Honeywell THR840DUK user manual Description of functions, Case of difficulty

Page 13

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.

LLMinimum 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).

HCHeating/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).

 

homexperttm by Honeywell THR840DUK Digital Thermostat

 

 

 

 

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).

 

 

 

 

 

24

25

Image 13
Contents THR840DUK Digital Thermostat Contents An explanation for householders What is a room thermostat?About your new thermostat Install and set up thermostatQuick reference 25.0 C On/off switch and frost protectionHeating or cooling control Energy-saving ECO mode Temperature control24.0 C Wall bracket installation System installationWiring diagrams Connect system wiringMake sure electrical power is off Basic boiler Combi boilerWiring diagrams Activate batteries and mount thermostat 35.0 CSystem test Installer setup functions Installer setupTo change installer settings Function Description Setting OptionsYour heating system Changes required Setting Options Customised settings for your systemYour cooling system Changes required Setting Options Case of difficulty Description of functionsDisposal and recycling Limited WarrantyDisposal and recycling Please retain these instructions for future referenceNeed Help?