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10

Before you call for service...

...check for several easily--solved problems.

If insufficient heating or cooling is suspected:

( ) Check for sufficient airflow. Check the air filter for dirt. Check

for blocked return--air or supply--air grilles. Be sure they are open
and unobstructed. If these checks do not reveal the cause, call your

servicing dealer.

If your unit is not operating at all, check the following list for

easy solutions:

(

) Check to be sure that your thermostat temperature selector is

set below the indoor temperature during the cooling season or

above the indoor temperature during heating season. Be sure the

SYSTEM switch or MODE control is in the COOL or HEAT and
not OFF.
( ) If your unit still fails to operate, call your servicing dealer for
troubleshooting and repairs. Specify the model and serial numbers

of your unit. (Record them in this manual in the space provided.) If

the dealer knows exactly which unit you have, he may be able to
offer suggestions over the phone, or save valuable time through

knowledgeable preparation for the service call.

In Case of Trouble

If you perform the steps above and unit performance is still
unsatisfactory, shut off the unit and call your dealer.

MANIFOLD

BURNER

BURNER FLAME

C99021

Fig. 11 -- Monoport Burner

Copyright 2010 Carrier Corp.

S

7310 W. Morris St.

S

Indianapolis, IN 46231

Edition Date: 04/10

Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.

Catalog No: OM48EZ---VT---04

Replaces: OM48EZ--- VT--- 03

Summary of Contents for COMFORT 48EZ-A

Page 1: ...al Fuel System With Puron R 410A Refrigerant Single and Three Phase 2 5 Nominal Tons Sizes 24 60 Owner s Information Manual A09034 48EZ A Without Economizer A10077 48EZ A With Economizer Fig 1 Unit 48EZ A A09033 48VT A Without Economizer A10078 48VT A 48VT A with Economizer Fig 2 Unit 48VT A ...

Page 2: ...ent editions of the National Fuel Gas Code NFGC NFPA 54 ANSI Z223 1 and the National Electrical Code NEC NFPA 70 In Canada refer to the current editions of the National Standards of Canada CAN CSA B149 1 and 2 Natural Gas and Propane Installation codes and Canadian Electrical Code CSA C22 1 Recognize safety information This is the safety alert symbol When you see this symbol on the unit and in ins...

Page 3: ...ed gas heat electric heat pump systems that can utilize both the efficiency of heat pump heating and the comfort of gas heating The system will optimize for ideal heating depending on several factors This unit uses Puron the ozone friendly refrigerant for cooling and heat pump heating Starting or Shutting Off Unit NOTE Your combination heating cooling unit is equipped with an automatic direct spar...

Page 4: ...oceeding with the following steps 1 Set the temperature selector on room thermostat to highest temperature setting and set system SWITCH to OFF 2 Close the external manual shutoff valve if not already closed 3 Turn off the electrical power supply to the unit NOTE Heat Pump heating mode procedure is similar to electric cooling mode except thermostat mode is HEAT and thermostat must operate on first...

Page 5: ...5 55 STEP 1 STEP 2 CL O S E STEP 3 OFF ON MAIN STEP 4 STEP 7 OFF ON MAIN STEP 8 STEP 5 72 STEP 10 STEP 6 STEP 9 O P E N A07662 Fig 5 To Start Unit Gas Heat ...

Page 6: ...5 STEP 1 STEP 2 CL O S E STEP 3 OFF ON MAIN STEP 4 STEP 6 STEP 5 A07663 Fig 6 To Shut Off Unit Gas Heat 90 STEP 1 STEP 2 CL O S E 72 STEP 4 5 OFF ON MAIN STEP 3 A09194 Fig 7 To Start Unit Electric Cooling ...

Page 7: ... the top of the unit is 48 in 1219 mm Clearance of at least 36 in 914 mm is required on sides except the power entry side 42 in 1067 mm clearance and the duct side 12 in 305 mm minimum clearance Maintenance and Care for the Equipment Owner Before proceeding with those things you might want to maintain yourself please carefully consider the following FIRE EXPLOSION ELECTRICAL SHOCK AND CUT HAZARD F...

Page 8: ...5 mm 36 060 090 1 each 24 x 14 x 1 610 x 406 x 25 24 x 16 x 1 610 x 406 x 25 42 060 090 1 each 24 x 14 x 1 610 x 356 x 25 24 x 16 x 1 610 x 406 x 25 48 090 115 130 1 each 24 x 16 x 1 610 x 406 x 25 24 x 18 x 1 610 x 457 x 25 60 090 115 130 1 each 24 x 16 x 1 610 x 406 x 25 24 x 18 x 1 610 x 457 x 25 Units with bent indoor coil Large Chassis See Fig 10 1 Remove filter access door using a 5 16 in nu...

Page 9: ...one by a trained service person FIRE EXPLOSION HAZARD Failure to follow this warning could result in personal injury death and or property damage If your unit makes an especially loud noise when the main burners are ignited shut down the heating section and call your dealer WARNING BURN HAZARD Failure to follow this caution may result in personal injury Components in heating section may be hot aft...

Page 10: ... COOL or HEAT and not OFF If your unit still fails to operate call your servicing dealer for troubleshooting and repairs Specify the model and serial numbers of your unit Record them in this manual in the space provided If the dealer knows exactly which unit you have he may be able to offer suggestions over the phone or save valuable time through knowledgeable preparation for the service call In C...

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