21 69-0333—6
ANTICIPATOR
SETTING LEVER
ANTICIPATOR
SCALEPLATE
M9616
Servicing The Thermostat

System on-length adjustment

NOTE: Not applicable on CT1503 Millivolt Heat
model.
If the thermostat seems to cycle the heating
system too fast or too slow, adjust the heating
system on-length by moving the anticipator
setting lever one indicator mark at a time (Fig. 6);
a higher setting will increase heating system on
length a lower setting will decrease heating
system on-length. Observe the heating system
operation after each adjustment.
The heat anticipator must be correctly set.
An incorrect setting can result in room tempera-
ture swings or burn out the anticipator, which
would void the thermostat warranty.
Fig. 6—Heat anticipator setting.
IMPORTANT:

Most hot water systems require

a setting of 1.3 times the valve current

rating.