Burner; To Clean Burners; Combustion Air Discharge; Cleaning Flue Passages And Heating Elements - York DNH018 Installation Manual

66324-YIM-B-1004

BURNER

At the beginning of each heating season, make a visual
check of the main burner flame. If it is not possible to adjust
for the proper flame, the burners may need cleaning.

TO CLEAN BURNERS

Remove them from the furnace as explained in Burner
Instructions. Clean burners with hot water applied along top
of the burner.

COMBUSTION AIR DISCHARGE

Visually inspect discharge outlet periodically to insure soot
and dirt buildup is not excessive. If necessary, clean to main-
tain adequate combustion air discharge.
The manufacture recommends that the furnace system be
inspected once a year by a qualified service person.
CLEANING FLUE PASSAGES AND HEATING ELE-
MENTS
With proper combustion adjustment the heating element of a
gas fired furnace will seldom need cleaning. If the element
should become sooted, it can be cleaned as follows:
1. Remove the burner assembly as outlined in BURNER
INSTRUCTIONS.
2. Remove the screws securing the restrictor plate to the
tube sheet.
3. Using a wire brush on a flexible wand, brush out the
inside of each heat exchanger from the burner inlet and
flue outlet ends.
4. Brush out the inside of the restrictor plate to the tube
sheet.
5. If soot build-up is particularly bad, remove the vent motor
and clean the wheel and housing.
Unitary Products Group
6. After brushing is complete, blow all brushed areas with
air or nitrogen. Vacuum as needed.
7. Replace parts in the order they were removed in steps 1
through 3.

CHECKING SUPPLY AIR CFM

To check the supply air CFM after the initial balancing
has been completed:
1. Remove the two ¼ inch dot plugs in the duct panel.
2. Insert at least 8 inches of ¼ inch tubing into each of
these holes for sufficient penetration into the airflow on
both sides of the indoor coil.
3. Using an inclined manometer, determine the pressure
drop across the dry evaporator coil. Since the moisture
on an evaporator coil may vary greatly, measuring the
pressure drop across a wet coil under field conditions
would be inaccurate. To ensure a dry coil, the compres-
sors should be deactivated while the test is being run.
4. Knowing the pressure drop across a dry coil, the actual
CFM through the unit can be determined from the curve
in Coil Delta P vs. Supply Air CFM figure.
Failure to properly adjust the total system air quan-
tity can result in extensive system damage.
After readings have been obtained, remove the tubes
and reinstall the two ¼ inch plugs removed in Step 1.
De-energize the compressors before taking any test
measurements to ensure a dry indoor coil.
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