GVZC20 Service Manual

SERVICING
75
CTK04 ADDENDUM
CTK04 ADDENDUM
9. Once satised with BOOST MODE adjustments,
navigate to the HOME screen by selecting the Previous
Menu button three times then selecting HOME.
DEHUMIDIFICATION
The thermostat reads the indoor humidity level and allows
the user to set a dehumidication target based on these
settings. The thermostat controls the humidity level of the
conditioned space using the cooling system. Dehumidica-
tion is engaged whenever a cooling demand is present and
structural humidity levels are above the target level. When
this condition exists, the circulating fan output is reduced,
increasing system run time, over cooling the evaporator coil
and ultimately removing more humidity from the structure
than if only in cooling mode. The CTK04 also allows for an
additional overcooling limit setting from 0°F to 3°F setup
through the Installer Option menu (directions following).
This allows the cooling system to further reduce humidity by
lowering the temperature up to 3°F below the cooling set-
point in an attempt to better achieve desired humidity levels.
By default, dehumidication needs to be turned ON at
the thermostat via the Dehumidication Equipment menu.
Dehumidication can be activated at the original equipment
setup by selecting the A/C with Low Speed Fan button in
the Dehumidication Menu. Availability can be veried by
pressing MENU on the home screen. Scroll down and if
a Dehumidication button is present, dehumidication is
activated.
If Dehumidication is not available in the menu then it must
be enabled through the Installer Options menu. Use the
following procedure to enable and disable dehumidication:
1. On the CTK04 HOME screen select MENU.
2. From the MENU screen, scroll down and select Installer
Options.
3. Enter installer password if known.
a. The password is the thermostat date code and can
be obtained by selecting the red Cancel button and
selecting the Dealer Information button.
b. Once recorded, click the green OK button and return
to the previous step.
4. Select YES to continue.
5. Select View / Edit Current Setup.
6. Scroll down and select Dehumidication.
7. Once open select Dehumidication Equipment: None.
8. From the Dehumidication Menu select A/C with Low
Speed Fan and click the green Done button.
9. Additional Dehumidication operational options can be
selected in the resulting window.
10.Once satised with the selection, navigate to the HOME
screen by selecting the Done button and selecting Yes to
verify the changes.
11.Select Previous Menu, then the HOME to return to the
main menu.
DEHUMIDIFICATION TIPS*
For e󰀨ective dehumidication operation:
• Ensure “Dehum” is NOT set to “OFF” through the
Installer Options menu and/or in the ComfortNet User
Menu (COOL SETUP).
- If except OFF, the Dehumidication menu should be
visible in the main menu.
• Verify the cooling airow prole is set to “Prole D”.
- See the Cool Set-up section of the Installation Manual
for complete airow prole details.
- By default, “Dehum” is STD and the cooling airow
prole is set to “Prole D”.
• For additional dehumidication control, airow settings
are eld adjustable and can be ne-tuned to a value that
is comfortable for the application from a range of Cool
Airow Trim.
• In addition, the system can have Enhanced Dehumidi-
cation operation in setting “A”, “B”, or “C” of “Dehum”
based on dehumidication demand..
- See the DEHUMIDIFICATION SELECT section for
more detail.
* The specication of *VZC200241AF, 0361AE,
0481AE, and 0601AE or earlier models are di󰀨erent
from this specication. For details, see the
Installation Manual or Service Manual that matches
the Major and Minor revision of model name.