Lennox International Inc G32Q5-125, G32Q3-100 Cleaning DuralokPlus TM Heat Exchanger, 275F 135C

2 - Have a shallow pan ready to empty condensate wa- ter. Avoid spilling water into the control box.

3 - Remove clamp from flue assembly and remove boot or cap. Empty water from cap. Visually inspect bot- tom of flue assembly. Replace boot and clamp.

4 - Remove boot from condensate trap and empty wa- ter. Inspect trap then replace boot.

Cleaning DuralokPlus TM Heat Exchanger

If cleaning the heat exchanger is necessary, follow the procedures below, and refer to figure 1 while you disas- semble the furnace. Place papers or protective covering in front of the furnace while you remove the heat exchang- er assembly.

1 - Turn off electrical and gas power supplies to fumaea. 2 - Remove upper and lower furnace access panels.

3 - Remove four screws around air intake fitting and lift intake pipe up and away.

4 - Loosen hose clamp securing top of flue transition to bottom of flue collar. Remove screw secudng flue collar to top cap and lift exhaust pipe and flue collar up and away.

5 - If electrical field make-up box is located inside the unit, it must be removed.

6 - Remove gas supply line connected to gas valve.

7 - Mark all gas valve wires and disconnect them from valve. Mark and remove wires from flame roll-out

switch.

8 - Remove top cap of unit.

9 - Remove sensor wire from SureLight_ control. Dis- connect 2-pin plug from the ignitor.

10 - Mark and disconnect pressure switch tubing from both sides of the pressure switch(es).

11 - Loosen two screws holding gas manifold support at vestibule panel.

12 - Remove four burner box screws at the vestibule pan- ei and remove burner box and gas valve/manifold as- sembly with bracket.

13 - Drain condensate trap. Disconnect condensate line from the outside of unit. Remove condensate line

from condensate trap by turning the adapter fitting counterclockwise. The fitting has standard right hand threads.

14 - Disconnect the drain hose from the flue transition to the elbow on the cold header (collector) box trap.

15 - Disconnect the 3-pin plug from the combustion air in- ducer at the blower deck. Remove four screwsfrom

combustion air inducer and remove flue transition

and inducerassemblyfrom cabinet. Take care notto lose the combustion air orifice.

16 - Mark and disconnectall remaining wires from heat- ing compartment components.

17 - Disengage strain relief bushing from blower deck and pull bushing and wires into the blower section.

18 - Remove the limit switch and the pressure switch(es) from the vestibule panel.

19 - Remove two screws from the front cabinet flange at the blower deck. Remove front screws from cabinet

at blower deck on left and right sides. Cabinet sides must be slightly spread to clear heat exchanger pas- sage.

20 - Remove screws along vestibule sides and bottom which secure vestibule panel and heat exchanger assembly to cabinet. Remove heat exchanger.

21 - Back wash heat exchanger with soapy water solu- tion or steam. If steam is used it must be below

275°F (135°C).

22-Thoroughly rinse and drain the heat exchanger. Soap solution can be corrosive so take care that en- tire assembly is completely dnsed.

23 - Reinstall heat exchanger into cabinet making sure that the clamshells of the heat exchanger assembly are resting in the notches of the support located at the rear of the cabinet. This can be viewed by remov- ing the indoor blower and examining through the blower opening.

24 - Resecure the supporting screws along the vestibule sides and bottom to the cabinet.

25 - Reinstall cabinet screws on sides and front flange at blower deck.

26 - Reinstall the limit switch and pressure switches on the vestibule panel.

27 - Route heating component wiring back through the hole in the blower deck and reinsert strain relief

bushing.Reconnect wires.

28 - Reinstall the combustion air inducer. Check to en- sure that the plastic orifice on the blower inlet has not

fallen out. See figure 1. Reconnect the 3-pin plug to the wire harness. Reinstall the flue transition in the

cabinet and reattech the drain tube. Route the drain tube below the combustion air inducer housing and to the elbow on the cold header (collector) box trap. See figure 35.

29 - Reinstall condensate line with adapter to condensate trap. Use fresh Teflon tape to ensure a leak-freejoint. Re-connectto condensate line outside of the unit.

30 - Reinstall the burner box. Tighten the screws holding the support bracket. It is important that the glass fiber

gasket not be damaged so it will provide a continu- ous seal between the burner box and the vestibule

panel.

31 - Reconnect pressure switch tubing by connecting the tubing from the bomer box to the barbed fitting on the bottom and the tubing from the combustion air induc- er to the barbed fitting on the top. See figure 35.

32 - Reconnect the sensor and ignitor wires.

33 - Reinstall top cap to unit.

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