tekmar 557 Thermostat Installation - Manual (Page 33)

© 2014 557_D - 09/14
33 of 52 A Watts Water Technologies Company
Heating Operation Section A
Sequence of Operation
Set Heat Temperature ----------------------------------------------- -----------------------------------------------
The 557 can operate radiant floor heating, heat pump stage 1 and stage 2, and a backup
heat source to provide heating in different combinations depending on the outdoor air
temperature. The illustration below shows when each of the available heating units are
available. The “Heat On” symbol is shown on the display when the thermostat is heating. If not
operating a heat pump, the first and second stage of heat (W1 and W2) are allowed to turn
on below the Warm Weather Shut Down to maintain the Set Heat Room temperature.
No heating Air heating only All allowed No backup heat
Colder
Outdoor
Temperature
Set Heat
Room
Room
Warmer
Room
Colder
Warm Weather
Shut Down
Default = 70°F
Radiant Floor
Warm Weather
Shut Down
Default = 60°F
Balance
Point
Default = Off
Lockout
Default = 60°F
Heat Pump - Heating Mode
No heat pump
Y2 off
Y1 off
Y2 on
Y1 on
W2 off
Y2 off
Y1 off
W1 off
W2 on
Y2 on
Y1 on
W1 on
Y2 off
Y1 off
W1 off
Y2 on
Y1 on
W1 on
W2 off
W1 off
W2 on
W1 on
Air Temperature Heating --------------------------------------------- ---------------------------------------------
When using only a room temperature sensor, the thermostat operates the heating
system to maintain the Set Heat Room temperature.
Floor Heating -------------------------------------------------------- --------------------------------------------------------
When using both a room and a floor temperature sensor, the thermostat always maintains
the Floor Minimum temperature, even when the air temperature is satisfied. When the
air temperature is below the Set Heat Room temperature, the thermostat operates the
heating system to maintain the Set Heat Room temperature. The floor is never heated
above the Floor Maximum setting in order to protect the floor covering.
Suggested Floor Maximum settings are 90°F (32°C) for tile, stone, or concrete floors
and 85°F (29°C) for wood floors.