Dunkirk Q90-200 Installation, Operation & Maintenance Manual page 29

Annual Shut Down Procedure (End Of Each Heating
Season)
Follow the instructions in "To Turn Off Gas To
1.
Appliance" page 23 of this manual.
If heating system is to remain out of service during
2.
freezing weather, and does not contain antifreeze,
drain system completely. If boiler will be exposed
to freezing temperatures, drain condensate lines.
Otherwise, do not drain system or boiler.
Annual Examination And Cleaning Of Boiler
Components
The following service procedures must be
performed only by a qualifi ed service agency.
Boiler owner should not attempt these
procedures.
Before servicing, turn off electrical power to boiler at
1.
service switch. Close manual gas valve to turn off gas
supply to boiler.
Examine fl ue passages by removing blower assembly
2.
from casting as shown in the separately provided
"Repair Parts Manual." The procedure for examining
and cleaning the burner is described below.
Any buildup of sediment or aluminum oxide (white powdery
or fl aky substance) in the fl ue passages must be cleaned as
follows:
A. Remove jacket front and top panels.
B. Confi rm that manual gas valve is closed and
disconnect gas line to gas valve at union.
C. Disconnect wires to gas valve and igniter.
D. Remove air inlet assembly from gas valve.
E. Loosen but do not remove fi ve nuts attaching
blower adapter assembly to boiler.
F. Remove two igniter screws and very carefully
remove the igniter. The igniter element is very
sensitive. Do not touch the igniter element with
your fi ngers or hands as oils or debris will cause
premature failure.
G. Remove fi ve nuts and blower adapter assembly.
Remove burner and gaskets.
MAINTENANCE AND CLEANING
NOTICE
H. Aluminum oxide deposits are water soluble and
may be rinsed away with spraying or running
water.
I. Use a fl exible handle nylon brush to loosen
sediment and aluminum oxide on all exposed
heating surfaces of boiler (see "Repair Parts
Manual" for diagram). Be sure that brush does not
get stuck in heat exchanger!
J. After brushing and rinsing, remove any remaining
loosened sediment using a shop vacuum with a
snorkel attachment.
K. Inspect burner for any foreign matter in the fl ame
ports or inside the burner. Any foreign matter
should be removed by blowing with compressed air
or vacuuming.
L. Reinstall burner and gaskets and position blower
adapter assembly over studs. Install fi ve nuts but
do not tighten. Reinstall igniter and igniter gasket
and fasten with two screws. The igniter element
is very sensitive. Do not touch the igniter element
with your fi ngers or hands as oils or debris will
cause premature failure Tighten fi ve nuts holding
blower adapter assembly.
M. Connect gas line to gas valve; air inlet assembly
to gas valve (using 2" x 1½" fl exible coupling);
pressure switch hose to gas valve and air inlet
assembly; 2" fl exible coupling to boiler exhaust
port; igniter wires; and gas valve wires.
Visually inspect the condensate trap. Refer to repair
3.
parts diagrams. Any foreign material or debris that is
visible in the condensate lines needs to be cleaned out
as described below.
A. Inspect for sediment or blockage.
B. Flush out with water or vacuum.
C. Follow the instructions under
Piping" (pages 10-12) of this document for fi lling
condensate trap with water.
Inspection of the fl ue connector requires the following
4.
steps. Refer to the "Repair Parts Manual" for diagram.
A. Loosen clamp on draft inducer end of 2" fl exible
coupling that connects vent tee to exhaust port.
B. Inspect interior of vent tee. Any buildup of
sediment on the inside surface must be cleaned.
C. Reconnect the 2" fl exible coupling to the draft
inducer outlet.
29
"Near Boiler