A.O. Smith 30 User Manual

28 30 50 60

Installation

User and

Service Manual

www.aosmithinternational.com

your installer

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Read this manual carefully

Trademarks

Liability

Warning

Read this manual carefully before starting up the water heater. Failure to read this manual and to follow the instructions in this manual may lead to accidents, personal injury, and damage to the appliance.

Nothing from this publication may be copied, reproduced and/or published by means of printing, photocopying or by whatsoever means, without the prior written approval of A.O. Smith water Products Company.

A.O. Smith water Products Company reserves the right to modify specifications stated in this manual.

Any brand names mentioned in this manual are registered trademarks of their respective owners.

A.O. Smith water Products Company accepts no liability for claims from third parties arising from improper use other than that stated in this manual and in accordance with the General Conditions registered at the Eindhoven Chamber of Commerce.

Refer further to the General Conditions. These are available on request, free of charge.

Although considerable care has been taken to ensure a correct and suitably comprehensive description of all relevant components, the manual may nonetheless contain errors and inaccuracies.

Should you detect any errors or inaccuracies in the manual, we would be grateful if you would inform us. This helps us to further improve our documentation.

More information

If you have any comments or queries concerning any aspect related to the appliance, then please do not hesitate to contact:

A.O. Smith water Products Company

PO Box 70

5500 AB Veldhoven

Netherlands

Telephone: (free) 008008 - AOSMITH

0870 - 267 64 84

General: +31 40 294 25 00

Fax: +31 40 294 25 39

E-mail : info@aosmith.nl

Website: www.aosmithinternational.com

In the event of problems with connecting to the gas, electricity or water supply, please contact your installation's supplier/installation engineer .

Instruction manual SGS 3

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4 Instruction manual SGS

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Table of contents

1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

1.1 About the appliance - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

1.2 What to do if you smell gas- - - - - - - - - - - - - - - - - - - - - - - - - 9

1.3 Regulations - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

1.4 Target groups - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10

1.5 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10

1.6 Forms of notation - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10

1.7 Overview of this document - - - - - - - - - - - - - - - - - - - - - - - - 11

2 Working principle of the appliance- - - - - - - - - - - - - - - 13

2.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 13

2.2 General working principle of the appliance - - - - - - - - - - - - - - - - 13

2.3 The appliance's heating cycle - - - - - - - - - - - - - - - - - - - - - - 14

2.4 Protection for the appliance - - - - - - - - - - - - - - - - - - - - - - - 16

2.5 Safety of the installation - - - - - - - - - - - - - - - - - - - - - - - - - 17

2.6 Protection for the solar heating system - - - - - - - - - - - - - - - - - - 18

2.7 Safety of the solar heating system - - - - - - - - - - - - - - - - - - - - 19

3 Installation - - - - - - - - - - - - - - - - - - - - - - - - - - - 21

3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 21

3.2 Packaging - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 21

3.3 Environmental conditions- - - - - - - - - - - - - - - - - - - - - - - - - 21

3.4 Technical specifications - - - - - - - - - - - - - - - - - - - - - - - - - 24

3.5 Installation diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - 27

3.6 Water connections, Vented- - - - - - - - - - - - - - - - - - - - - - - - 28

3.7 Water connections, Unvented - - - - - - - - - - - - - - - - - - - - - - 29

3.8 Gas connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 30

3.9 Solar heating system- - - - - - - - - - - - - - - - - - - - - - - - - - - 30

3.10 Air supply and flue - - - - - - - - - - - - - - - - - - - - - - - - - - - - 30

3.11 Electrically connecting the appliance - - - - - - - - - - - - - - - - - - - 37

3.12 Electrically connecting the solar heating system controller- - - - - - - - - 40

3.13 Checking the supply pressure and burner pressure - - - - - - - - - - - - 43

4 Conversion to a different gas category - - - - - - - - - - - - 47

5 Filling - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51

5.1 Installation diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - 51

5.2 Filling unvented installations - - - - - - - - - - - - - - - - - - - - - - - 52

5.3 Filling vented installations - - - - - - - - - - - - - - - - - - - - - - - - 52

5.4 Filling solar heating system- - - - - - - - - - - - - - - - - - - - - - - - 53

6 Draining - - - - - - - - - - - - - - - - - - - - - - - - - - - - 55

6.1 Installation diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - 55

6.2 Draining unvented installations - - - - - - - - - - - - - - - - - - - - - - 56

6.3 Draining vented installations - - - - - - - - - - - - - - - - - - - - - - - 57

6.4 Draining solar heating system - - - - - - - - - - - - - - - - - - - - - - 58

7 The control panel- - - - - - - - - - - - - - - - - - - - - - - - 59

7.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 59

7.2 Controls - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 59

7.3 Meaning of icons- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 59

Instruction manual SGS 5

Table of contents

7.4 Electronic controller ON/OFF switch - - - - - - - - - - - - - - - - - - - - 59

7.5 Navigation buttons - - - - - - - - - - - - - - - - - - - - - - - - - - - - 60

7.6 PC connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 60

8 Status of the appliance - - - - - - - - - - - - - - - - - - - - - 61

8.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 61

8.2 Operating modes - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 61

8.3 Error conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 62

8.4 Service condition - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 62

8.5 Q/T Sensor warning - - - - - - - - - - - - - - - - - - - - - - - - - - - - 62

8.6 Collector temperature warning- - - - - - - - - - - - - - - - - - - - - - - 62

9 Starting and running - - - - - - - - - - - - - - - - - - - - - - 63

9.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 63

9.2 Starting the appliance - - - - - - - - - - - - - - - - - - - - - - - - - - - 63

9.3 The appliance's heating cycle - - - - - - - - - - - - - - - - - - - - - - - 63

10 Shutting down - - - - - - - - - - - - - - - - - - - - - - - - - 65

10.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 65

10.2 Shut the appliance down for a brief period ("OFF mode") - - - - - - - - - - 65

10.3 Electrically isolating the appliance - - - - - - - - - - - - - - - - - - - - - 65

10.4 Shutting the appliance down for a long period - - - - - - - - - - - - - - - 65

11 Main menu - - - - - - - - - - - - - - - - - - - - - - - - - - - 67

11.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 67

11.2 Notational convention for menu-related instructions - - - - - - - - - - - - 67

11.3 Switching on the "ON mode" - - - - - - - - - - - - - - - - - - - - - - - 67

11.4 Setting the water temperature - - - - - - - - - - - - - - - - - - - - - - - 67

11.5 Week program - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 68

11.6 Starting and stopping the week program - - - - - - - - - - - - - - - - - - 68

11.7 Changing the appliance's standard week program - - - - - - - - - - - - - 68

11.8 Adding times to a week program- - - - - - - - - - - - - - - - - - - - - - 70

11.9 Deleting times from a week program- - - - - - - - - - - - - - - - - - - - 71

11.10 Extra period- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 71

11.11 Programming an extra period - - - - - - - - - - - - - - - - - - - - - - - 72

11.12 Settings- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 73

12 Service program - - - - - - - - - - - - - - - - - - - - - - - - 75

12.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 75

12.2 Setting the hysteresis - - - - - - - - - - - - - - - - - - - - - - - - - - - 75

12.3 Displaying the error history - - - - - - - - - - - - - - - - - - - - - - - - 75

12.4 Displaying the appliance history - - - - - - - - - - - - - - - - - - - - - - 75

12.5 Display the selected appliance - - - - - - - - - - - - - - - - - - - - - - 76

12.6 Setting the service interval - - - - - - - - - - - - - - - - - - - - - - - - 76

12.7 Setting legionella prevention- - - - - - - - - - - - - - - - - - - - - - - - 76

12.8 Solar heating system configuration - - - - - - - - - - - - - - - - - - - - 76

12.9 Setting the central heating configuration - - - - - - - - - - - - - - - - - - 78

13 Troubleshooting - - - - - - - - - - - - - - - - - - - - - - - - 79

13.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 79

13.2 Troubleshooting table for general errors - - - - - - - - - - - - - - - - - - 80

13.3 Troubleshooting table for displayed errors - - - - - - - - - - - - - - - - - 83

13.4 Displayed warnings - - - - - - - - - - - - - - - - - - - - - - - - - - - - 94

6 Instruction manual SGS

14 Maintenance frequency - - - - - - - - - - - - - - - - - - - - 95

14.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 95

14.2 Determining service interval - - - - - - - - - - - - - - - - - - - - - - - 95

15 Performing maintenance - - - - - - - - - - - - - - - - - - - - 97

15.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 97

15.2 Preparation for maintenance - - - - - - - - - - - - - - - - - - - - - - - 97

15.3 Water-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - 99

15.4 Gas-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 100

15.5 Solar collector maintenance - - - - - - - - - - - - - - - - - - - - - - -100

15.6 Finalizing maintenance- - - - - - - - - - - - - - - - - - - - - - - - - - 100

16 Warranty (certificate) - - - - - - - - - - - - - - - - - - - - - - 101

16.1 General warranty - - - - - - - - - - - - - - - - - - - - - - - - - - - - 101

16.2 Tank warranty - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 101

16.3 Conditions for Installation and use - - - - - - - - - - - - - - - - - - - - 101

16.4 Exclusions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 102

16.5 Scope of the warranty - - - - - - - - - - - - - - - - - - - - - - - - - - 102

16.6 Claims - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -102

16.7 Obligations of A.O. Smith - - - - - - - - - - - - - - - - - - - - - - - - 102

17 Appendices - - - - - - - - - - - - - - - - - - - - - - - - - - - 103

17.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 103

17.2 Menu structure- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 104

17.3 Electrical diagram for the appliance- - - - - - - - - - - - - - - - - - - - 106

17.4 Electrical diagram, solar heating system - - - - - - - - - - - - - - - - - 108

17.5 Week program card - - - - - - - - - - - - - - - - - - - - - - - - - - - 111

Instruction manual SGS 7

Table of contents

8 Instruction manual SGS

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0063

1 Introduction

1.1 About the appliance

1.2 What to do if you smell gas

This manual describes how to install, service and use the SGS appliance. The SGS appliance is a condensing boiler with a fan in the air intake. The appliance is always supplied including a storage tank fitted with a heat exchanger connected to a solar energy source.

The SGS can be installed as either an open or room-sealed appliance. A concentric chimney connector is fitted standard to the appliance, but a parallel system can also be connected.

The alternative installation types are B23, C13, C33, C43, C53 and C63. The information in this manual applies to the: SGS 28, SGS 30, SGS 50 and

SGS 60. The appliance has been manufactured and equipped in accordance with the

European standard for gas-fired storage water heaters for the production of domestic hot water (EN 89). The appliances are therefore compliant with the European Directive for Gas Appliances, and are entitled to bear the CE mark.

Warning

Read this manual carefully before starting up the installation. Failure to read the manual and to follow the printed instructions may lead to personal injury and damage to the appliance.

Warning

If there is a gas smell:

No naked flames! No smoking!

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

1.3 Regulations

Open windows and doors!

Shut off the mains gas supply valve!

Warn occupants and leave the building!

After leaving the building, alert the gas distribution company or your installation engineer.

As the (end) user, installation engineer or service and maintenance engineer, you must ensure that the entire installation complies, as a minimum, with the official local:

• building regulations;

• energy supplier's directives for existing gas installations;

• directives and technical guidelines for natural gas installations;

• safety requirements for low-voltage installations;

• regulations governing the supply of drinking water;

• regulations governing ventilation in buildings;

• regulations governing the supply of air for combustion;

• regulations governing the discharge of products of combustion;

• requirements for installations that consume gas;

• regulations governing indoor waste water disposal;

• regulations imposed by fire brigade, power companies and municipality.

Instruction manual SGS 9

Introduction

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Furthermore, the installation must comply with the manufacturer's instructions.

Note

Later amendments and/or additions to all regulations, requirements and guidelines published on or prior to the moment of installing, will apply to the installation.

1.4 Target groups

1.5 Maintenance

The three target groups for this manual are:

• (end) users;

• installation engineers;

• service and maintenance engineers.

Symbols on each page indicate the target groups for whom the information is intended. See the table.

Target group symbols

Symbol Target group

(End) user

Installation engineer

Service and maintenance engineer

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.

Note

To determine the correct maintenance frequency, it is recommended to arrange for the service and maintenance engineer to check the appliance on both the water and gas side within three months following installation. Based on this check, the best maintenance frequency can be determined.

Note

Regular maintenance extends the service life of the appliance.

Note

Both the end user and the service and maintenance engineer are responsible for regular maintenance. They will need to establish clear agreements on this.

Note

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

1.6 Forms of notation

10 Instruction manual SGS

The following notation is used in this manual:

Note

Important information.

Caution

Ignoring this information can lead to the appliance being damaged.

Warning

Failure to carefully read this information may lead to personal injury and

serious damage to the appliance.

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1.7 Overview of this document

Chapter Target groups Description

Working principle of the appliance

Installation This chapter describes the installation activity to be

This chapter describes the working principle of the appliance.

completed before you start the appliance for the first time.

Conversion to a different gas category

Filling This chapter describes how to fill the appliance.

Draining This chapter describes how to drain the appliance.

The control panel This chapter describes the general control of the

Status of the appliance This chapter describes the status (mode or condition) that

Starting and running This chapter describes how to start the appliance running.

Shutting down This chapter describes how to shut the appliance down for

Main menu This chapter describes the main menu of the display. This

Service program This chapter describes the service menu. It is mainly

Troubleshooting This chapter is mainly intended for the installation

Maintenance frequency This chapter describes how to determine the optimum

This chapter describes the activities required to convert the appliance to a different gas category.

appliance using the display.

the appliance may have, and possible actions to take.

The general heating cycle of the appliance is also described.

a brief or long period of time.

is the actual menu for the user, however the installation engineer and service and maintenance engineers will also need to use this menu.

intended for the installation engineer and service and maintenance engineers. End users may also refer to this chapter for additional information about the appliance.

engineer and the service and maintenance engineer. It describes appliance 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 appliance.

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.

Note

If the appliance is not regularly maintained, the

warranty will become void.

Performing maintenance This chapter sets out the maintenance tasks to be carried

out during a service.

Warranty (certificate) This chapter states the warranty terms and conditions.

Instruction manual SGS 11

Introduction

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12 Instruction manual SGS

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2 Working principle of

the appliance

2.1 Introduction

2.2 General working principle of the appliance

Topics covered in this chapter:

• General working principle of the appliance;

• The appliance's heating cycle;

• Protection for the appliance;

• Safety of the installation;

• Protection for the solar heating system.

The figure shows a cut-away view of the appliance.

In this appliance, the cold water enters the bottom of the tank through the cold water inlet (14).

Once the appliance and the storage reservoir are completely filled with water, they are both constantly under mains water pressure. When hot water is drawn from the appliance, it is immediately replenished with hot water from the storage tank, which in turn is replenished with cold water. The water in the storage tank is heated by a heat exchanger which is connected to the solar heating system.

A gas-fired heat exchanger (11) in the appliance heats the tap water further if necessary. The air required by the latter for combustion is forced into the burner (17) by the fan (18).

The heated tap water leaves the tank through the hot water outlet (2). Once the appliance is completely filled with water, it will constantly be under mains water pressure. When hot water is drawn from the appliance, it is immediately replenished with cold water.

The gas is fed to the burner via the gas control (16). The modulated supply of gas and air ensures that the optimum gas/air mixture is always achieved. The special construction of the burner causes the mixture to form a vortex (cyclone effect) before it becomes ignited. This vorticity improves the ignition on the hot surface igniter (20), as well as ensuring optimum combustion efficiency. The special design of the heat exchanger (11) ensures that the flue gases are first led downwards via the combustion chamber, then upwards via the heat exchanger, and downwards again alongside the water in the tank. The flue gases gradually become cooler in the process. 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 transferred to the cooler water, thereby increasing the performance of the unit. The condensate yielded by this process is discharged via the siphon (23).

Heat losses are prevented by the insulating layer (24) in both the storage tank and the appliance itself. Both are enamel-coated on the inside to protect against corrosion. The anodes (9) provide extra protection against corrosion. Both are fitted with an inspection and cleaning opening (12) for maintenance purposes.

Instruction manual SGS 13

Legend

Only applicable numbers are mentioned.

1. cover

2. hot water outlet

3. electrical connector block

4. electronic controller

5. pressure switch

6. control panel

7. temperature sensor T

8. combustion chamber

9. anode

10. tank

11. heat exchanger

12. inspection and cleaning opening

13. temperature sensor T

14. cold water inlet

15. drain valve

16. gas control

17. burner

18. fan

19. air supply hose

20. hot surface igniter

21. flame probe

22. chimney pipe

23. siphon

24. insulation layer

29. pallet

Working principle of the appliance

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Cut-away view of the appliance

2.3 The appliance's heating cycle

The net water temperature (T the gas burner and the solar heating system are started and stopped. T curve shown in the figure. The controller uses two measured values to calculate this temperature: T are used by the controller of the solar heating system. S1 is measured in the solar collector. S2 is located between the inlet and outlet of the heat exchanger of the storage tank. S

Depending on whether or not hot water is being drawn off, hot water can be pumped from the storage tank to the appliance. This happens when S higher than T causing hot water to flow from the storage tank into the appliance. The pump switches off as soon as S

The other settings that govern the control behaviour are:

(7) and T2 (13). In addition, temperatures S1, S2 and S3

is measured at the top side of the storage tank.

. Water is then pumped from the appliance to the storage tank,

net

) in the appliance is used to regulate when both

net

equals T

net

is the

net

is 5 oC

14 Instruction manual SGS

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•T

set

is the the required water temperature that has been set on the

set

appliance (11.4.1 "Setting the water temperature via the SET POINT

MENU"). As soon as T

falls below T

net

, the water heating via the solar

set

heating system is started, however, only if the temperature of the heating fluid (S measured at the appliance (sensor S2). As soon as (T

) is a certain (adjustable) value higher than the temperature

net

= T

set

= T heating via the solar heating system is stopped. There is one exception to this rule, and that is when T

solar limit

is set to a higher value than T

• Hysteresis The moment T

falls below (T

net

set

- T

- Hysteresis), the controller

solar diff

registers such a heat demand that the gas burner and the solar heating system jointly heat the water. The solar heating system is only employed when the temperature measured by S than that of S

•T

solar diff

When T

exceeds (T

net

set

- T

solar diff

is heated exclusively by the solar heating system. When T T

set

value of T

•T

solar limit

(provided

solar diff

Tse t

= T

solar limit

), the solar heating system switches off. The

is adjustable (12.8.5 "Setting the solar difference").

is a certain (adjustable) value grater

), the gas burner is shut off and the water

rises above

net

Preset (12.8.4 "Setting the solar limit temperature") water temperature at which heating via the solar heating system is stopped.

solar limit

set

Legend

A = Gas burner on B = Gas burner off

net

• = no heat demand, so water not heated

• = water heated via solar heating system

• = water heated via solar heating system and gas burner

t = time T = Temperature

C = Minimum tap water

temperature

Graphical representation of heating cycle

solar limit

set

Solar diff.

Hys.

min = 45C

Note

can rise above T

net

,. However, this is only possible if T

set

increased via the service menu.

Note

to T

set

can be lower than T

solar limit

; this will mean that T

set

solar limit

can never be equal

net

Instruction manual SGS 15

2.4 Protection for the appliance

2.4.1 Introduction

2.4.2 Appliance water temperature protection

Working principle of the appliance

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The electronic controller monitors the water temperature, helps ensure the safe use of the solar heating system, and ensures safe combustion. This takes place using:

• the Appliance water temperature protection

• the Gas valve

• the Fan

• the Pressure switch

• the Flame probe

The electronic controller uses temperature sensors T1 (7) and T2 to monitor several temperatures that are important for safety.

The table explains the functioning of these temperature sensors.

Temperature protection

Protection Description

Against frost:

- T1 < 5°C

- T2 < 5°C

For maximum water temperature:

- T1 > 85°C

- T2 > 85°C

For extra safety:

> 93°C

- T

> 93°C

- T

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

The high-limit safeguard serves to prevent overheating and/or excessive formation of scale in the appliance. If the high-limit safeguard is activated, the heating is stopped. This causes the water in the tank to cool down. Once the water has cooled sufficiently (T1 < 78°C), the electronic controller resets the appliance.

A lockout error of the water heater controller takes place. The controller must be manually reset before the appliance can resume operation (8.3 "Error

conditions"). The reset may only be performed if T

2.4.3 Water temperature protection for the storage tank

Using temperature sensors S2 and S3, the solar heating system controller monitors several temperatures in the storage tank that are related to safety.

Temperature protection

Protection Description

Against frost:

- S2, S3 < 5°C

For maximum water temperature:

, S3 > 85°C

- S

For extra safety:

, S3 > 93°C

- S

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

The high-limit safeguard serves to prevent overheating and/or excessive formation of scale in the storage tank. If the high-limit safeguard is activated, the heating is stopped. This causes the water in the storage tank to cool down. Once the water has cooled sufficiently (S resets the appliance.

A lockout error of the water heater controller takes place. The controller must be manually reset before the appliance can resume operation (8.3 "Error

conditions"). The reset may only be performed if S

<78°C.

< 78°C), the electronic controller

< 78°C.

2.4.4 Gas valve

The electronic controller opens the gas valve so that gas can be supplied to the burner. As a safety measure, the gas valve has a double shut-off. The double shut-off guarantees complete isolation of the appliance from the gas supply.

To help ensure smooth ignition, the gas valve opens gradually ('softlite").

16 Instruction manual SGS

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2.4.5 Fan

The fan (18) provides an optimum air supply when there is a heat demand. As a safety feature, the fan ensures that any gases present in the combustion chamber are removed, both before and after combustion. We refer to this as pre- and post-purge.

The fan speed is continuously monitored by the electronic controller (4). The electronic controller takes control if the speed of rotation varies too much from the set value.

2.4.6 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 appliance. The default state of the pressure switch is open. When sufficient pressure difference is reached, the pressure switch closes. However, in the event of a fault, the pressure switch is tripped open, and the heating cycle is interrupted. The table shows the trip point per appliance.

Note

The trip point of the pressure switch is not adjustable.

Pressure switch trip points

2.5 Safety of the

installation

Appliance Closing pressure

difference

SGS 28 >

SGS 30 >

SGS 50 >

SGS 60 >

635 Pa < 605 Pa

855 Pa < 825 Pa

885 Pa < 855 Pa

1085 Pa < 1055 Pa

2.4.7 Flame probe

To ensure that no gas can flow when there is no combustion, the water heater is fitted with a flame probe (21). The electronic controller uses this probe to detect the presence of a flame, by means of ionisation detection. The electronic controller closes the gas control the instant it detects that there is a gas flow but no flame.

In addition to the appliance's standard built-in safety monitoring, the appliance must also be protected by an expansion vessel, expansion valve, pressure reducing valve, non-return valve and a T&P valve.

The use of an expansion vessel, expansion valve and/or pressure reducing valve depends on the type of installation: unvented or vented.

2.5.1 Unvented installation

With an unvented installation, an expansion valve valve and expansion vessel prevent the buildup of excessive pressure in the tank. This prevents damage being caused to the enamelled coating (in the appliance) or to the tank. A nonreturn valve prevents excessive pressure buildup 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 (> 8 bar). These components are fitted to the cold water pipe (3.6 "Water connections, Vented").

Opening pressure difference

Instruction manual SGS 17

2.5.2 Vented installation

2.5.3 T&P valve

2.6 Protection for the solar heating system

Working principle of the appliance

gis

With a vented installation, excess pressure is taken up by the open cold water head tank. The height of the head tank determines the working pressure in the water heater, which may not exceed 8 bar. The installation must also be fitted with a vent pipe from the hot water pipe, that opens into the cold water tank.

Ideally, the vent pipe should discharge into a separate tundish/drain or otherwise to the open cold water head tank. The water heater should also be fitted on the hot water side with a stop valve (3.7.2 "Hot water side").

A T&P valve is only mandatory in an unvented installation. However, A.O. Smith also recommends the use of a T&P valve in vented installations.

A T&P (Temperature and Pressure Relief) valve monitors the pressure in the tank and the water temperature at the top of the tank. If the pressure in the tank becomes excessive (> 10 bar) or the water temperature is too high (> 97°C), the valve will open. The hot water can now flow out of the tank. Because the appliance is under water supply pressure, cold water will automatically flow into the tank. The valve remains open until the unsafe situation has been rectified. The appliance is fitted standard with a connecting point for a T&P valve (3.7.2 "Hot water side").

2.6.1 Drain-back tank

The solar heating system may optionally be equipped with a drain-back tank. The tank fills itself with the heating fluid when there is no heat demand. This avoids overheating of the solar heating system. The high insulation factor of the tank also protects the system from freezing of the fluid. The use of the drainback tank also serves to extend the useful life of the fluid.

The presence of a drain-back tank is set (12.8.1 "Setting the drain-back tank") during the installation. Refer to the solar heating system manual for more details.

2.6.2 Fluid temperature

The heat exchanger of the solar heating system may be filled with glycol. If the temperature of the heating fluid is too high, a signal is sent to the controller of the solar collector and the pump of the solar collector is switched off. This signal is passed to the controller by temperature sensor S

At present, no heating fluids other than glycol are supported. The heating fluid type is set (12.8.2 "Setting the heating fluid type in the solar heating system") during installation.

Temperature protection for solar heating system

Protection Description

Maximum temperature S heating system is filled with glycol:

- S

> 130°C

, if solar

The pump of the solar heating system switches off when the temperature of the heating fluid at S value. The solar heating system enters error mode. The error is also visible on the display of the SGS appliance

exceeds the maximum

18 Instruction manual SGS

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2.7 Safety of the solar

heating system

2.7.1 Expansion vessel

2.7.2 Expansion valve

The solar heating system must be equipped with an expansion vessel (16). An expansion vessel serves to limit pressure variations in the system. The expansion vessel in the solar heating system can withstand a maximum pressure of 6 bar. The supply pressure to the expansion vessel depends on the static head of the system.

Besides the expansion vessel, the system is protected from overpressure by an expansion valve (2.7.2 "Expansion valve").

The solar heating system is equipped with an expansion valve (23). The expansion valve monitors the pressure in the solar heating system. If the pressure is excessive (> 6 bar), then the valve will open. The hot water can now flow out of the installation. The valve remains open until the unsafe situation has passed, i.e. until the pressure has fallen back below 6 bar.

Note

Because the installation is always under pressure and is not automatically

filled, the system will again need to be replenished (5 "Filling").

Instruction manual SGS 19

Working principle of the appliance

gis

20 Instruction manual SGS

3 Installation

Warning

Installation work should be carried out by an approved installation engineer in compliance with the general and local regulations imposed by the gas, water and power supply companies and the fire service.

The appliance may only be installed in a room that complies with the requirements stated in national and local ventilation regulations (1.3 "Regulations").

3.1 Introduction

3.2 Packaging

This chapter describes the installation activities to be carried out before you actually start using the appliance (9 "Starting and running"), namely:

• Packaging;

• Environmental conditions;

• Technical specifications;

• Water connections, Vented;

• Water connections, Unvented;

• Water connections, Vented;

• Gas connection;

• Solar heating system;

• Air supply and flue;

• Electrically connecting the appliance;

• Checking the supply pressure and burner pressure.

For conversion to a different gas category, see conversion (4 "Conversion to a

different gas category").

To avoid damaging the appliance, remove the packaging carefully.

We recommend unpacking the appliance at or near its intended location.

Caution

The appliance may only be manoeuvred in an upright position. Take care that the appliance is not damaged after unpacking.

3.3 Environmental conditions

Instruction manual SGS 21

The appliance is suitable for either open or room-sealed combustion. If installed as a room-sealed appliance, then the availability of the necessary external air supply will depend on the place of installation. In this event, there are no additional ventilation requirements.

If the appliance is to be installed as an open system, then it will be subject to the guidelines and ventilation regulations that are in force locally.

The alternative installation types are B23, C13, C33, C43, C53 and C63.

Caution

The appliance may not be used in rooms where chemical substances are stored or used, due to the risk of explosion and/or corrosion of the appliance. Some propellants, bleaching agents, degreasing agents etc. disperse vapours which are explosive and/or which cause accelerated corrosion. If the appliance is used in a room in which such substances are present, the warranty will be void.

Installation

3.3.1 Air humidity and ambient temperature

The boiler room must be frost-free, or be protected against frost. The table shows the environmental conditions that must be adhered to for correct functioning of the electronics present in the appliance to be guaranteed.

Air humidity and ambient temperature specifications

Air humidity and ambient temperature

Air humidity max. 93% RV at +25°C

Ambient temperature Functional: 0 <

3.3.2 Maximum floor load

In regard to the total weight of the installation, bear in mind that the installation always comprises an appliance complete with storage tank.

Appliance maximum floor load

In connection with the appliance's weight, take account of the maximum floor loading, refer to the table.

Weight specifications related to maximum floor load

T < 60°C

Weight of the appliance filled with water

SGS 28 394 kg

SGS 30, SGS 50, SGS 60 582 kg

Maximum floor load of storage tank

Bear in mind the weight of the storage tank (completely filled with water) when considering the maximum floor load. This maximum floor load may be between 400 and 4500 kg. This depends on the type of storage tank .

3.3.3 Water composition

The appliance is intended for heating drinking water. The drinking water must comply with the regulations governing drinking water for human consumption. The table gives an overview of the specifications.

Water specifications

Water composition

Hardness (alkaline earth ions)

Conductivity > 125 µS/cm

Acidity (pH value) 7,0 < pH value < 9.5

> 1.00 mmol/l:

• German hardness > 5.6° dH

• French hardness > 10.0° fH

• British hardness > 7.0° eH

Note

If the water specifications deviate from those stated in the table, the storage

tank protection cannot be guaranteed (16 "Warranty (certificate)").

If the water hardness is greater than 4° dH, please contact A.O. Smith.

22 Instruction manual SGS

3.3.4 Appliance working clearances

For access to the appliance, it is recommended that the following clearances are observed:

• AA: around the appliance's control column and cleaning openings: 100 cm.

• BB: all sides of the appliance: 50 cm

• Above the appliance (room to replace the anodes):

- 100 cm if using rigid anode(s), or

- 50 cm if using flexible anode(s). If the available clearance is less than 100 cm, flexible magnesium anodes

can be ordered.

Note

When installing the appliance, be aware that any leakage may cause damage to the immediate environment or floors below the level of the boiler room. If this is the case, then the appliance should be installed above a wastewater drain or in a suitable metal leak tray.

3.3.5 Storage tank working clearances

For access to the storage tank, it is recommended that the following clearances are observed:

• All sides of the storage tank: 50 cm.

• Above the storage tank (room to replace the anodes): 100 cm.

Note

When installing the storage tank, be aware that any leakage can cause damage to the immediate environment or floors below the level of the boiler room. If this is the case, then the appliance should be installed above a wastewater drain or in a suitable metal leak tray.

Working clearances

A A

IMD-0227 R2

Instruction manual SGS 23

Installation

3.4 Technical specifications

Legend

See the table.

The appliance is supplied without accessories. Check the dimensions (3.4.1 "Dimensions of the appliance"), gas data (3.4.3 "Gas data") and other specifications (3.4.2 "General and electrical specifications") of any accessories you plan to use.

3.4.1 Dimensions of the appliance

Plan and elevation of the appliance

24 Instruction manual SGS

Dimensions (all dimensions in mm, unless otherwise stated)

Dimen

Description SGS 28 SGS 30 SGS 50 SGS 60

sion

A Total height 1485 2005 2005 2005

C Position on pallet 490 490 490 490

D Appliance diameter 705 705 705 705

E Depth 925 925 925 925

F Width 850 850 850 850

G Diameter of chimney flue 80/125 100/150 100/150 100/150

H Height of chimney flue 1460 2000 2000 2000

Hx x position of chimney flue outlet 265 265 265 265

Hy y position of chimney flue outlet 375 375 375 375

K Height of gas/burner connection 1365 1895 1895 1895

M Height of cold water supply 265 255 255 255

N Height of hot water outlet 1485 2005 2005 2005

Ny y position of hot water outlet 205 205 205 205

P Height of cleaning opening 265 270 270 270

R Height of drain valve connection 180 170 170 170

S Height of T&P valve connection 995 1505 1505 1505

W Height of condensation drain 220 240 240 240

1 Cold water supply connection (male) R1

2 Hot water outlet (male) R11/

3 Gas control connection (female) Rp3/

4 Drain valve connection (female)

/4"

R11/

Rp3/

/4"

R11/

Rp3/

/4"

R11/

Rp3/

/4"

5 T&P valve connection (female) 1 - 11.5 NPT 1 - 11.5 NPT 1 - 11.5 NPT 1 - 11.5 NPT

6 Cleaning/inspection opening 95 x 70 95 x 70 95 x 70 95 x 70

7 Condensation drainage connection (female) Ø40 Rp 1 Rp 1 Rp 1

3.4.2 General and electrical specifications

General and electrical specifications

DESCRIPTION Unit SGS 28 SGS 30 SGS 50 SGS 60

Volume litres 217 368 368 368

Empty weight kg 177 214 214 214

Maximum operating pressure bar 8 8 8 8

Number of anodes - 4 4 4 4

Fan speed at ignition rpm 4500 4500 4500 4500

Working speed of fan rpm 5000 5400 6000 6660

Diameter of air restrictor mm 23.0 23.0 28.0 29.0

Heating-up time ∆T = 45°C minutes 22 35 24 19

Electrical power consumption W 275 275 275 275

Maximum power consumption of solar

W 700 700 700 700

heating system controller

Supply voltage (-15% +10% VAC) volts 230 230 230 230

Mains frequency Hz (± 1Hz) 50 50 50 50

IP class - 30 30 30 30

Instruction manual SGS 25

Installation

3.4.3 Gas data

Gas data

Description II

Gas category 2H: G20 - 20 mbar

Injector orifice diameter mm 4.90 5.10 7.00 7.10

(1) = Blank plate (2) = Burner pressure regulator

Nominal load (gross calorific value) kW 32.1 34.5 52.6 63.2

Nominal output kW 30.5 32.7 48.8 59.6

Supply pressure mbar 20 20 20 20

Burner pressure mbar 8.5 8.5 8.5 11.5

Gas consumption

General 3+

Injector orifice diameter mm 2.50 2.60 3.40 3.80

(1) = Blank plate (2) = Burner pressure regulator

Gas category: G30-30 mbar (butane)

Nominal load (gross calorific value) kW 30.7 32.8 50.6 59.4

Nominal output kW 29.8 31.8 48.1 57.4

Supply pressure mbar 30 30 30 30

Burner pressure

Gas consumption

Gas category: G31-37 mbar (propane)

Nominal load (gross calorific value) kW 29.0 30.9 50.3 59.1

Nominal output kW 28.1 29.8 47.7 56.9

Supply pressure mbar 37 37 37 37

Burner pressure

Gas consumption

(*) Based on 1013.25 mbar and 15 °C. (†) If using a blank plate instead of a burner pressure regulator, it is assumed that the burner pressure is equal to

the supply pressure. In practice, however, the burner pressure will be lower.

2H3+

(*)

(†)

(*)

(†)

(*)

Unit SGS

1 or 2 2 2 2 2

m3/h 3.1 3.3 5.0 6.0

1 or 2 1 1 1 1

mbar----

kg/h 2.2 2.4 3.7 4.3

mbar----

kg/h 2.1 2.2 3.6 4.2

SGS 30

SGS 50

SGS 60

26 Instruction manual SGS

3.5 Installation diagram

This figure shows the installation diagram. This diagram is used in the sections in which the actual connection process is described.

Installation diagram

Instruction manual SGS 27

Installation

Legend

Only applicable numbers are mentioned.

1. pressure-reducing valve (mandatory if the mains

water pressure exceeds 8 bar)

3. T&P valve (mandatory)

4. stop valve (recommended in pipe C and mandatory in

pipe A)

5. non-return valve (mandatory)

6. circulation pump (optional)

9. drain valve

10. manual gas valve (mandatory)

11. service stop valve (recommended)

12. temperature gauge (recommended)

13. condensation drainage (mandatory)

14. hot water draw-off points

16. expansion vessel (mandatory)

17. 3-way aeration valve (recommended)

18. water tank

Note

In the above diagram, there is a non-return valve in the station. This may only be used in closed (pressure) systems. In systems with drain back, it is prohibited to fit a non-return valve in the solar heating system.

19. float valve

23. pressure valve (mandatory)

26. air bleed (mandatory)

37. combined Q/T sensor (optional)

38. solar heating system pump station (modulating mandatory)

A. cold water supply B. hot water supply C. circulation pipe D. gas supply E. overflow pipe F. heat exchanger supply G. heat exchanger return H. overflow safety S1.collector sensor (mandatory) S2.tank sensor (mandatory) S3.top tank sensor (mandatory) S4.heat exchanger discharge sensor (optional)

3.6 Water connections, Vented

3.6.1 Cold water side

3.6.2 Hot water side

Warning

The installation should be carried out by an authorised installation engineer,

in compliance with general and local regulations (1.3 "Regulations").

See (A) in the installation diagram (3.5 "Installation diagram").

1. Fit an approved stop valve (4) on the cold water side between the cold water head tank (18) and the appliance, as required by regulations (1.3 "Regulations").

See (B) in the installation diagram (3.5 "Installation diagram").

Note

Insulating long hot water pipes prevents unnecessary energy loss.

1. Fit the T&P valve (3).

2. Optional: fit a temperature gauge (12) so you can check the temperature of the tap water.

3. Fit a stop valve (11) in the hot water outlet pipe for servicing.

4. If a circulation pipe is required, continue by installing the circulation pipe (3.6.3 "Circulation pipe").

28 Instruction manual SGS

3.6.3 Circulation pipe

See (C) in the installation diagram (3.5 "Installation diagram").

If an immediate flow of hot water is required at draw-off points, a circulation pump can be installed. This improves comfort and reduces water wastage.

1. Fit a circulation pump (6) of the correct capacity for the length and resistance of the circulation system.

2. Fit a non-return valve (5) behind the circulation pump to guarantee the direction of circulation.

3. Fit two stop valves for service purposes (4).

4. Connect the circulation pipe up to a connection of the storage tank.

3.7 Water connections, Unvented

3.7.1 Cold water side

3.7.2 Hot water side

Warning

The installation should be carried out by an authorised installation engineer,

in compliance with general and local regulations (1.3 "Regulations").

See (A) in the installation diagram (3.5 "Installation diagram").

1. Fit an approved stop valve (4) on the cold water side as required by applicable regulations (1.3 "Regulations").

2. The maximum working pressure of the appliance is 8 bar. Because the pressure in the water pipe at times can exceed 8 bar, you must fit an approved pressure-reducing valve (1).

3. Fit a non-return valve (5) and an expansion vessel (16).

4. Fit an expansion valve (15) and connect the overflow side to an open wastewater pipe.

See (B) in the installation diagram (3.5 "Installation diagram").

Note

Insulating long hot water pipes will prevent unnecessary energy loss.

1. Optional: fit a temperature gauge (12) so you can check the temperature of the tap water.

2. Fit the T&P valve (3).

3. Fit a stop valve (11) in the hot water outlet pipe for servicing.

3.7.3 Circulation pipe

See (C) in the installation diagram (3.5 "Installation diagram").

If an immediate flow of hot water is required at draw-off points, a circulation pump can be installed. This improves comfort and reduces water wastage.

1. Fit a circulation pump (6) of the correct capacity for the length and resistance of the circulation system.

2. Fit a non-return valve (5) behind the circulation pump to guarantee the direction of circulation.

3. Fit two stop valves for service purposes (4).

4. Connect the circulation pipe up to a connection of the storage tank

Instruction manual SGS 29

Installation

3.7.4 Condensation drainage

1. Fit a sloping wastewater pipe to the siphon (13) for condensation drainage and connect this to the wastewater discharge in the boiler room.

Caution

All fittings behind the siphon must be condensation-resistant.

3.8 Gas connection

3.9 Solar heating system

Warning

The installation should be carried out by an authorised installation engineer,

in compliance with general and local regulations (1.3 "Regulations").

Caution

Make sure that the diameter and length of the gas supply pipe are large

enough to supply sufficient capacity to the appliance.

See (D) in the installation diagram (3.5 "Installation diagram").

1. Fit a manual gas valve (10) in the gas supply pipe.

2. Blow the gas pipe clean before use.

3. Close the manual gas valve.

4. Fit the gas supply pipe to the gas control.

Warning

After fitting, check for leaks.

Note

For the solar heating system connections, refer to the electrical

diagram (17.4 "Electrical diagram, solar heating system") and the table. ( "Electrical connector block")

1. Connect the supply from the solar collector to the inlet (F) of the heat exchanger (55).

2. Connect the return pipe to the solar collector to the outlet (G) of the heat exchanger (55).

3. Connect the lead from the solar heating system controller to sensor S2, see:

- electrical diagram (17.3 "Electrical diagram for the appliance") and

- connections table (3.11.2 "Preparation").

4. Connect the communication cable between the solar heating system controller and the appliance, see:

- electrical diagram (17.4 "Electrical diagram, solar heating system") and

- connections table (3.11.2 "Preparation").

Warning

The installation diagram shows a non-return valve in the pump station. This

non-return valve may be used solely in closed (pressure) systems. In systems

with a drain-back tank, it is prohibited to fit a non-return valve in the solar heating system.

3.10 Air supply and flue

3.10.1 Introduction

This section covers the following subjects:

• Requirements for flue gas discharge materials

• Concentric connections

• Parallel connections

30 Instruction manual SGS

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