A.O. Smith Cyclone BFC-28 Troubleshooting guide

0310 878
Innovation has a name.
Installation, User and Service
Manual
High Efficient Condensing
Water Heater
BFC - 28/30/50/60/80/100/120
BFC

A.O. Smith UK, Unit B8 Amstrong Mall,
Southwood Business Park, Farnborough, Hampshire GU14 0NR
www.aosmith.co.uk
“A.O. Smith Water Heaters” is a trading name of Advance Services (Sales) Ltd. Reg.
your installer

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Errata
The amendments below apply to finishing of maintenance (15.5 "Finalizing maintenance").These instructions supersede
the previous instructions of the solar heating control.
15.5 Finalizing
maintenance
To finalize the maintenance, carry out the following steps:
1. Fill the water heater (5 "Filling").
2. Start the water heater (9 "Starting the water heater").
3. Check the CO2value (3.12.3 "CO2adjustment").
4. Check the switching pressure of the pressure switch. (3.12.4 "Switching pressure
measurement")
5. Erase the message SERVICE REQUIRED. The displayed message can be reset in
either of two ways.
1. Temporary reset:
To postpone the message, press RESET once. The message will reappear on the
display 7 days later.
2.Full reset:
To fully reset the message, press and hold both RESET and ENTER at the same
time for 5 sec.
On completion of the full reset of the message, the message below will appear on the
display. This message will NOT be shown after a temporary rest of the message.

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Instruction manual BFC 3
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Read this manual carefully Warning
Read this manual carefully before starting 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.
Copyright © 2013 A.O.Smith Water Products Company
All rights reserved.
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.
Trademarks Any brand names mentioned in this manual are registered trademarks of their
respective owners.
Liability A.O.Smith Water Products Company accepts no liability for claims from third
parties arising from unauthorised use, use other than that stated in this manual,
and use other than in accordance with the General Conditions registered at the
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 specific aspects related to the
water heater, then please do not hesitate to contact:
A.O.Smith Water Products Company
PO Box 70
5500 AB Veldhoven
The Netherlands
Telephone: (free) 0870-AOSMITH
0870-2676484
General: [phone]
Fax: [phone]
E-mail: [e-mail]
Website: aosmith.co.uk
In the event of problems with your gas, electricity or water supply connections,
please contact the supplier/installation engineer of your installation.

4Instruction manual BFC
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Instruction manual BFC 5
Contents
1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
1.1 About the water heater - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
1.2 What to do if you smell gas- - - - - - - - - - - - - - - - - - - - - - - - - 9
1.3 Regulations - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
1.4 Target groups - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10
1.5 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11
1.6 Notation conventions- - - - - - - - - - - - - - - - - - - - - - - - - - - 11
1.7 Overview of this document - - - - - - - - - - - - - - - - - - - - - - - - 12
2 Working principle of the water heater - - - - - - - - - - - - - 13
2.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 13
2.2 General working principle of the water heater - - - - - - - - - - - - - - - 13
2.3 Water heater operating cycle - - - - - - - - - - - - - - - - - - - - - - - 15
2.4 Protection for the water heater - - - - - - - - - - - - - - - - - - - - - - 15
2.5 Safety of the installation - - - - - - - - - - - - - - - - - - - - - - - - - 16
3 Installation - - - - - - - - - - - - - - - - - - - - - - - - - - - 17
3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17
3.2 Packaging - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17
3.3 Ambient conditions- - - - - - - - - - - - - - - - - - - - - - - - - - - - 17
3.4 Technical specifications - - - - - - - - - - - - - - - - - - - - - - - - - 19
3.5 Installation diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - 25
3.6 Unvented water connections - - - - - - - - - - - - - - - - - - - - - - - 26
3.7 Vented water connections - - - - - - - - - - - - - - - - - - - - - - - - 27
3.8 Gas connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 27
3.9 Air supply and chimney flue discharge - - - - - - - - - - - - - - - - - - 28
3.10 Electrical connection - - - - - - - - - - - - - - - - - - - - - - - - - - - 33
3.11 Check the supply pressure, gas controller pressure, CO2value and
switching pressure - - - - - - - - - - - - - - - - - - - - - - - - - - - - 36
4 Conversion to a different gas category - - - - - - - - - - - - 45
4.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 45
5 Filling - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47
5.1 Filling unvented installations - - - - - - - - - - - - - - - - - - - - - - - 48
5.2 Filling vented installations - - - - - - - - - - - - - - - - - - - - - - - - 48
6 Draining - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49
6.1 Draining unvented installations - - - - - - - - - - - - - - - - - - - - - - 50
6.2 Draining vented installations - - - - - - - - - - - - - - - - - - - - - - - 50
7 The control panel- - - - - - - - - - - - - - - - - - - - - - - - 51
7.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51
7.2 Control - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51
7.3 Explanation of icons - - - - - - - - - - - - - - - - - - - - - - - - - - - 51
7.4 ON/OFF switch on controller - - - - - - - - - - - - - - - - - - - - - - - 51
7.5 Navigation buttons - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51
7.6 PC connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 52
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Contents
6Instruction manual BFC
8 Status of the water heater - - - - - - - - - - - - - - - - - - - 53
8.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 53
8.2 Operating modes - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 53
8.3 Error conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 54
8.4 Service condition - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 54
8.5 Anode warning - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 55
9 Starting the water heater - - - - - - - - - - - - - - - - - - - - 57
9.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 57
9.2 Starting the appliance - - - - - - - - - - - - - - - - - - - - - - - - - - - 57
9.3 The appliance's heating cycle - - - - - - - - - - - - - - - - - - - - - - - 57
10 Shutting down - - - - - - - - - - - - - - - - - - - - - - - - - 59
10.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 59
10.2 Decommissioning the water heater for a short period- - - - - - - - - - - - 59
10.3 Isolating the water heater from the mains - - - - - - - - - - - - - - - - - 59
10.4 Decommissioning the water heater for a long period - - - - - - - - - - - - 59
11 Main menu - - - - - - - - - - - - - - - - - - - - - - - - - - - 61
11.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 61
11.2 Notation convention for menu-related instructions - - - - - - - - - - - - - 61
11.3 Switching to "ON mode" - - - - - - - - - - - - - - - - - - - - - - - - - - 61
11.4 Setting the water temperature - - - - - - - - - - - - - - - - - - - - - - - 61
11.5 Week program - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 62
11.6 Starting and stopping the week program - - - - - - - - - - - - - - - - - - 62
11.7 Changing the appliance's standard week program - - - - - - - - - - - - - 62
11.8 Adding times to a week program- - - - - - - - - - - - - - - - - - - - - - 64
11.9 Deleting times from a week program- - - - - - - - - - - - - - - - - - - - 65
11.10 Extra period - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 66
11.11 Settings- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 67
12 Service program - - - - - - - - - - - - - - - - - - - - - - - - 69
12.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 69
12.2 Setting the hysteresis - - - - - - - - - - - - - - - - - - - - - - - - - - - 69
12.3 Displaying the error history - - - - - - - - - - - - - - - - - - - - - - - - 69
12.4 Displaying the water heater history - - - - - - - - - - - - - - - - - - - - 69
12.5 Display the selected water heater - - - - - - - - - - - - - - - - - - - - - 70
12.6 Switching the pump on or off - - - - - - - - - - - - - - - - - - - - - - - 70
12.7 Setting the service interval - - - - - - - - - - - - - - - - - - - - - - - - 70
12.8 Service mode - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 70
12.9 Setting legionella prevention- - - - - - - - - - - - - - - - - - - - - - - - 71
13 Errors - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 73
13.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 73
13.2 Troubleshooting table for general errors - - - - - - - - - - - - - - - - - - 74
13.3 Troubleshooting table for displayed errors - - - - - - - - - - - - - - - - - 76
13.4 Warnings on the display - - - - - - - - - - - - - - - - - - - - - - - - - - 84
14 Service interval - - - - - - - - - - - - - - - - - - - - - - - - - 85
14.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 85
14.2 Determining service interval - - - - - - - - - - - - - - - - - - - - - - - - 85

Instruction manual BFC 7
15 Performing maintenance - - - - - - - - - - - - - - - - - - - - 87
15.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 87
15.2 Preparation for maintenance - - - - - - - - - - - - - - - - - - - - - - - 87
15.3 Water-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - 88
15.4 Gas-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 89
15.5 Finalizing maintenance- - - - - - - - - - - - - - - - - - - - - - - - - - 90
16 Warranty (certificate) - - - - - - - - - - - - - - - - - - - - - - 91
16.1 General warranty - - - - - - - - - - - - - - - - - - - - - - - - - - - - 91
16.2 Tank warranty - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 91
16.3 Conditions for Installation and use - - - - - - - - - - - - - - - - - - - - 91
16.4 Exclusions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 92
16.5 Scope of the warranty - - - - - - - - - - - - - - - - - - - - - - - - - - 92
16.6 Claims - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 92
16.7 Obligations of A.O.Smith - - - - - - - - - - - - - - - - - - - - - - - - - 92
17 Appendices- - - - - - - - - - - - - - - - - - - - - - - - - - - 93
17.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 93
17.2 Menu structure- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 94
17.3 Electrical diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - - 96
17.4 Declaration of conformity - - - - - - - - - - - - - - - - - - - - - - - - - 98
17.5 Week program card - - - - - - - - - - - - - - - - - - - - - - - - - - - 99

Contents
8Instruction manual BFC