Lennox International Inc G61MP Series Units Service, Electrical SHOCK, Fire Or Explosion Hazard

Service

WARNING

ELECTRICAL SHOCK, FIRE,

OR EXPLOSION HAZARD.

Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage.

Improper servicing could result in dangerous opera- tion, serious injury, death, or property damage. Before servicing, disconnect all electrical power to furnace.

When servicing controls, label all wires prior to dis- connecting. Take care to reconnect wires correctly. Verify proper operation after servicing.

At the beginning of each heating season, system should be checked as follows by a qualified service technician: Blower

Check the blower wheel for debris and clean if necessary. The blower motors are prelubricated for extended bearing life. No further lubrication is needed.

WARNING

The blower access panel must be securely in place when the blower and burners are operating. Gas fumes, which could contain carbon monoxide, can be drawn into living space resulting in personal inju- ry or death.

Filters

All G61MP filters are installed external to the unit. Filters should be inspected monthly. Clean or replace the filters when necessary to ensure proper furnace operation. Table 3 lists recommended filter sizes.

Exhaust and air intake pipes

Check the exhaust and air intake pipes and all connections for tightness and to make sure there is no blockage. NOTE − After any heavy snow, ice or frozen fog event the furnace vent pipes may become restricted. Always check the vent system and remove any snow or ice that may be obstructing the plastic intake or exhaust pipes. Electrical

1 − Check all wiring for loose connections.

2 − Check for the correct voltage at the furnace (furnace operating).

3 − Check amp−draw on the blower motor.

Motor Nameplate__________Actual__________

Winterizing and Condensate Trap Care 1 − Turn off power to the unit.

2 − Have a shallow pan ready to empty condensate water.

3 − Remove the drain plug from the condensate trap and empty water. Inspect the trap then reinstall the drain plug.

Cleaning Heat Exchanger

If cleaning the heat exchanger becomes necessary, follow the below procedures and refer to figure 1 when disassem- bling unit. Use papers or protective covering in front of fur- nace while removing heat exchanger assembly.

1 − Turn off electrical and gas supplies to the furnace.

2 − Remove the upper and lower furnace access panels. 3 − Mark all gas valve wires and disconnect them from

valve.

4 − Remove gas supply line connected to gas valve. Re- move gas valve/manifold assembly.

5 − Remove sensor wire from sensor. Disconnect 2-pin plug from the ignitor.

6 − Disconnect wires from flame roll−out switches.

7 − Remove burner box cover and remove four burner box screws at the vestibule panel and remove burner box. Set burner box assembly aside.

NOTE − G61MP−135 units are secured to the vestibule panel by two additional screws. These screws must be removed for servicing; however it is not necessary to replace the screws.

NOTE − If necessary, clean burners at this time. Follow procedures outlined in Burner Cleaning section.

8 − Loosen three clamps and remove flexible exhaust tee. 9 − Remove 3/8 inch rubber cap from condensate drain

plug and drain. Replace cap after draining.

10 − Disconnect condensate drain line from the conden- sate trap. Remove condensate trap (it may be neces- sary to cut drain pipe). Remove screws that secure condensate collars to either side of the furnace and re- move collars. Remove drain tubes from cold end header collector box.

11 − Disconnect condensate drain tubing from flue collar. Remove screws that secure both flue collars into place. Remove flue collars. It may be necessary to cut the exiting exhaust pipe for removal of the fittings.

12 − Mark and disconnect all combustion air pressure tub- ing from cold end header collector box.

13 − Mark and remove wires from pressure switches. Re- move pressure switches. Keep tubing attached to pressure switches.

14 − Disconnect the 3-pin plug from the combustion air in- ducer. Disconnect the two wires to the backup secon- dary limit, if applicable. Remove four screws which se- cure combustion air inducer to collector box. Remove combustion air inducer assembly. Remove ground wire from vest panel.

15 − Remove electrical junction box from the side of the fur- nace.

16 − Mark and disconnect any remaining wiring to heating compartment components. Disengage strain relief bushing and pull wiring and bushing through the hole in the blower deck.

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