Honeywell DT92E User Manual

User Guide
Y9420S Sundial RF
2
Pack 3
How to use:
ST9420C Wireless Enabled Programmer
DT92E Wireless Room Thermostat
CS92A Wireless Cylinder Thermostat
BDR91T Wireless Enabled Relay Box (if installed)
System Components
Energy Efficiency and the Environment
Home energy use is responsible for more than ¼ of the total UK carbon emissions
which contribute to climate change. Heating and hot water systems based on
boilers account for of this figure, so it is important to understand how your
controls can help to maximize energy efficiency while maintaining your comfort.
Your Programmer should be used in conjunction with appropriate temperature
controls. In order to save energy the following general points should be observed:
1. Ensure your system contains a room thermostat and a hot water thermostat,
and that both are set to appropriate temperature levels: typically 20°C for the
room temperature and between 50 - 60°C for the hot water temperature.
2.
Programme your heating and hot water to be off when you are not in the house. If
you are concerned about possible frost damage to any exposed pipe work, it is
advisable to fit a frost protection system – your installer can advise you about this.
3. Think about how you use your domestic hot water – if you have a storage
system, it is not necessary to have this switched on all the time, even when you
are in the house.
4. Consider the heat up times required for your central heating. Every home
responds differently when the heating is switched on. Adjust the start time so
that you are not cold when you get up in the morning. A shorter heat up time is
required for other heating periods.
5. In the evening, when the house is up to temperature, it is often possible to
switch off the heating up to an hour before you go to bed, without any noticeable
reduction in comfort.
This document is to be left with the user
and forms part of a Home Information Pack
This section is to be completed by the Installer
Honeywell Control Systems Ltd.
Arlington Business Park,
Bracknell
Berkshire
RG12 1EB
Technical Help Desk: 08457 678999
www.honeywelluk.com
50047645-008 A
© 2011 Honeywell International Inc.
PLEASE RESPECT YOUR ENVIRONMENT!
Take care to dispose of this product and any
packaging or literature in an appropriate way
WHAT IS A PROGRAMMER?
...an Explanation for Householders (as recommended by the Energy Savings Trust)
Programmers allow you to set ‘On’ and ‘Off’ time periods. Some models switch the central heating and
domestic hot water on and off at the same time, while others allow the domestic hot water and heating to
come on and go off at different times. Set the ‘On’ and ‘Off’ time periods to suit your own lifestyle. On some
programmers you must also set whether you want the heating and hot water to run continuously, run under
the chosen ‘On’ and ‘Off’ heating periods, or be permanently off. The time on the programmer must be
correct. Some types have to be adjusted in spring and autumn at the changes between Greenwich Mean
Time and British Summer Time. You may be able to temporarily adjust the
heating programme, for example, ‘Override’, ‘Advance’, or ‘Boost’. These
are explained in the manufacturer’s instructions. The heating will not work
if the room thermostat has switched the heating off. And, if you have a hot-
water cylinder, the water heating will not work if the cylinder thermostat
detects that the hot water has reached the correct temperature.
WHAT IS A ROOM THERMOSTAT?
...an explanation for Householders (as recommended by the Energy Savings Trust)
A room thermostat simply switches the heating system on and off as necessary. It works by sensing
the air temperature, switching on the heating when the air temperature falls below the thermostat
setting, and switching it off once this set temperature has been reached. Turning a room thermostat to
a higher setting will not make the room heat up any faster. How quickly the room heats up depends on
the design of the heating system, for example, the size of boiler and radiators. Neither does the setting
affect how quickly the room cools down. Turning a room thermostat to a lower setting will result in the
room being controlled at a lower temperature, and saves energy. The heating system will not work if
a time switch or programmer has switched it off. The way to set and use your room thermostat is to
find the lowest temperature setting that you are comfortable with, and then leave it alone to do its job.
The best way to do this is to set the room thermostat to a low temperature – say 18ºC – and then turn
it up by one degree each day until you are comfortable with the temperature. You won’t have to adjust
the thermostat further. Any adjustment above this setting will waste energy and cost you more money.
If your heating system is a boiler with radiators, there will usually be only one room thermostat to
control the whole house. But you can have different temperatures in individual rooms by installing
thermostatic radiator valves (TRVs) on individual radiators. If you don’t have TRVs, you should choose
a temperature that is reasonable for the whole house. If you do have TRVs, you can choose a slightly
higher setting to make sure that even the coldest room is comfortable, then prevent any overheating
in other rooms by adjusting the TRVs.
Room thermostats need a free flow of air to sense the temperature, so they must not be covered by
curtains or blocked by furniture. Nearby electric fires, televisions, wall or table lamps may prevent the
thermostat from working properly.
Location
ST9420C
DT92E
(typically in living room or hallway)
CS92A
(typically next to hot water tank, in bedroom)
BDR91T
(If installed, typically next to boiler)

Honeywell DT92E Specifications

General

Display	LCD
Power Supply	2 x AA batteries
Temperature Range	5°C to 35°C
Mounting	Wall-mounted
Switching Current	3 A
Switching Voltage	230 V AC
Backlight	No
Type	Digital Room Thermostat
Compatibility	Heating systems
Dimensions	92 x 92 x 27 mm
Weight	150g
Control Mode	TPI (Time Proportional Integral)

Summary

Understanding Heating System Components

What is a Programmer?

Explanation of how a programmer controls heating and hot water systems.

What is a Room Thermostat?

Explanation of how a room thermostat regulates heating.

Energy Efficiency and Environmental Considerations

System Component Identification and Configuration

Control Layouts for ST9420C, DT92E, and CS92A

Diagrams and labels for system components.

Configuration and Service Data Recording

Installer section for recording system setup and service history.

Control of Your System: Programmer Overview

General Description of System Components

Introduction to the ST9420C, DT92E, and BDR91T components.

Effective Programmer Usage

Guidance on setting and using the ST9420C programmer.

Control of Your System: Thermostat and Boiler Operation

Effective Room Thermostat Usage

Instructions for setting and using the DT92E room thermostat.

Boiler Control Methods

Methods for controlling the boiler via the system.

Understanding System Optimisation Features

Explanation of energy-saving optimisation settings like Optimum Start.

Getting Started with the ST9420C Programmer: Initial Setup

Step 1: Setting the Date and Time

Procedure to set the correct date and time on the ST9420C.

Getting Started with the ST9420C Programmer: Programme Activation

Step 2: Running a Built-in Programme

Activating the default pre-set heating programmes.

Programming the ST9420C: Setting Schedules

Overview of Built-in Programmes

Details of pre-defined heating and hot water schedules.

Creating Your Personal Programme

Guide to setting custom heating and hot water time periods.

Programming the ST9420C: Time Settings

Reviewing Programme Time Settings

How to check existing heating and hot water time settings.

Modifying the Hot Water Programme

Steps to change the ON/OFF times for hot water.

Programming the ST9420C: Daily Schedule Management

Copying and Programming Daily Schedules

Efficiently setting up programmes for multiple days.

Programming the ST9420C: Advanced Time Control

Modifying the Heating Programme

Steps to change the ON/OFF times for heating.

Disabling or Enabling Time Periods

Instructions for managing specific ON/OFF time slots.

Operating the ST9420C Programmer: Modes and Overrides

Selecting Operating Modes (Auto, Once, Off, Cont)

How to choose the system's operational mode.

Overriding Programme Settings

Temporarily changing heating/hot water status.

Operating the ST9420C Programmer: Special Functions

Using the Extra Hour Function

Adding extra hours to heating or hot water periods.

Setting the Holiday Function

Programming absence periods for energy saving.

Operating the ST9420C Programmer: Information Access

Accessing System Information via Enquiry Mode

Viewing current system temperatures and settings.

Fine Tuning the ST9420C Programmer: Settings

Changing Clock Display Format (12/24 Hour)

Switching between AM/PM and 24-hour clock displays.

Overview of Installer Parameters

List and description of advanced configurable settings.

Fine Tuning the ST9420C Programmer: Installer Mode Access

Entering and Navigating Installer Mode

Procedure to access and move through installer settings.

Fine Tuning the ST9420C Programmer: Optimisation Details

Detailed Explanation of Optimisation Features

Visuals and descriptions of Optimum Start, Stop, and Delayed Start.

Fine Tuning the ST9420C Programmer: Temperature and Service

Setting the Hot Water Temperature

Adjusting the desired hot water storage temperature.

Boiler Service Reminders and Safety

Service Countdown and Overdue Alerts

Notifications for upcoming and overdue boiler servicing.

Boiler Service Reminders and Safety: Shut-down

Automatic Boiler Shut-down for Overdue Service

System behaviour when boiler service is overdue.

Operating the DT92E Room Thermostat: Basic Use

Checking the Current Set Temperature

How to view the room temperature setpoint on the DT92E.

Adjusting the Room Temperature Setpoint

Procedure to change the desired room temperature.

Operating the DT92E Room Thermostat: Indicators and Modes

Switching the DT92E Off or to Standby

Turning the thermostat off or into standby mode.

Understanding DT92E Display Updates

Information on how the thermostat display communicates.

Interpreting Heating and Frost Protection Indicators

Meaning of the flame and frost symbols on the display.

DT92E Thermostat Operating Indicators

Low Battery Warning and Replacement

Identifying low battery and how to replace it.

RF Communication and Lockout Status Indicators

Understanding RF signal and lockout symbols.

DT92E Energy Saving ECO Feature: Activation and Use

Entering and Setting the ECO Energy Saving Period

Activating and configuring the energy-saving ECO mode.

ECO Mode Display and Temperature Adjustment

How ECO mode is shown and how to adjust the temperature within it.

DT92E Energy Saving ECO Feature: Deactivation

Exiting the DT92E ECO Mode

Procedure to deactivate the ECO energy-saving mode.

Fine Tuning the DT92E Thermostat: Parameter Adjustment

Changing DT92E Installer Parameters

Guide to modifying advanced settings for the DT92E.

Fine Tuning the DT92E Thermostat: Installer Mode Procedures

Entering and Exiting DT92E Installer Mode

Steps to access and leave the DT92E installer settings menu.

Selecting and Changing DT92E Parameters

How to navigate and modify specific DT92E settings.

Operating the CS92A Hot Water Thermostat: Overview

CS92A Basic Operation and Components

Overview of the CS92A sensor and transceiver.

CS92A Battery Replacement Procedure

Instructions for replacing batteries in the CS92A.

Interpreting CS92A Error Indicators

Understanding the meaning of CS92A's light signals.

Operating the BDR91T Relay Box: Functionality and Troubleshooting

BDR91T Controls Layout and Automatic Operation

Description of the BDR91T's controls and how it functions.

Temporary Manual Override and RF Communication Loss

Manual control and troubleshooting RF signal loss.

Frequently Asked Questions and Troubleshooting: Setup and Power Issues

Setting ST9420C Time and Handling Clock Changes

Troubleshooting date/time settings and automatic clock adjustments.

Recovering from Programming Errors and Power Failures

Guidance on navigating errors and system behaviour during power loss.

Frequently Asked Questions and Troubleshooting: Communication and Batteries

RF Communication Reliability and Troubleshooting

Addressing issues with wireless signal strength and loss.

Battery Replacement for CS92A and DT92E

Guidance on when and how to replace batteries in components.

Frequently Asked Questions and Troubleshooting: System Control and Issues

Overriding the Programmer from the DT92E Thermostat

Controlling the system from the room thermostat.

ST9420C Common Problems and Solutions

Detailed troubleshooting for ST9420C display and operational issues.

Frequently Asked Questions and Troubleshooting: Component Issues

Troubleshooting ST9420C Messages and Component Faults

Resolving specific error messages and component faults.

Frequently Asked Questions and Troubleshooting: RF and Sensor Faults

Troubleshooting RF Signal Loss and Sensor Faults

Diagnosing and fixing issues related to wireless communication and sensor errors.

Frequently Asked Questions and Troubleshooting: CS92A Sensor Issues

CS92A Sensor Fault and Connection Issues

Resolving specific sensor errors for the CS92A thermostat.

Installer Configuration and Service Data

ST9420C Configuration Parameters

Installer settings for the ST9420C programmer.

Recording System Configuration and Service History

Fields for documenting installer settings and service logs.