Max Defrost By Weather; Automatic Max Defrost Rule - Lennox iComfort Wi-Fi Setup Manual

Next defrost cycle
should run MAX
regardless of the
heating time between

MAX DEFROST BY WEATHER

Factory default for this feature is disabled. When enabled Max
Defrost is always used if any of the following weather
conditions are reported via the Internet to the thermostat:
•
Rain (light, medium or heavy) and outdoor temperature
temperature is reported as less than 35°F
•
Sleet
•
Freezing rain
Note: This setting when enabled is always used regardless of
day, night or thermostat termination temperature setting in a
total communicating system.
®
iComfort Wi-Fi
Defrost termination is set at
MAX
OFF time > 30 minutes
YES
when
ambient temperature<35ºF
(See Note)
YES
defrost
Next defrost cycle
should run MAX
Figure 39. Automatic Max Defrost Rule
NOTE: Testing indicated
that the highest potential
for a weather event to
prevent fan operation due
to ice build up on the fan
NO
blade and orifice ring is
when the outdoor ambient
is below 35ºF and the unit
is OFF for more than 30
Last heating time between
defrost <= 50 minutes
Last two heating time
between defrost > 1 hr
YES
Next defrost cycle
should run 90ºF
termination
Example:
If the following conditions are true then the thermostat will
direct the outdoor unit control to operate the outdoor unit in
Max Defrost mode during this weather event.
•
Defrost termination temperature is set at 50°F, 70°F or
90°F in a full communicating system;
•
Any of the exampled weather conditions are forecast,
7-Day Programmable Communicating Thermostat
Page 33
minutes.
NO
NO
Next defrost cycle
should run the same
termination as
previous defrost
cycle