Dunkirk 90-50 Installation, Operation & Maintenance Manual page 43

K. Reinstall burner and mixer gasket and position mixer
assembly over studs. Install five (5) nuts but do not tighten.
Reinstall igniter and igniter gasket and fasten with two
(2) screws. Use care when installing the igniter. It is very
brittle! Tighten five (5) nuts holding mixer assembly.
L. Connect:
• Gas line to gas valve
• Condensate drain line to boiler
• Pressure switch hose to gas valve
• Air by-pass to mixer
• 1 ½" x 2" flexible coupling to air inlet and make sure to put
air baffle back to correct position
• Igniter wires
• Gas valve wires
Visually inspect condensate lines leading from the boiler
3.
sections and the vent tee to the condensate trap. Refer to repair
parts diagrams. Any foreign material or debris that is visible in
the condensate lines needs to be cleaned out as follows:
A. Raise condensate trap and drain condensate lines
completely.
B. Once the condensate trap is emptied of water, disconnect
condensate lines from the fittings on the boiler, the vent
tee, and the condensate outlet.
C. Remove the condensate trap and run cold water through
the condensate lines to thoroughly flush out any sediment
or debris in the lines.
D. Reinstall and connect the condensate trap, using the hose
clamps to secure the various condensate lines to their
fittings.
E. Follow the instructions under "NEAR BOILER PIPING"
for" filling condensate trap with water"
mainTenanCe and Cleaning
Inspection of the flue connector requires the following steps (Refer to
4.
the repair parts diagram.)
A.
B.
C.
D.
E.
43
Loosen the clamp on the draft inducer end of the 2"
flexible coupling that connects the vent tee to the draft
inducer. Disconnect (unplug) wiring harness from draft
inducer motor and draft inducer temperature safety switch.
Remove four (4) bolts that attach draft inducer to flue
connector.
Remove draft inducer and gasket from top of flue
connector.
Inspect interior of flue connector. Any buildup of sediment
or aluminum oxide on the inside surface must be cleaned.
Position the draft inducer gasket and the draft inducer
and fasten with four (4) screws. Be sure to connect ground
wire from draft inducer motor to one of the four mounting
screws.
Connect wiring harness leads to the draft inducer motor
and the draft inducer temperature safety switch.
Connect the 2" flexible coupling to the draft inducer outlet.