Carrier 48TC*D08 Flue Gas Passageways, Combustion-AirBlower, LP Low Pressure Switch Installed

48TC

48TCDD08 only C08238

C08239

All 48TC*D except DD08

Fig. 31 - LP Low Pressure Switch (Installed)

IGC LP LPS

BRN C NO BRN J2-11

C MGV

IGC

GRA

J2-12

TSTAT

W2 PNK

C08285

Fig. 32 - LP Supply Line Low Pressure Switch Wiring

This switch also prevents operation when the propane tank level is low which can result in gas with a high concentration of impurities, additives, and residues that have settled to the bottom of the tank. Operation under these conditions can cause harm to the heat exchanger system. Contact your fuel supplier if this condition is suspected.

Flue Gas Passageways

To inspect the flue collector box and upper areas of the heat exchanger:

1.Remove the combustion blower wheel and motor as- sembly according to directions in Combustion-Air Blower section. (See Fig. 33.)

2.Remove the flue cover to inspect the heat exchanger.

3.Clean all surfaces as required using a wire brush.

Combustion-Air Blower

Clean periodically to assure proper airflow and heating efficiency. Inspect blower wheel every fall and periodically during heating season. For the first heating season, inspect blower wheel bi-monthly to determine proper cleaning frequency.

To access burner section, slide the sliding burner partition out of the unit.

To inspect blower wheel, shine a flashlight into draft hood opening. If cleaning is required, remove motor and wheel as follows:

1.Slide burner access panel out.

2.Remove the 7 screws that attach induced-draft motor housing to vestibule plate. (See Fig. 33.)

3.The blower wheel can be cleaned at this point. If ad- ditional cleaning is required, continue with Steps 4 and 5.

4.To remove blower from the motor shaft, remove 2 setscrews.

5.To remove motor, remove the 4 screws that hold the motor to mounting plate. Remove the motor cooling fan by removing one setscrew. Then remove nuts that hold motor to mounting plate.

6.To reinstall, reverse the procedure outlined above.

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