Installation and Setup
24
homexpert
tm
by Honeywell THR840DUK Digital Thermostat
25
Description of functions
Ot
Minimum boiler off time
: Check proper setting
for your system (see page 23).
Cr
Cycles per hour
: Check proper setting for your
system (see page 23).
Ot
Proportional band width
: If your heating system
is oversized for your home, you can compensate
by increasing the width of the control proportional
band up to 3°C.
tO
Temperature offset
: In some cases, the
thermostat must be installed in a location that
does not accurately control temperature for
optimum comfort in other rooms. You can set the
thermostat to compensate for this by adjusting
the offset.
uL
Maximum temperature
: When the
p
button
is pressed, the thermostat will not allow a target
temperature above the maximum you set.
LL
Minimum temperature
: When the
q
button is
pressed, the thermostat will not allow a target
temperature lower than the minimum you set.
ES
ECO default temperature
: This is the default
target temperature when the thermostat is in ECO
mode (see page 11).
HC
Heating/cooling options
: When set to 1, the
thermostat can control both heating and cooling
systems (see page 9).
OS
Frost protection temperature
: Minimum
temperature allowed when the thermostat is off
(see page 8).
EH
Electric heat
: Check proper setting for your
system (see page 23).
In case of difficulty
Thermostat screen
is blank
• Make sure two fresh AA alkaline batteries are properly installed (see
page 18).
Heating or cooling
system does not
respond
• Check thermostat batteries (see above).
• Make sure heating or cooling system has power. Check fuses and
circuit breakers and replace or reset as needed.
• Check wiring (pages 14-17) and system configuration (pages 20-24).
Desired temperature
cannot be maintained
• If above remedies cannot resolve the problem, the thermostat may
have to be moved. Make sure it is not installed near sources of hot or
cold air (radiators, windows, heating or cooling ducts).
• If this symbol flashes on the screen during normal operation, a fault has
occurred. Contact Honeywell Customer Care for assistance (see back
cover for contact information).
This Manual: http://www.manuallib.com/file/2598268
