Honeywell commercialpro tb7220 ユーザーズマニュアル

63-2635—03

22

TROUBLESHOOTING (TABLE 11)

Display does not come on.

Thermostat is not being powered.

Check for 24 Vac between C and Rc.

Check that AAA batteries are installed correctly 

and are good.

Temperature settings do not 

change.

The upper or lower temperature limits were 

reached.

Check temperature setpoints.

Check ISU 0600 and 0610; modify as needed.

The keypad is fully locked.

Check ISU 0670 to change keypad locked 

options.

Heating or cooling does not come 

on.

Thermostat minimum off-time is activated. Wait up to five minutes for the system to respond.
System selection is not set to Heat or Cool. Set system Selection to correct position.
System type Selection is incorrect.

Check ISU 0170 and make sure correct System 

type is chosen.

Thermostat is calling for Heat 

(Heat on) or Cool (Cool on) but 

no heating or cooling is running.

Heating or cooling equipment is not 

operating.

Check wiring.

Check ISU 0170 and make sure correct system 

type is chosen.

Verify operation of equipment in System Test 

mode.

Heat does not turn on (Heat On is 

solid in the display).

Heating equipment failure.

Check for 24 Vac at the equipment on the 

secondary side of the transformer between power 

and common. If voltage is not present, check the 

heating equipment to find the cause of the 

problem.

Check for 24 Vac between the heat terminal (W) 

and transformer common. If 24 Vac is present, the 

thermostat is functional. Check the heating 

equipment to find the cause of the problem.

Loose or broken wire connection between 

thermostat and heating equipment.

Check for 24 Vac between the heat terminal (W) 

and transformer common. If voltage is not 

present, check wire connection (loose or broken) 

between the thermostat and the heating 

equipment.

Cooling does not turn on (Cool 

On is solid in the display).

Cooling equipment failure.

Check for 24 Vac at the equipment on the 

secondary side of the transformer between power 

and common. If voltage is not present, check the 

cooling equipment to find the cause of the 

problem.

Check for 24 Vac between the cool terminal (Y) 

and transformer common. If 24 Vac is present, the 

thermostat is functional. Check the cooling 

equipment to find the cause of the problem. 

Loose or broken wire connection between 

thermostat and cooling equipment.

Check for 24 Vac between the cool terminal (Y) 

and transformer common. If voltage is not 

present, check the wire connection (loose or 

broken) between the thermostat and the cooling 

equipment.

Fan does not turn on in a call for 

heat (electric furnace).

Fan Control in Heating is set to Gas or Oil 

Furnace (Setting 0180).

Set Fan Control in Heating to Electric Furnace 

(Setting 0180).

Heat pump puts out cool air in the 

heat mode and warm air in the 

cool mode.

Changeover Valve (ISU 0190) is not 

configured to match the changeover 

required by the installed heat pump.

Set Changeover Valve (ISU 0190) to match the 

changeover required by the installed heat pump.

Both the heating and cooling 

equipment are running at the 

same time.

The heating equipment is not a heat pump 

but the System Type (ISU 0170) is set to 

Heat Pump.

Set System Type (ISU 0170) to match the 

installed heating and/or cooling equipment.

Heating and cooling wires are shorted 

together.

Separate the shorted heating and cooling wires.