Honeywell T8611M

27 68-0076—1

Press and release to return to normal

operation.

CHECKING THE PROGRAM

TIMES AND TEMPERATURES

If desired, check all the stored settings

without affecting the permanent program.

Press and hold until the desired period shows

on the display. The start time and tempera-

ture setting will appear on the display.

Press and release to display the next day

time and temperature for that period.

Press and release to return to normal opera-

tion.

CHECKING THE CURRENT

TEMPERATURE SETTING

Press a single key to compare actual

room temperature to the setting at any

time.

Press and release. The display will show

the current temperature setting for several

seconds, then revert to the room tempera-

ture.

During recovery from energy savings, the

setting displayed will not match the pro-

grammed setting. This is because the ther-

mostat gradually changes the temperature

setting during recovery to provide maxi-

mum comfort combined with most effi-

cient use of the heating or cooling equip-

ment. Operation

The T8611M Thermostat provides automatic control of

multistage heat pump systems with up to three stages of

heat and up to two stages of cool. The first heat stage is the

heat pump and the last stage is electric, gas, or oil auxiliary

heat. T8611M provides automatic changeover from heat

to cool or cool to heat.

ADAPTIVE INTELLIGENT RECOVERY™

OPERATION

Adaptive Intelligent Recovery™ is the Honeywell trade-

mark for the way the T8611 controls the heating and

cooling equipment during recovery from an energy sav-

ings setting to a comfort setting. During recovery, the

control point changes gradually rather than jumping from

the energy savings setting to the comfort setting all at once.

This provides additional energy savings.

When Adaptive Intelligent Recovery™ is used in the

heating mode, the control point raises gradually, maximiz-

ing the use of the more economical heat pump to bring the

sensed temperature to the desired comfort setpoint. This

minimizes the use of the typically more expensive auxil-

iary heat.

In both heating and cooling, the thermostat monitors

recovery each day and adjusts the next day recovery start

time. This ensures that the building is at the desired

temperature at the programmed time, regardless of the

outdoor temperature. Recovery time varies depending on

the weather conditions and the building heating/cooling

system.

The advantages are:

• The comfort setting is achieved at the programmed

time and maintained regardless of weather condi-

tions; occupants come home and wake up to com-

fort.

• Drafts from low temperature discharge air are mini-

mized during occupied periods.

• The thermostat automatically uses the more eco-

nomical heat pump as the primary heat source dur-

ing heat mode recovery, avoiding the use of the

expensive auxiliary heat.

• Comfort and energy savings can be achieved in both

heating and cooling.

• Reduces heat pump compressor cycling, extending

equipment life.

Use of Outdoor Thermostats

Because Adaptive Intelligent Recovery™ calls for aux-

iliary heat only when it is truly needed, it eliminates the

need for outdoor thermostat(s). If an outdoor thermostat is

used with T8611 and it is set close to the balance point, the

recovery time from energy savings will be prolonged

because the outdoor thermostat will prevent operation of

PERIOD

DAY

RUN

PROGRAM

M2751

SET

HEAT

M2748

SET

FRI

NIGHT HEAT

M2749

SET

SAT

NIGHT HEAT

M2750

SET

FRI

EVENING

T8611M

OPERATING THE THERMOSTAT • OPERATION

PRESENT

SETTING