Access & passwords: Furnace tips

Short, practical technician tips on access & passwords for furnace. Check each one against the manual for your exact model before acting.

App access code and alternate connection

Goodman · All 34.5in chassis furnaces with CoolCloud app

The app asks for a 3-digit access code shown on the three 7-segment displays, visible through the sight glass near the board. Three wrong entries cause a new code to show. Option 2 is to remove the door and read the digits with power on. This power cycles the control, and the code stays active briefly after a power cycle.

1. Read the 3-digit code through the sight glass, or remove the door with power on and read it there.
2. Enter the code in the app when prompted.
3. If the code is entered wrong three times, a new code appears on the control; read the new code.
4. Use the thermostat task method instead if you do not want to power cycle the control.

Open the furnace advanced menus from a ComfortNet thermostat

Goodman · GMVC95/AMVC95 upflow and *CVC9 counterflow two-stage furnaces

Fault history, model data and blower set-up are reached through the CTK01 thermostat.

1. On the home screen touch Menu.
2. Hold Installer Config about 3 seconds (thermostat options).
3. Hold Installer Config again about 3 seconds (advanced installer menu). The fault screen shows first.
4. Use - / + to pick the furnace, then Installer Config to enter its submenus.
5. Menu backs out one level. Run Schedule exits to the home screen.

Unit address shown at power-up

Goodman · All 34.5in chassis furnaces

At power-up the control shows the unit address as a two-digit number on the 2nd and 3rd 7-segment characters. After start-up it moves to the Status Menu.

1. Apply power and watch the 2nd and 3rd digits for the unit address during start-up.

Changing dipswitches under the protective cover

Rheem · 96V and 96MDV integrated furnace control dipswitches S1, S2, S3

The dipswitches have a protective cover that must be pierced to change a switch position. Use a pen or similar tool. This is normal and does not damage the dipswitch.

1. Use a pen or similar tool to press through the cover and set the switch.

Blower door interlock

Trane · Furnace service access

The blower door switch cuts power to the blower and gas valve when the door is removed.

1. Disconnect power before removing the blower door.
2. Keep all panels closed during operation to avoid fume escape.