unless return air system is properly sized for it.

SIf water should start coming from the secondary drain line, a problem exists which should be investigated and corrected. Contact a qualified service technician.

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 ambient temperature and 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 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.

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.

1.CUT INSULATION IN X PATTERN

2.APPLY GLUE

3.PRESS GLUED TABS AGAINST CABINET

Figure 15. Repairing Insulation

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CBX25UH SERIES