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B-Filters
GCS16 units require field provided field installed filters.
Filters should be installed in the return air duct. A filter kit is
available for downflow discharge applications. Filters
should be checked monthly (or more frequently in severe
use) and cleaned or replaced regularly. Take note of the
AIR FLOW DIRECTION" marking on the filter frame
when reinstalling.
NOTE - Filters must be U.L.C. certified or equivalent
for use in Canada.
C-Heat Exchanger
1- Visually check all air and exhaust passages regularly.
They must be clean and clear of debris and dirt accu
mulation.
2- Periodically check heat exchanger (once every few
heating seasons). Remove unit side panel adjacent to
heat exchanger (GCS16/GCS16R) or top panel
(GCS16H). Inspect heat exchanger casting (primary)
and tailpipe (secondary) for cracks. Replace if
cracked. Refer to Heating System Service Checks"
section for heat exchanger access and removal pro
cedure.
3- Inspect burner plate gasket and burner cone for dete
rioration. Replace if necessary. Refer to Heating Sys
tem Service Checks" section for heat exchanger re
moval and burner manifold assembly removal proce
dures.
4- Inspect gasket(s) between tailpipe (secondary) and
combustion air blower for deterioration. Replace if
necessary.
D-Burner
1- Before each heating season and periodiically thereaf
ter, examine the burner flame for proper appearance.
2- Before each heating season examine the burner and
flue for any deposits or blockages (rodent nest, wasp
nest, etc.) which may have occurred.
3- Clean burner as follows:
a-Turn off both electrical power and gas supply to the
unit.
b-Remove the access panel to the burner compart
ment.
c-Remove the burner as outlined in section VII-H-In
shot Burner."
d-Slide burner off orifice. Remove all debris from burn
er. Remove debris from all passages within reten
tion ring.
e-Remove spark/sensor electrode assembly from
burner plate. Check the spark electrode and flame
sensing electrode gaps. Reinstall the burner and
ensure that the burner head is lined up correctly
with flame spreader. Replace the four screws se
curing the gas/burner manifold to the burner plate.
IMPORTANT - BURNER ENCLOSURE MUST BE
REASSEMBLED TAKING CARE NOT TO CREATE
AIR LEAKS DUE TO MISALIGNMENT OF PARTS.
AIR LEAKS WILL ADVERSELY AFFECT UNIT PER
FORMANCE.
Secure the gas manifold bracket and double check
burner head alignment with flame spreader.
f- Restore electrical power and gas supply. Follow the
lighting instructions attached to the unit and check
the burner flame. Flame should be blue with clear
yellow streaking. If the burner does not appear to be
operating correctly stop the unit, disconnect power
and gas and adjust as necessary. Replace the ac
cess panel when finished.
E-Combustion Air Blower
All GCS16s use combustion air blowers with prelubri
cated, sealed, stainlesssteel ball bearings.
A differential pressure switch (combustion air prove
switch) is used to prove combustion air blower operation.
If the blower is obstructed, the switch will not close and the
ignition control will be locked out.
Under normal operating conditions, the combustion air
blower wheel should be inspected prior to the heating sea
son to determine if cleaning is necessary. With the power
supply disconnected, the condition of the blower wheel
can be determined by looking through the vent opening.
Maintenance consists of:
1- Checking prove switch. Prove switch should close at
the factory setting shown in table 3.
2- Check the combustion air pressure switch hose for
blockage or deterioration. Replace if necessary.
3- Position hose so accumulated condensate can drain
from the switch into blower housing.
4- Clean combustion air blower assembly.
Combustion air blowers on 125,000 Btuh heat exchangers
can be removed but cannot be disassembled for cleaning.
Do not attempt to disassemble the blower.
To clean combustion air blower:
1- Shut off power supply and gas to the unit.
2- Remove the screws retaining the vent cap and com
bustion air blower to the end panel. Clean the vent cap
as necessary.
