Hamworthy Dorchester DR-FC 80-95 Installation guide

Brand: Hamworthy

Model: Dorchester DR-FC 80-95

Category: Water heaters & boilers

Type: Installation guide

DORCHESTER MODELS: DR-FC 80, 95

Condensing, Closed Combustion, Direct Gas Fired Hot Water Storage Heaters

with Automatic Ignition for

Domestic Hot Water Installations

NOTE: THESE INSTRUCTIONS MUST BE READ AND UNDERSTOOD BEFORE

INSTALLING, COMMISSIONING, OPERATING OR SERVICING EQUIPMENT.

THIS WATER HEATER IS FOR USE ON GROUP H NATURAL GAS (2ND FAMILY) I2H OR

LPG (3RD FAMILY) I3P. PLEASE ENSURE RELEVANT INFORMATION REQUIRED WITHIN

DOCUMENT IS FOUND RELATING TO SPECIFIC GAS TO BE FIRED BEFORE FIRING

HEATER.

THIS WATER HEATER COMPLIES WITH ALL RELEVANT EUROPEAN DIRECTIVES.

PUBLICATION NO. 500001154

ISSUE ‘A’

FEBRUARY 2006

DORCHESTER

DR-FC 80 to DR-FC 95

HOT WATER

STORAGE HEATERS

Installation, Commissioning

and Maintenance Instructions

Page is loading ...

Instruction Manual DR-FC 3

gis

Table of contents

Table of contents - - - - - - - - - - - - - - - - - - - - - - - - - 3

1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - 7

1.1 About the water heater - - - - - - - - - - - - - - - - - - - - - - - - - - - 7

1.2 What to do if you smell gas- - - - - - - - - - - - - - - - - - - - - - - - - 7

1.3 Regulations and documents - - - - - - - - - - - - - - - - - - - - - - - - 7

1.4 Target groups - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8

1.5 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

1.6 Forms of notation - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

1.7 Overview of this document - - - - - - - - - - - - - - - - - - - - - - - - 10

2 Functioning of the water heater - - - - - - - - - - - - - - - - 11

2.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11

2.2 Functional description of the water heater - - - - - - - - - - - - - - - - 12

2.3 The water heater’s heating cycle - - - - - - - - - - - - - - - - - - - - - 13

2.4 Protection for the water heater - - - - - - - - - - - - - - - - - - - - - - 13

2.4.1 Water temperature protection - - - - - - - - - - - - - - - - - 14

2.4.2 Gas control - - - - - - - - - - - - - - - - - - - - - - - - - - 14

2.4.3 Fan - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 14

2.4.4 Pressure switch - - - - - - - - - - - - - - - - - - - - - - - - 14

2.4.5 Flame probe - - - - - - - - - - - - - - - - - - - - - - - - - 15

2.5 Safety of the installation - - - - - - - - - - - - - - - - - - - - - - - - - 15

2.5.1 Unvented installation - - - - - - - - - - - - - - - - - - - - - 15

2.5.2 Vented installation- - - - - - - - - - - - - - - - - - - - - - - 15

2.5.3 T&P valve - - - - - - - - - - - - - - - - - - - - - - - - - - - 15

2.6 Options - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 15

2.6.1 LPG- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 15

2.6.2 Unvented Supply - - - - - - - - - - - - - - - - - - - - - - - 15

2.6.3 Top to Bottom Circulation - - - - - - - - - - - - - - - - - - - 15

3 Installation - - - - - - - - - - - - - - - - - - - - - - - - - - - 17

3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17

3.2 Packaging - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17

3.3 Environmental conditions- - - - - - - - - - - - - - - - - - - - - - - - - 17

3.3.1 Humidity and ambient temperature- - - - - - - - - - - - - - - 18

3.3.2 Maximum floor loading - - - - - - - - - - - - - - - - - - - - 18

3.3.3 Working clearances - - - - - - - - - - - - - - - - - - - - - - 19

3.4 Technical specifications - - - - - - - - - - - - - - - - - - - - - - - - - 20

3.5 Installation diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - 22

3.6 Water connections, Unvented - - - - - - - - - - - - - - - - - - - - - - 24

3.6.1 Cold water side - - - - - - - - - - - - - - - - - - - - - - - - 24

3.6.2 Top to bottom recirculating pump - - - - - - - - - - - - - - - 24

3.6.3 Hot water side- - - - - - - - - - - - - - - - - - - - - - - - - 24

3.6.4 Circulation pipe - - - - - - - - - - - - - - - - - - - - - - - - 24

3.6.5 Condensation drainage - - - - - - - - - - - - - - - - - - - - 24

gis

4Instruction Manual DR-FC

gis

3.7 Water connections, Vented - - - - - - - - - - - - - - - - - - - - - - - - 25

3.7.1 Cold water side- - - - - - - - - - - - - - - - - - - - - - - - - 25

3.7.2 Top to bottom recirculating pump - - - - - - - - - - - - - - - - 25

3.7.3 Hot water side - - - - - - - - - - - - - - - - - - - - - - - - - 25

3.7.4 Circulation pipe- - - - - - - - - - - - - - - - - - - - - - - - - 25

3.7.5 Condensation drainage - - - - - - - - - - - - - - - - - - - - - 25

3.8 Gas connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 25

3.9 Air supply and flue gas discharge - - - - - - - - - - - - - - - - - - - - - 26

3.9.1 Concentric wall flue terminal C13 - - - - - - - - - - - - - - - - 27

3.9.2 Concentric roof flue terminal C33 - - - - - - - - - - - - - - - - 28

3.10 Electrical connections - - - - - - - - - - - - - - - - - - - - - - - - - - - 29

3.10.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 29

3.10.2 Preparation- - - - - - - - - - - - - - - - - - - - - - - - - - - 29

3.10.3 Mains power - - - - - - - - - - - - - - - - - - - - - - - - - - 30

3.10.4 Isolating transformer - - - - - - - - - - - - - - - - - - - - - - 31

3.10.5 program-controlled pump - - - - - - - - - - - - - - - - - - - - 31

3.10.6 Extra ON mode switch (’Tank ON’) - - - - - - - - - - - - - - - 31

3.10.7 Connecting extra error signal (’Alarm OUT’) - - - - - - - - - - - 31

3.11 Checking the supply pressure and burner pressure - - - - - - - - - - - - 32

3.12 Conversion to a different gas category - - - - - - - - - - - - - - - - - - - 35

3.12.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 35

4 Filling and draining - - - - - - - - - - - - - - - - - - - - - - - 37

4.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 37

4.2 Filling the water heater - - - - - - - - - - - - - - - - - - - - - - - - - - 37

4.2.1 Filling unvented installations - - - - - - - - - - - - - - - - - - 37

4.2.2 Filling vented installations- - - - - - - - - - - - - - - - - - - - 37

4.3 Draining the water heater - - - - - - - - - - - - - - - - - - - - - - - - - 39

4.3.1 Draining unvented installations - - - - - - - - - - - - - - - - - 39

4.3.2 Draining vented installations - - - - - - - - - - - - - - - - - - 39

5 The control panel - - - - - - - - - - - - - - - - - - - - - - - - 41

5.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 41

5.2 Overview - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 41

5.3 Explanation of the icons - - - - - - - - - - - - - - - - - - - - - - - - - - 42

5.4 Control panel ON/OFF switch - - - - - - - - - - - - - - - - - - - - - - - 42

5.5 Navigation buttons - - - - - - - - - - - - - - - - - - - - - - - - - - - - 42

5.6 PC connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 43

6 Status of the water heater - - - - - - - - - - - - - - - - - - - 45

6.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 45

6.2 Operating modes - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 45

6.3 Error conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 46

6.4 Service condition - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47

6.5 Anode protection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47

7 Starting up and shutting down - - - - - - - - - - - - - - - - - 49

7.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49

7.2 Starting up - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49

7.3 Shutting down- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 50

7.3.1 Shut the water heater down for a brief period (’OFF mode’) - - - 50

7.3.2 Isolate the water heater from the power supply - - - - - - - - - 50

7.3.3 Shut the water heater down for a longer period - - - - - - - - - 51

Instruction Manual DR-FC 5

gis

7.4 The water heater’s heating cycle - - - - - - - - - - - - - - - - - - - - - 51

8 Main menu - - - - - - - - - - - - - - - - - - - - - - - - - - - 53

8.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 53

8.2 Notational convention for menu-related instructions - - - - - - - - - - - - 53

8.3 Switching into ’ON mode’- - - - - - - - - - - - - - - - - - - - - - - - - 54

8.4 Setting the water temperature - - - - - - - - - - - - - - - - - - - - - - 54

8.4.1 Setting the water temperature via SETPOINT menu - - - - - - 54

8.4.2 Setting water temperature during ON mode - - - - - - - - - - 54

8.5 Week program - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 55

8.5.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 55

8.5.2 Starting up and shutting down the week program- - - - - - - - 55

8.5.3 Changing the water heater’s standard week program- - - - - - 55

8.5.4 Adding times to a week program - - - - - - - - - - - - - - - - 57

8.5.5 Deleting times from a week program - - - - - - - - - - - - - - 58

8.6 Extra period - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 60

8.6.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 60

8.6.2 Programming an extra period - - - - - - - - - - - - - - - - - 60

8.7 Settings - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 61

8.7.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 61

8.7.2 Setting menu language - - - - - - - - - - - - - - - - - - - - 61

8.7.3 Setting day and time- - - - - - - - - - - - - - - - - - - - - - 62

8.7.4 Displaying water heater specifications - - - - - - - - - - - - - 62

9 Service program - - - - - - - - - - - - - - - - - - - - - - - - 65

9.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 65

9.2 Setting the hysteresis - - - - - - - - - - - - - - - - - - - - - - - - - - 65

9.3 Displaying the error history - - - - - - - - - - - - - - - - - - - - - - - - 65

9.4 Displaying the water heater history - - - - - - - - - - - - - - - - - - - - 66

9.5 Display the selected water heater - - - - - - - - - - - - - - - - - - - - 66

9.6 Setting the pump on/off - - - - - - - - - - - - - - - - - - - - - - - - - 66

9.7 Setting the service interval - - - - - - - - - - - - - - - - - - - - - - - - 66

9.8 Setting the display contrast- - - - - - - - - - - - - - - - - - - - - - - - 67

9.9 Setting the backlight time- - - - - - - - - - - - - - - - - - - - - - - - - 67

9.10 Setting the display scroll speed- - - - - - - - - - - - - - - - - - - - - - 67

10 Troubleshooting - - - - - - - - - - - - - - - - - - - - - - - - 69

10.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 69

10.2 Troubleshooting table for general errors - - - - - - - - - - - - - - - - - 70

10.3 Troubleshooting table for anode protection - - - - - - - - - - - - - - - - 73

10.4 Troubleshooting table for displayed errors - - - - - - - - - - - - - - - - 74

11 Maintenance frequency - - - - - - - - - - - - - - - - - - - - 85

11.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 85

11.2 Determining service interval - - - - - - - - - - - - - - - - - - - - - - - 85

12 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 87

12.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 87

12.2 Preparation for maintenance - - - - - - - - - - - - - - - - - - - - - - - 87

12.3 Water-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - 89

12.3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 89

12.3.2 Checking the anodes - - - - - - - - - - - - - - - - - - - - - 89

12.3.3 Descaling and cleaning the heater - - - - - - - - - - - - - - - 89

12.3.4 Cleaning condensation water discharge - - - - - - - - - - - - 89

6Instruction Manual DR-FC

gis

12.4 Gas-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 90

12.4.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 90

12.4.2 Cleaning the burner - - - - - - - - - - - - - - - - - - - - - - 90

12.4.3 Cleaning the orifice - - - - - - - - - - - - - - - - - - - - - - - 90

12.4.4 Cleaning heat exchanger - - - - - - - - - - - - - - - - - - - - 90

12.5 Finalising maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 90

A Appendices - - - - - - - - - - - - - - - - - - - - - - - - - - - 91

A.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 91

A.2 Electrical diagram DR-FC - - - - - - - - - - - - - - - - - - - - - - - - - 92

A.3 Week program card - - - - - - - - - - - - - - - - - - - - - - - - - - - - 93

About the water heater

Instruction Manual DR-FC 7

gis

1 Introduction

1.1 About the water

heater

This manual describes how to install, service and use the DR-FC water heater.

The DR-FC water heater is a condensing room-sealed water heater with a fan

in the air intake. A concentric chimney connector is fitted standard to the water

heater. Alternatively, the water heater can be connected using a parallel system.

Installation types possible with this water heater are C13, C33, and C53. The

information in this manual is applicable to types: DR-FC 80 and DR-FC 95.

The manner of construction and features of the water heater are in conformance

with the European standard for gas-fired storage water heaters for the

production of domestic hot water (EN 89). The water heaters are compliant with

the European Directive for Gas Water heaters, and have the right to bear the

CE mark.

Warning

Read this manual carefully before starting up the water heater. Failure to

read the manual and to follow the printed instructions may lead to personal

injury and damage to the water heater.

1.2 What to do if you

smell gas Warning

Whenever there is a smell of gas:

No naked flames! No smoking!

Avoid causing sparks! Do not use any electrical equipment or switch, i.e. no

telephones, plugs or bells!

Shut off the mains gas supply!

Open windows and doors!

Warn occupants and leave the building!

After leaving the building, alert the gas distribution company or installer.

1.3 Regulations and

documents

Gas Safety Installations and Use Regulations 1998, (As amended). It is law

that all gas appliances are installed by competent persons, in accordance with

the above regulations. Failure to install appliances correctly could lead to

prosecution. It is in your own interest, and that of safety, to ensure that this law

is complied with.

The installation of the boiler MUST be in accordance with the relevant

requirements of the Gas Safety Regulations, Building Regulations, IEE

Regulations and the Water Supply (water fittings) Regulations.

The installation should also be in accordance with any relevant requirements of

the HSE, local gas region and local authority and the relevant recommendations

of the following documents:

British Standards

•BS 6891: Specification for installation of low pressure gas pipework of up to

28 mm (R1) in domestic premises (2nd family gas). For larger installations

see IGE/UP/2 below.

0063

gis

Introduction

8Instruction Manual DR-FC

1gis

•BS 6798: Specification for installation of gas-fired boilers of rated input not

exceeding 70 kW net.

•BS 6644: Specification for installation of gas-fired hot water boilers of rated

inputs between 60 kW and 2 MW (2nd and 3rd family gases).

•BS 6700: Specification for design, installation, testing and maintenance of

services supplying water for domestic use within buildings and their

curtilages.

•BS EN 806-2: Specification for installations inside buildings conveying water

for human consumption. Part 2: Design.

•BS 5546: Specification for installation of hot water supplies for domestic

purposes, using gas-fired appliances of rated input not exceeding 70 kW.

•BS 5440: Installation and maintenance of flues and ventilation for gas

appliances of rated input not exceeding 70 kW net (1st, 2nd and 3rd family

gases). Part 1: Flues. Part 2: Ventilation.

Institute of Gas Engineers and Managers Publications

• IGE/UP/1 Soundness testing and purging of industrial and commercial gas

installations.

• IGE/UP/1A Soundness testing and direct purging of small low pressure

industrial and commercial natural gas installations.

• IGE/UP/2 Gas installation pipework, boosters and compressors on industrial

and commercial premises.

• IGE/UP/10 Installation of gas appliances in industrial and commercial

premises. Part 1: flued appliances.

CIBSE Publications:- "CIBSE Guide"

Section B4 : Water Service Systems.

1.4 Target groups The three target groups for this manual are:

• (end) users;

•installers;

• service and maintenance engineers

Symbols on each page indicate the target groups for whom the information is

intended. See Table 1.1.

Table 1.1 Target group symbols

Symbol Target group

g(End) user

iInstaller

sService and maintenance engineer

Maintenance

Instruction Manual DR-FC 9

gis

1.5 Maintenance A service should be carried out at least once a year, both on the water side and

on the gas side. Maintenance frequency depends, among other things, on the

water quality, the average burning time per day and the set water temperature.

nRemark

To determine the correct maintenance frequency, it is recommended to

arrange for the service and maintenance engineer to check the water heater

on both the water and gas side, three months after installation. Based on this

check, the best maintenance frequency can be determined.

nRemark

Regular maintenance extends the service life of the water heater.

Both the end user and the service and maintenance engineer are responsible

for regular maintenance. They will need to establish clear agreements on this.

nRemark

If the water heater is not regularly maintained, the warranty will become void.

1.6 Forms of notation The following notation is used in this manual:

nRemark

Important information

cNote

Ignoring this information can lead to the water heater being damaged.

Warning

Failure to carefully read this information may lead to danger of personal

injury, and serious damage to the water heater.

Introduction

10 Instruction Manual DR-FC

1gis

1.7 Overview of this

document

Table 1.2 provides an overview of the contents of this document.

Table 1.2 Contents of document

Chapter Target groups Description

2 Functioning of the water

heater gis This chapter describes how the water heater functions.

3Installation is This chapter describes the installation activity to be completed

before you actually start up the water heater. Instructions are

also provided for the installation and/or service and

maintenance engineer on converting the water heater to other

types of gas.

4 Filling and draining gis This chapter describes how to fill and drain the water heater.

5 The control panel gis This chapter describes the general control of the water heater

using the display.

6 Status of the water heater gis This chapter describes the status (mode or condition) that the

water heater may have, and possible actions to take.

7 Starting up and shutting

down gis This chapter describes how to start up the water heater, and

how to shut it down for a brief or long period of time. The

general heating cycle of the water heater is also described.

8 Main menu gis Describes the main menu of the display. This is the actual

menu for the user, however the installer and service and

maintenance engineers will also need to use this menu.

9 Service program is Describes the service menu. It is mainly intended for the

installer and service and maintenance engineers. End users

may also refer to this chapter for additional information about

the water heater.

10 Troubleshooting gis This chapter is mainly intended for the installer and the service

and maintenance engineer. It describes water heater errors.

These errors are indicated on the display. A troubleshooting

table of possible causes and solutions is provided. End users

may also refer to this chapter for additional information about

the water heater.

11 Maintenance frequency gs This chapter describes how to determine the optimum

frequency at which to carry out maintenance. Both the end

user and the service and maintenance engineer are

responsible for regular maintenance. They need to reach clear

agreement on this.

nRemark

If the water heater is not regularly maintained, the warranty

will become void.

12 Maintenance sThis chapter sets out the maintenance tasks to be carried out

during a service.

Introduction

Instruction Manual DR-FC 11

gis

2 Functioning of the

water heater

2.1 Introduction Topics covered in this chapter:

•Functional description of the water heater;

•The water heater’s heating cycle;

•Protection for the water heater;

•Safety of the installation.

gis

Functioning of the water heater

12 Instruction Manual DR-FC

2gis

2.2 Functional

description of the

water heater

Figure 2.1 shows a cut-away view of the water heater.

In this water heater, the cold water enters the bottom of the tank via the cold

water inlet (18). The tap water, heated by the combustion chamber (11) and

heat exchanger (29), leaves the tank through the hot water outlet (3). Once the

water heater is completely filled with water, it remains constantly under water

supply pressure. As hot water is drawn from the water heater, cold water is

immediately added.

The water heater is equipped with a gas/air premix burner (15). The air is drawn

in through the fan (12). The gas is added via the gas control (26) on the intake

side of the fan. The gas/air mixture is then blown into the burner. Thanks to the

modulated supply of gas and air, the optimum gas/air mixture is always

achieved.

Legend

(1) top cover

(2) mains choke

(3) hot water outlet

(4) control panel

(5) EMC filter

(6) frequency controller

(7) temperature sensor T1

(8) control panel

(9) potentiostat

(10) electrical connection block

(11) combustion chamber

(12) fan

(13) hot surface igniter

(14) flame probe

(15) burner

(16) inspection and cleaning

opening

(17) drain valve

(18) cold water inlet

(19) temperature sensor T2

(20) insulation layer

(21) pallet

(22) automatic air bleed

(23) circulation pump

(24) air supply hose

(25) pressure switch

(26) gas control

(27) anode

(28) tank

(29) heat exchanger

(30) chimney pipe

(31) siphon

IMD-0399

Figure 2.1 Cut-away view of the water heater

(1)

(3)

(10)

(8)

(25)

(4)

(7)

(11) (27)

(28)

(29)

(16)

(19)

(18)

(17)

(26)

(15)

(12)

(13)

(14) (30)

(31)

(20)

(21)

(6)

(9)

(23)

(24)

(2)

(5)

(22)

The water heater’s heating cycle

Instruction Manual DR-FC 13

gis

Through the special design of the heat exchanger (29), the flue gases are first

led downwards via the combustion chamber, then upwards again via the heat

exchanger, then once more downwards beside the water in the tank. In this

process, the flue gases gradually become cooler. Because the cooled flue

gases flow alongside the cold water lower down in the tank, they start to

condense. This condensation causes latent heat energy to be released, which

is transferred to the cooler water, and thereby increases the performance of the

unit. The condensate yielded by this process is discharged via the siphon (31).

The insulation layer (20) prevents heat loss. The inside of the tank is enamelled

to protect against corrosion. The two electrical low-maintenance anodes (27)

provide additional protection against corrosion.

For use during maintenance, the water heater has a inspection and cleaning

opening (16).

2.3 The water heater’s

heating cycle

The entire water heater is controlled (and monitored) by the control panel (4).

The temperature sensor T1 (7) (in the top of the tank (28)) and the temperature

sensor T2 (19) (lower down in the tank) measure the water temperature. The

continuous pump, standard in these water heaters, prevents excessive water

temperature differences within the water heater. The temperatures observed by

T1 and T2 are signaled to the control panel. Based on these two observations,

the control panel calculates a net water temperature: Tnet. The value of Tnet lies

between the temperatures measured at the top and bottom of the tank. As soon

as Tnet falls below the set water temperature (Tset), the control panel registers a

‘heat demand’. The gas control (26) is opened, and the gas is mixed with air.

This mixture is ignited by the hot surface igniter (13) and the water becomes

heated. As soon as Tnet rises above Tset, the heat demand ends, and the control

panel stops the heating cycle.

Both when registering and ending the heat demand, the control panel assumes

a certain margin. We refer to this margin as the hysteresis (see paragraph

’9.2 Setting the hysteresis’).

2.4 Protection for the

water heater

The control panel monitors the water temperature and ensures safe

combustion. This is achieved by:

•the Water temperature protection;

•the Gas control;

•the Fan;

•the Pressure switch;

•the Flame probe.

Functioning of the water heater

14 Instruction Manual DR-FC

2gis

2.4.1 Water temperature protection

Using temperature sensor T1 (7) and temperature sensor T2 (19), the control

panel monitors three temperatures which are important for safety. Table 2.1

explains the functioning of the temperature sensors.

2.4.2 Gas control

The control panel opens the gas control so that gas can be supplied to the

burner. As a safety measure, the gas control has two valves. Both valves shut

off the gas supply.

2.4.3 Fan

The fan, controlled by the frequency controller (6), provides an optimum air

supply when there is a heat demand. A safety aspect is that the fan ensures that

any gases present in the combustion chamber get removed, both before and

after combustion. We refer to this as pre- and post-purge.

2.4.4 Pressure switch

The pressure switch ensures the discharge of flue gases and the supply of

incoming air during the pre-purge and normal running of the water heater. The

standard position of the pressure switch is open. When sufficient pressure

differential is reached, the pressure switch closes. However, in the event of a

fault, the pressure switch will be tripped open, and the heating cycle will be

interrupted.

Table 2.2 shows the trip point per water heater.

nRemark

The trip point of the pressure switch is not adjustable.

Table 2.1 Temperature protection

Protection Description

Against frost

(T1 < 5°C or T2 < 5°C)

The frost protection cuts in. The water is heated to 20°C.

For maximum water temperature

(T1 > 85°C or T2 > 85°C)

The high-limit safeguard serves to prevent overheating and/or excessive

formation of scale in the water heater. Should the high-limit safeguard be

activated, the heating is halted. This causes the water in the tank to cool down.

Once the water has cooled sufficiently (T1 < 78 °C), the control panel resets

the water heater.

For extra safety

(T1 > 93°C or T2 > 93°C)

A lockout error of the water heater controller takes place. The controller must

be manually reset before the water heater can resume operation (see

paragraph ’6.3 Error conditions’). The reset may only be performed once T1 <

78°C.

Table 2.2 Pressure switch trip points

Water

heater

Pressure differential [Pa]

Closing Opening

DR-FC

> 395 < 365

DR-FC

> 525 < 495

Safety of the installation

Instruction Manual DR-FC 15

gis

2.4.5 Flame probe

To ensure that no gas can flow when there is no combustion, an flame probe

has been fitted. The control panel uses this rod for flame detection, by means

of ionisation detection. The control panel cuts in, the instant it detects that there

is a gas flow but no flame.

2.5 Safety of the instal-

lation

2.5.1 Unvented installation

With an unvented installation, a expansion valve and expansion vessel prevent

excessive pressure in the tank. This prevents damage being caused to the

enamelled coating (in the water heater) or to the heater. A non-return valve

prevents excessive pressure in the water supply system. This valve also

prevents water from flowing backwards from the tank into the cold water supply

system. The pressure reducing valve protects the installation against an

excessively high water supply pressure. These components are fitted to the cold

water pipe. See paragraph ’3.6.1 Cold water side’.

2.5.2 Vented installation

With a vented installation, excess pressure is taken up by the open water tank.

The level of the water tank determines the maximum working pressure in the

heater, which may not exceed 8 bar. The installation must also be fitted with an

open vent from the hot water pipe, which discharges into a tundish. See

paragraph ’3.6.3 Hot water side’.

2.5.3 T&P valve

A T&P valve is mandatory in an ‘unvented’ installation.

A T&P valve monitors the pressure in the heater, and the water temperature at

the top of the heater. If the pressure in the heater becomes excessive (>7 bar)

or the water temperature is too high (>97°C), the valve will open. The hot water

will immediately flow out of the heater. Because the water heater is under water

supply pressure, cold water will automatically flow into the heater. The valve

remains open until the unsafe situation has been averted. A connecting point for

a T&P valve is standard on the water heater. See paragraph ’3.6.3 Hot water

side’.

2.6 Options The heaters can be supplied with the following additional variations, either

ready fitted or for site fitting:

2.6.1 LPG

The heaters can be supplied adjusted for use on propane or butane, see section

3.12. It is most important that the heater is correctly adjusted for the gas to be

fired.

2.6.2 Unvented Supply

The heaters can be supplied with a purpose designed and sized unvented kit

comprising pressure reducing valve, non-return valve, expansion vessel,

expansion relief valve and pressure/temperature relief valve, to enable the

heater to be coupled directly to the mains water. For details see 2.5.1, 2.5.3 and

3.6.

2.6.3 Top to Bottom Circulation

In order to give enhanced temperature control to aid compliance with the HSE

guidance and the DHss Code of Practice for 'The Control of Legionellae in

Health Care Premises', a pump circulation kit can be supplied comprising 230

volt single phase pump, non-return valve, pipe work and sufficient fittings to

contact between the hot water flow and the bottom connection. For details see

section 3.5 of this manual.

Functioning of the water heater

16 Instruction Manual DR-FC

2gis

Introduction

Instruction Manual DR-FC 17

3 Installation

Warning

The installation should be carried out by an approved installer in compliance

with the general and local regulations imposed by the gas, water and power

supply companies and the fire service.

The water heater may only be installed in a room which complies with the

requirements stated in national and local ventilation regulations.

Refer also to paragraph ’1.3 Regulations and documents’.

3.1 Introduction This chapter describes the installation activities to be carried out before the

water heater may be started up, namely:

•Packaging;

•Environmental conditions;

•Technical specifications;

•Water connections, Unvented;

•Water connections, Vented;

•Gas connection;

•Air supply and flue gas discharge;

•Electrical connections;

•Checking the supply pressure and burner pressure;

•Conversion to a different gas category.

nRemark

Starting up the water heater is described in chapter ’7 Starting up and

shutting down’.

3.2 Packaging To avoid damaging the water heater, remove the packaging carefully.

We recommend unpacking the water heater at or near its intended location.

cNote

The water heater may only be manoeuvred in an upright position. Take care

that the water heater is not damaged after unpacking.

3.3 Environmental

conditions The DR-FC water heater is a room-sealed water heater. Installation types

possible with this water heater are C13, C33, and C53. This makes it possible

to install the water heater in either a closed or an open boiler room.

Installation

18 Instruction Manual DR-FC

3is

3.3.1 Humidity and ambient temperature

The boiler room must be frost-free, or be protected against frost. Table 3.1

shows the environmental conditions that must be adhered to, for correct

functioning of the electronics present in the water heater to be guaranteed.

3.3.2 Maximum floor loading

In connection with the water heater’s weight, take account of the maximum floor

loading, see Ta b le 3. 2 .

Table 3.1 Humidity and ambient temperature specifications

Humidity and ambient temperature

Humidity max. 93% RH at +25°C

Ambient temperature Functional: 0 ≤ t ≤ 50°C

Table 3.2 Weight specifications related to maximum floor loading

Weight of the water heater filled with water

DR-FC 80, DR-FC 95 893 kg

Environmental conditions

Instruction Manual DR-FC 19

3.3.3 Working clearances

For access to the water heater it is recommended that the following

clearances are observed (see Figure 3.1):

• AA: around the water heater’s control column and cleaning openings: 100

cm.

• BB: around the water heater itself: 50 cm.

nRemark

When installing the water heater, be aware that any leakage from the tank

and/or connections can cause damage to the immediate environment or

floors below the level of the boiler room. If this is the case, then the water

heater should be installed above a wastewater drain or in a suitable metal

leak tray.

The leak tray must have an appropriate wastewater drain and must be at

least 5 cm deep with a length and width at least 5 cm greater than the

diameter of the water heater.

Figure 3.1 Working clearances

IMD-0227

Installation

20 Instruction Manual DR-FC

3is

3.4 Technical specifica-

tions

The water heater is supplied without accessories. Check the dimensions and

other specifications for the accessories to be used, based on Figure 3.2 and

tables Tab le 3 .3 through Ta ble 3 . 6.

Figure 3.2 Plan and elevation of the water heater

IMD-0400

Table 3.3 Dimensions

Dimensi

Description Unit DR-FC 80 DR-FC 95

A Total height mm 2100 2100

D Water heater diameter mm 845 845

E Depth mm 1000 1000

FWidth mm 900 900

GDiameter of air supply/flue gas discharge mm 130/200 130/200

K Height of gas connection mm 1845 1845

M Height of cold water supply connection mm 225 225

Technical specifications

Instruction Manual DR-FC 21

N Height of hot water outlet connection mm 2050 2050

P Height of cleaning and inspection opening mm 290 290

R Height of drain valve mm 225 225

S Height of T&P valve mm 1415 1415

W Height of condensation drainage connection mm 260 260

X Height of air supply connection mm 1830 1830

1 Cold water supply connection - R 11/2

2 Hot water outlet connection - R 11/2

3 Gas control connection - Rp 3/4

4 Drain valve connection - 3/4"

5 T&P valve connection - 1-11.5 NPT

6 Cleaning/inspection opening mm 95 x 70

7 Condensation drainage connection - Rp 1

Table 3.4 Gas data II2H3P

Description Unit DR-FC 80 DR-FC 95

Specifications for natural gas 2H: G20 - 20 mbar

Orifice diameter mm 7.00 7.60

(1) = flat sealing plate

(2) = burner pressure regulator

1 or 2 2 2

Nominal load (gross) kW 85.0 103.5

Nominal output kW 80.3 97.9

Supply pressure mbar 20 20

Burner pressure mbar 7.0 6.5

Gas consumption (1) m3/h 8.3 10.1

Specifications for LP gas 3P: G31 - 37 mbar (propane)

Orifice diameter mm 5.00 5.40

(1) = flat sealing plate

(2) = burner pressure regulator

1 or 2 2 2

Nominal load (gross) kW 83.2 101.2

Nominal output kW 80.3 97.8

Supply pressure mbar 37 37

Table 3.3 Dimensions

Dimensi

Description Unit DR-FC 80 DR-FC 95

Page is loading ...

Hamworthy Dorchester DR-FC 80-95 Installation guide

Brand: Hamworthy

Model: Dorchester DR-FC 80-95

Category: Water heaters & boilers

Type: Installation guide

Download PDF

report

Hamworthy Dorchester DR-FC 80-95 Installation guide

Hamworthy Dorchester DR-FC 80-95 Installation guide

Related papers

Other documents