Honeywell RTHL3550 - Manual or Auto Changeover

11
Function
Description
Press the s or t button to Setting
3 select your heating system
and fan operation
0 Gas or oil heat: Use this setting if you have a gas or oil
heating system (system controls fan operation).
1 Electric heat: Use this setting if you have an electric
heating system (thermostat controls fan operation).
5 select your heating system
and optimize its operation
5 Gas or oil furnace: Use this setting if you have a
standard gas or oil furnace that is less than 90%
efcient.
9 Electric furnace: Use this setting if you have any type
of electric heating system.
3 Hot water or high-efficiency furnace: Use this setting
if you have a hot water system or a gas furnace of
greater than 90% efciency.
1 Gas/oil steam or gravity system: Use this setting if
you have a steam or gravity heat system.
6 select your Stage 2 heating
system and optimize its
operation
5 Gas or oil furnace: Use this setting if you have a
standard gas or oil furnace that is less than 90%
efcient.
9 Electric furnace: Use this setting if you have any type
of electric heating system.
3 Heat pump, hot water or high-efficiency furnace:
Use this setting if you have a hot water system or a gas
furnace of greater than 90% efciency.
1 Gas/oil steam or gravity system: Use this setting if
you have a steam or gravity heat system.
12 select Manual or Auto
Changeover
0 Manual Changeover: (Heat/Off/Cool)
1 Automatic Changeover: (Heat/Off/Cool/Auto)
Automatically turns on heat or cool based on room
temperature.
CAUTION: To avoid possible compressor
damage, do not use Auto Changeover if the
outside temperature drops below 50 ºF (10 ºC).
NOTE: System maintains a minimum 3 ºF
difference between heat and cool settings.
14 select Fahrenheit or Celsius
temperature display
0 Fahrenheit temperature display (°F)
1 Celsius temperature display (°C)
27 select maximum heat
temperature setting
40 – 90 Maximum heat temperature setting (°F)
(4.5 to 31.5°C)
28 select minimum cool
temperature setting
50 – 99 Minimum cool temperature setting (°F)
(10.5 to 37°C)
About your new thermostat
Your new Honeywell thermostat has been designed to give you many years of
reliable service and easy-to-use, push-button climate control.
• Large, clear, backlit display is easy to read — even in the dark.
• Displays both room temperature and temperature setting.
• Removable battery holder for fast, easy replacement.
• Built-in compressor protection.