Electrical; General Inspection; Vent Pipe Combustion Air Intake; Condensate Line/Trap Assembly - Thermo Pride CMA4-50D36N Installation And Service Manual

Label wires prior to disconnection when servicing controls. Wiring
:
errors can cause improper and dangerous operation.
A. ELECTRICAL:
1. Check diagnostic code through view port prior to removing access door.
2. Check all wiring for loose connections and any signs of damage or unusual
wear.
3. Check for correct voltage at the furnace when operating.
4. Check amp-draw on blower motor and inducer motor to assure they are not
exceeding name plate amp rating.
5. Check for correct operation and proper settings (if manually adjustable) of all
controls.
Shut off gas and disconnect power before continuing.
B. GENERAL INSPECTION

1. VENT PIPE COMBUSTION AIR INTAKE

a. Remove the vent and check the vent for signs of carbon build-up and for
signs of blockage.
b. The entire length of vent and combustion air inlet pipe and their
terminations should be inspected for restrictions, loose or loosely sealed
joints, carbon build-up. Also inspect the outside vent and combustion air
terminals and ensure that they are clear and unobstructed.

2. CONDENSATE LINE/TRAP ASSEMBLY

The condensate line must be inspected to make sure it is not blocked. All of the
lines should be flushed with water to remove any build-up of sediment.

3. BURNERS

If it appears that material is accumulating in the burner box, the burner box cover
can be removed and the box and burners can be vacuumed. (NOTE: The igniter
& flame sensor must be removed before removing the assembly.) If necessary,
the burner assembly can be removed by taking out the two screws/one on each
bracket at the bottom of the box. Assembly must be pulled & tilted away from the
burner compartment in order to remove from box. If necessary, the individual
tubes can be cleaned out by using compressed air.Care must be taken not to
damage the igniter.

4. INDUCER BLOWER ASSEMBLY

Inspect the pressure switch and drain tubing connections and inspect the
blower/assembly for warpage, deterioration and carbon or other build-up. If
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