LLC GAS FURNACE HIGHBOY AND COUNTERFLOW USERS Information MANUAL

All installations and services must be performed by qualified service personnel.
14
MINIMUM FILTER AREA REQUIRED (LENGTH X WIDTH, SQ. IN.)
TABLE 1
FILTER TYPE MAXIMUM
RATE AIR
VELOCITY FURNACE MODEL
CDB1, CHB1-50
MDA1, MHA1-50
CHX1, CDX1-75
CDB1, CHB1-75
MDA1, MHA1-75
CHX1, CDX1-100
CDB1, CHB1-100
MDA1, MHA1-100
CHX1, CDX1-125
CDB1, CDB1-125
MDA1, MHA1-125
*THERMO PRODUCTS
SUPPLIED
PERMANENT FILTER
600 FT./MIN. 172 IN.
2
254 IN.
2
328 IN.
2
402 IN.
2
STANDARD
PERMANENT FILTER
500 FT./MIN. 208 IN.
2
304 IN.
2
394 IN.
2
484 IN.
2
DISPOSABLE TYPE
FILTER
300 FT./MIN. 344 IN.
2
506 IN.
2
656 IN.
2
804 IN.
2
* The Thermo Products supplied filter can be cut to size to fit other filter retention systems as
long as the minimum size requirement is met. NOTICE:
Any internal stiffeners used in the filter
must not be removed, although they can be cut to the length required.
C. VISUAL INSPECTION PROCEDURE
It is recommended that the homeowner/user conduct the following periodic visual inspection of
the furnace at the start of the heating season and monthly during the heating season.
: Call a qualified heating contractor to report suspected deficiencies (Do not attempt to
make repairs yourself!)
1. Turn off power to furnace.
2. Vent pipe, air intake pipe, and condensate system (CDB1/CHB1, CDX1/CHX1): Visually
check the vent and intake pipe as well as condensate lines both inside and outside the furnace
to make sure that vent intake joints and the condensate system are sealed. There should be no
sign of water leakage at any vent intake or condensate joints or anywhere inside the furnace.
Make sure that horizontal runs of vent pipe slope upward towards the outside. The inlet pipe
should slope slightly downward to prevent condensate build up. Any signs of damage,
leakage, deterioration, or possible blockage should be immediately reported to your dealer or
the local gas company.
It is recommended that the condensate removal system be cleaned annually by a qualified service
agency to insure its proper and continued operation.
Outside vent and outside combustion air termination: the outside vent terminations should be
inspected to insure that they are clear and free of obstruction by ice, snow, debris, of vegetation.
Any obstruction of the terminal should be carefully removed without damaging the vent terminal.
If ice has formed on the outside terminals themselves, it should be removed.