Gas Heat Control Mode - Lennox icomfort Wi-Fi Setup Manual

Gas Heat Control Mode

THERMOSTAT
DEMAND
SYSTEM
IDLE
506920−01 09/12
Differential
less than 2nd stage
NO
differential
?
YES
Starting firing rate
as determined by
variable capacity
algorithm (35 to
100%)
Differential
YES
less than 2nd stage
NO
differential
?
YES
Continue at
starting firing rate
T'stat
demand
NO
satisfied
?
YES
Figure 36. Variable Capacity Operation Flow Chart
Differential
less than 3rd stage less than 4th stage
NO
differential
?
YES
Increase firing rate Increase firing rate
to calculated 2nd to calculated 3rd
stage firing rate stage firing rate
T'stat
demand sat−
isfied in less than
isfied in less than
YES
5 minutes
?
NO
Differential
less than 4th stage
less than 3rd stage
NO
differential
?
YES
Firing rate
increased by increased by
5% every 5
minutes up to minutes up to
100% firing rate 100% firing rate
T'stat
demand
NO
satisfied
?
YES
Page 34
Increase firing
Differential
rate to 100%
until thermostat
NO
differential
demand is
?
satisfied
YES
T'stat
demand sat−
5 minutes
?
NO
Differential
NO
differential
?
YES
Firing rate
5% every 5
T'stat
demand
NO
satisfied
?
YES