baxi 624 Combi User guide

Please keep these instructions in a safe place.

If you move house please hand them over to the next occupier.

United Kingdom

en

User Guide

High Efficiency Wall Hung Condensing Gas Boiler

Baxi Combi

624 — 630

Dear Customer,

Thank you very much for buying this appliance.

Please read through the manual carefully before using the product, and keep it in a safe place for later reference. In order to
ensure continued safe and efficient operation we recommend that the product is serviced regularly. Our service and customer
service organisation can assist with this.

We hope you enjoy years of problem-free operation with the product.

Contents

7679305 - 1 - 14082017 3

Contents

1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.1 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.2 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.2.1 The Benchmark Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.2.2 Benchmark Commissioning Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.3 Liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.3.1 User's liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

1.3.2 Installer's liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.3.3 Manufacturer's liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2 About this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.2 Additional documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.3 Symbols used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.3.1 Symbols used in the manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.4 Abbreviations/glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3 Technical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.1 Homologations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.1.1 Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.2 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

3.2.1 Technical information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

3.2.2 Dimensions and connections/clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4 Description of the product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

4.2 Operating principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.2.1 In operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.3 Control panel description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.3.1 Description of the control panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.4 Accessories and options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.4.1 Optional accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

5.1 Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.1.1 Operation checking procedure & basic fault identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2 Use of the control panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.2.1 Using the control panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.3 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.4 Frost protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6.2 Maintenance instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6.2.1 Re-pressurising the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6.3 Venting the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6.4 Draining the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

7 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

7.1 Error codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

7.1.1 List of error codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

7.2 Fault finding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

8 Decommissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

8.1 Decommissioning procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

9 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

9.1 Disposal and recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

10 Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

10.1 Energy saving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

10.2 Room thermostats and settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

11 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Contents

4 7679305 - 1 - 14082017

11.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

11.2 Standard warranty terms and conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

12 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

12.1 Product fiche - Combination boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

12.2 Package fiche - boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

12.3 Package fiche - Combination heaters (boilers or heat pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

1 Safety

PN-0000367

A

B

7679305 - 1 - 14082017 5

1.1 General safety instructions

1 Safety

Danger
This boiler can be used by children aged 8 years and above and
by persons with reduced physical, sensory or mental capabilities
or lack of experience and knowledge when they have been given
supervision or instruction concerning the safe use of the device
and understand the resulting risks. Children must not be allowed
to play with the appliance. Cleaning and user maintenance must
not be carried out by children without supervision.

Danger
If you smell gas:

1. Turn off the gas supply at the meter.

2. Open windows and doors in the hazardous area.

3. Do not operate light switches.

4. Do not operate any electrical equipment.

5. Do not use a telephone in the hazardous area.

6. Extinguish any naked flame and do not smoke.

7. Warn any other occupants and vacate the premises.

8. Telephone the National Gas Emergency Service on:- 0800
111 999.

Fig.1 Taps ON and OFF

Note
If a water or gas leak occurs or is suspected, the boiler can be iso

1

lated at the inlet valves by turning their taps through 90° (

/4 turn)

downwards.

A ON
B OFF

For advice please contact your Installer, Annual Service Provider
or Baxi Customer Support - The Service Division of Baxi. You can
contact Baxi Customer Support on telephone number 0344 871

1545.
When contacting Baxi Customer Support it will be useful to have
the "Benchmark Checklist " at the back of the Installation & Serv
ice Manual to hand as it includes details relevant to the boiler and
installation.

Warning
Do not touch flue/chimney pipes. Depending on the settings of the
appliance, the temperature of flue/chimney pipes may exceed
60 °C.
Do not touch radiators for long periods. Depending on the settings
of the appliance, the temperature of radiators may reach 85 °C.
Take precautions with domestic hot water. Depending on the set
tings of the appliance, domestic hot water temperature may reach
65 °C.

Caution
Do not neglect to service the appliance. Contact a qualified pro
fessional or take out a maintenance contract for the annual servic
ing of the appliance.

1 Safety

6 7679305 - 1 - 14082017

1.2 Recommendations

Caution

Only qualified professionals are authorised to work on the boiler
and the installation.
The appliance has an integral frost protection mode as long as
there is power to the boiler.

Important

Regularly check the water pressure in the system (recommen
ded pressure is 1.5 bar).
Keep the appliance accessible at all times.
Do not remove or cover the user information and serial number
labels affixed to the boiler control flap. They must remain legible
throughout the lifetime of the boiler.

1.2.1

Baxi Heating UK Ltd is a licensed member of the Benchmark Scheme
which aims to improve the standards of installation and commissioning of
domestic heating and hot water systems in the UK and to encourage regu
lar servicing to optimise safety, efficiency and performance.

Benchmark is managed and promoted by Heating and Hotwater Industry
Council. For more information visit www.centralheating.co.uk

1.2.2

Please ensure that the installer has fully completed the Benchmark Check
list on the inside back pages of the installation instructions supplied with
the product and that you have signed it to say that you have received a full
and clear explanation of its operation. The installer is legally required to
complete a commissioning checklist as a means of complying with the ap
propriate Building Regulations (England and Wales).

All installations must be notified, by the installer, to Local Area Building
Control either directly or through a Competent Persons Scheme. A Build
ing Regulations Compliance Certificate will then be issued to the customer
who should, on receipt, write the Notification Number on the Benchmark
Checklist.

This product should be serviced annually to optimise its safety, efficiency
and performance. The service engineer should complete the relevant sec
tion of the Benchmark Service Record in the Installation & Service manual
after each service.

The completed Benchmark Checklist & proof of annual servicing (where
applicable) will be required in the event of any warranty work.

The Benchmark Scheme

Benchmark Commissioning Checklist

1.3

Liabilities

1.3.1 User's liability

To guarantee optimum operation of the system, you must abide by the fol
lowing instructions:

Read and follow the instructions given in the manuals provided with the
appliance.
Call on a qualified professional to carry out installation and initial com
missioning.
Get your installer to explain your installation to you.
Have the required inspections and maintenance carried out by a quali
fied installer.
Keep the instruction manuals in good condition close to the appliance.

1 Safety

7679305 - 1 - 14082017 7

1.3.2 Installer's liability

The installer is responsible for the installation and initial commissioning of
the appliance. The installer must observe the following instructions:

Read and follow the instructions given in the manuals provided with the
appliance.
Install the appliance in compliance with prevailing legislation and stand
ards.
Carry out initial commissioning and any checks necessary.
Explain the installation to the user.
If maintenance is necessary, warn the user of the obligation to check the
appliance and keep it in good working order.
Give all the instruction manuals to the user.

1.3.3 Manufacturer's liability

Our products are manufactured in compliance with the requirements of the
various Directives applicable. They are therefore delivered with the
marking and any documents necessary. In the interests of the quality of
our products, we strive constantly to improve them. We therefore reserve
the right to modify the specifications given in this document.

Our liability as manufacturer may not be invoked in the following cases:

Failure to abide by the instructions on installing the appliance.
Failure to abide by the instructions on using the appliance.
Faulty or insufficient maintenance of the appliance.

2 About this manual

8 7679305 - 1 - 14082017

2 About this manual

2.1 General

Warning
Installation, repair and maintenance must only be carried out only
by a competent person.

All Gas Safe registered engineers carry an ID card with their licence num
ber and a photograph. You can check your engineer is registered by tele
phoning 0800 408 5500 or online at www.gassaferegister.co.uk

This manual is intended for the user of the Baxi Combi boiler. If the appli
ance is sold or transferred, or if the owner moves leaving the appliance
behind you should ensure that the manual is kept with the appliance for
consultation by the new owner and their installer.

The appliance is designed as a boiler for use in residential domestic envi
ronments on a governed meter supply only. The selection of this boiler is
entirely at the owner’s risk. If the appliance is used for purposes other than
or in excess of these specifications, the manufacturer will not accept any
liability for resulting loss, damage or injury.

The manufacturer will not accept any liability whatsoever for loss, damage
or injury arising as a result of failure to observe the instructions for use,
maintenance and installation of the appliance.

2.2 Additional documentation

2.3 Symbols used

Various timers, external controls, etc. are available as optional extras. Full
details are contained in the relevant sales literature.

2.3.1 Symbols used in the manual

This manual uses various danger levels to draw attention to special in
structions. We do this to improve user safety, to prevent problems and to
guarantee correct operation of the appliance.

Danger
Risk of dangerous situations that may result in serious personal
injury.

Danger of electric shock
Risk of electric shock.

Warning
Risk of dangerous situations that may result in minor personal in
jury.

Caution
Risk of material damage.

Important
Please note: important information.

See
Reference to other manuals or pages in this manual.

2.4

Abbreviations/glossary

CH Central heating

DHW Domestic hot water

7679305 - 1 - 14082017 9

PCU PCB for managing burner operation
Pnc Condensing output
SU Safety PCB

2 About this manual

3 Technical specifications

10 7679305 - 1 - 14082017

3 Technical specifications

3.1 Homologations

3.1.1 Certifications

Tab.1 Certifications

CE certificate number

NOx class 5

Boiler type C13, C

3.2

Technical data

33

3.2.1 Technical information

Tab.2 General

Baxi Combi 624 630

Gas council numbers 47 077 28 47 077 29

Tab.3 Central heating circuit specifications

Baxi Combi 624 630

Maximum pressure bar 3 3

Minimum pressure bar 0.5 0.5

Central heating temperature adjustment °C 25/80 ± 5° 25/80 ± 5°

Tab.4 Domestic hot water circuit specifications

Baxi Combi 624 630

Maximum pressure bar 8 8

Dynamic minimum pressure bar 0.5 0.5

Minimum working water flow rate l/min 2.0 2.0

Domestic hot water temperature range adjust
ment

Specific flow rate (D) l/min 10 12.5

Important
Where low flow taps or fittings are intended to be used in the DHW system connected, it is strongly
recommended that the DHW flow rate DOES NOT fall below 2.5 l/min. This will ensure reliable op
eration of the DHW function.

Tab.5 Electrical specifications

Baxi Combi 624 630

Nominal electrical power supply voltage V 230 230

Nominal electrical power supply frequency Hz 50 50

Nominal power consumption when firing W 100 100

External fuse rating Amp 3 3

°C 35/60 ± 5° 35/60 ± 5°

Tab.6 Other specifications

PN-0000605

700

285

390

5

5

178

200

450

5

1

2

3

4

5

6

7

8

9

11

10

7679305 - 1 - 14082017 11

Baxi Combi 624 630

3 Technical specifications

Degree of protection against humidity (EN

IP IPX5D IPX5D

60529)

Boiler lift weight (dry) kg 30.16 30.16

Dimensions (height/width/depth) mm H 700/W 390/D 285 H 700/W 390/D 285

Clearances (above/below casing)
front (for servicing)/(in operation)
side (left hand/right hand)

mm
mm
mm

178 / 200
450 / 5
5 / 5

178 / 200
450 / 5
5 / 5

These are MINIMUM recommended dimensions. Greater clearance will aid installation and maintenance.

Important
All data in this section are nominal values and subject to normal
production tolerances.

3.2.2 Dimensions and connections/clearances

Fig.2

Dimensions and connections / clearances

1

Condensate trap sump

2

Condensate drain

3

Heating circuit water flow

4

Hot water outlet

5

Gas inlet

6

Pressure relief pipe

7

Cold water inlet

8

Heating circuit water return

9

Pump drain point

10

Boiler drain point on flow isolation tap

11

Cable entry points

The clearances shown in the diagram are minimum requirements to allow
for case removal, spanner access and air movement. These should be ob
served at all times and kept clear of obstructions.