In Case Of Difficulty - Honeywell thr840duk User Manual

Installation and Setup
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.
This Manual: http://www.manuallib.com/file/2598268
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).
24

In case of difficulty

Thermostat screen • Make sure two fresh AA alkaline batteries are properly installed (see
is blank page 18).
Heating or cooling • Check thermostat batteries (see above).
system does not
• Make sure heating or cooling system has power. Check fuses and
respond
circuit breakers and replace or reset as needed.
• Check wiring (pages 14-17) and system configuration (pages 20-24).
Desired temperature • If above remedies cannot resolve the problem, the thermostat may
cannot be maintained 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).
homexpert by Honeywell THR840DUK Digital Thermostat
tm
25