Carrier 58MVB, 58MTB, 58MCB manual 3940, Heading South for the WINTER?, DON’T Forget Your Furnace

Check the combustion-air intake and vent pipe on the outside of your home for blockage.

When dirt, soot, scale, or rust is allowed to build up, your furnace can suffer a loss of efficiency and perform improperly. Accumu- lations on the main burners can result in firing out of normal sequence. This delayed ignition creates an alarmingly loud sound.

!CAUTION

UNIT OPERATION HAZARD

Failure to follow this caution may result in minor property damage.

If your furnace makes an especially loud noise when the main burners light, shut down your fur- nace and call your dealer.

To inspect the combustion area and vent system, you will need a flashlight. Refer to Fig. 3 or 4, and proceed as follows:

1.Turn off the gas and electrical supplies to the furnace and remove the main furnace door. (See Fig. 11, 12, and 13.)

2.Remove burner enclosure front. (See Fig. 39 or 40.)

Inspect the gas burners, igniter area, and remainder of furnace for dirt, rust, soot, or scale.

!WARNING

CARBON MONOXIDE POISONING HAZARD Failure to follow this warning could result in per- sonal injury or death.

If dirt, rust, soot, or scale accumulations are found, call your dealer. Do not operate your furnace.

3.Inspect the combustion-air and vent PVC pipes for sags, holes, cracks, water leaks, blockage or disconnections. Horizontal portions of pipes must slope downward toward furnace.

HEADING SOUTH FOR THE WINTER?

DON’T FORGET YOUR FURNACE!

!CAUTION

UNIT AND PROPERTY DAMAGE HAZARD

Failure to follow this caution may result in damage to the furnace and other property damage.

If the furnace is installed in an unconditioned space where the ambient temperatures may be 32°F or lower, freeze protection measures must be taken to prevent minor property or product damage.

Since the furnace uses a condensing heat exchanger, some water will accumulate in the unit as a result of the heat transfer process. Therefore, once it has been operated, it cannot be turned off and left off for an extended period of time when temperatures will reach 32°F or lower unless winterized. Follow these procedures to winterize your furnace:

1.Obtain propylene glycol (RV/swimming pool antifreeze or equivalent).

!CAUTION

UNIT COMPONENT DAMAGE HAZARD

Failure to follow this caution may result in damage to the furnace and other property damage.

Do not use ethylene glycol (Prestone II antifreeze coolant or equivalent). Failure of plastic components may occur.

2.Turn off electrical supply to the furnace. (See Fig. 22.)

3.Remove main furnace door. (See Fig. 25.)

4.Remove upper inducer housing drain connection cap. (See Fig. 42.)

Upflow

Downflow

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4.Reinstall burner enclosure front.

5.If your furnace is free of the above conditions, replace main furnace door and turn on electrical and gas supplies to the furnace. (See Fig. 18, 19, and 20.)

6.Start the furnace and observe its operation. Watch the burner flames to see if they are clear blue, almost transpar- ent. (See Fig. 41.) If you observe a suspected malfunction, or the burner flames are not clear blue, call your dealer.

42

43

5. Connect field-supplied 1/2-in. ID tube to upper inducer

41 10

housing drain connection.