biasi M96.24SM/C, M96.28SM/C, M96.28SR/C User guide

Wall hung, fan flue, room sealed, high efficiency gas boiler

User manual and
Installation instructions

RIVA COMPACT HE

Models

M96.24SM/C
M96.28SM/C
M96.28SR/C

This product has an energy rating B on a scale of A to G
For more information see www.boilers.org.uk
This is a certification mark

Congratulations on your choice.

RIVA COMPACT HE

They are fully electronically controlled and have electronic ignition.
The materialsthey are made of and the control systems they areequippedwithgive you safety,

a high level of comfort and energy savings to allow you to get the greatest benefit out of
independent heating.

RIVA COMPACT HE

the water vapour formed during the combustion is condensed out.
This allows a gain of useful heat that otherwise would be lost.

Remember that...

n The manual

must be read thoroughly, so that you will

---

be able to use the boiler in a safe and sen­sible way;

must be carefully kept. It may be necess-

---

ary for reference in the future.

n First lighting up

competent and responsible engineer.

n The manufacturer

disclaim all liability for any translations of

---

the present manual from which incorrect in­terpretation may occur

cannot be held responsible for non---ob-

---

servance of instructions contained in this
manual or for the consequences of any pro­cedure not specifically described.

are condensing high efficiency sealed chamber fan flue gas boilers.

allow a higher efficiency by reducing the flue gas temperature such that

valve and consequent escape of water, if not
connected correctly to the drain.

the installer has connected the conden-

---

sate outlet to a suitable drain pipe.

n On detecting the smell of gas

don’t operate any electrical switches, the

---

telephone or any device that may produce
sparks;

open the windows and doors at once to

must be carried out by

---

create a draught of air which will purge the
area;

shut off the gas cocks;

---

get the assistance of a qualified person.

---

n Do not touch the appliance

the body that are wet or damp and/or bare
feet.

n Do not block or modify

outlet and pipework

with parts of

the condensate

Using the boiler...

n Before lighting the boiler

vised to have a professionally qualified per­son check that the installation of the gas
supply

is gas--- tight;

---

is of the correct gauge for the flow to the

---

boiler;

is fitted with all the safety and control de-

---

vices required by the current Regulations.

n Ensure that

the installer has connected the pressure

---

relief valve outlet to a drain pipe. The manu­facturers are not responsible for damage
caused by opening of the pressure relief

you are ad-

n In case of structural work

ance near the exhaust duct and/or fume ex­haust devices or their attachments, turn off
the appliance. On completion of the work,
have a professionally qualified person check
their efficiency.

n Repairs

ried out only by an approved engineer, using
genuine spare parts. Thus do no more than
switching off the boiler yourself (see the in­structions).

n Your boiler

a temperature less than boiling point;

--- must be connected to a central heating
system and/or a hot water supply system,
compatible with its performance and output;

(under guarantee) must be car-

allows heating up of water to

or mainten-

--- can be used only for those purposes for

which it has been specially designed;

--- must not be touched by children or by

those unfamiliar with its operation;

--- must not be exposed to weather condi-

tions.

n During the operation

it is quite normal

that the boiler produces a white plume of
condensation vapour from the flue terminal.
This is due to the high efficiency of the ap­pliance and may be particularly evident with
low outdoor temperatures.

Safe handling of

substances

Biasi products are manufactured in accordance
with ISO 9000 and do not, and willnot, contain any
hazardous materials or substances such as as­bestos, mercury or C.F.C.’s.
The appliance packaging does not contain any
substances, which maybe considered a hazard to
health.

Combustion chamber panels

Material: mineral fibers

Known hazards --- Some people can suffer red­dening and itching of the skin. Fibre entry into the
eye will cause foreign body irritation, which can
cause severe irritation to people wearing contact
lenses. Irritation to respiratory tract.

Precautions --- Dust goggles will protect eyes.
People with a history of skin complaints may be
particularly susceptible to irritation. High dust le­vels are only likely to arise following harsh ab­rasion. In general, normal handling and use will
not present high risk, follow good hygiene prac­tices,wash hands before, touching eyes,consum­ing food, drinking or using the toilet.

First aid --- Medical attention must be sought fol­lowing eye contact or prolonged reddening of the
skin.

Thermostat / Temperature gauge

Description --- Sealed phial and capillary contain­ing liquid.

Known hazards --- irritating to skin, eyes and
throat. Vapour is harmful. Inflammable --- do not
extinguish with water.

Precautions --- Do not incinerate. Avoid contact
with broken/leaking phials. Do not purposely
puncture.

First aid medical attention must be sought follow­ing eyes/skin contact, wash with clean water.

Appliance category II
Country of destination: United Kingdom

This appliance conforms with the EEC directive 90/396 and, consequently, it hasthe rightto make use
of the brand name

Moreover, the appliance conforms with the EEC directive 87/308relative to the prevention and elimina­tion of radio disturbances.

The appliance is built to comply with the regulation now in force regarding gas appliance’s safety and
the European regulation now in force relative to safety of household and similar electricalappliances.

The manufacturer, in the continuous pocess to improve his products, reserves the right to modify the
data expressed in the present documentation at any time and without prior notice.

The present documentation is an informative support and it cannot be considered as a contract to­wards third parties.

Gas G20 20 mbar, G30 29 mbar, G31 37 mbar

2H3+

Boiler installation and commissioning tips

n The installation

a qualified person who will be responsible for
observing the current Regulations.

must be carried out by

Installing the boiler...

Do not forget to remove the transit caps

n

and plugs from the boiler connections these
are fitted to every boiler.

Keep the boiler clear of dust during in-

n

stallation and in particular do not allow any
dust or debris to enter the top of the boiler
where the flue connection is made. It is rec­ommended that you put a dust sheet over the
top of the boiler until you are ready to make
the flue connection.

Because every boiler is fired and tested

n

live at the factory, a small amount of water re­mains within the boiler. It is possible for this
water to initially cause the pump to seize. It is
therefore recommended that the pump rotor
be manually turned to free its rotation before
turning the boiler on.

Remember to release the auto air purge

n

before filling the boiler. See the instructionsto
identify the location of this device.

Do not remove the cap of the pressure

n

test points of the air switch (top left side of the
boiler).

You are strongly advised to flush out the

n

system both cold and hot in order to remove
system and installation debris.

It is also sensible to initially fire and com-

n

mission the boiler before connecting any ex­ternal controlssuch as aroom thermostat. By
this method if you have a subsequent prob­lem following the addition of an external con­trol you can eliminate the boiler from your
fault analysis.

Do not forget to range rate the boiler to

n

suit the system requirements. This pro­cedure is covered in the commissioning sec­tion of the installation manual.

If the boiler is fitted with a digital pro-

n

grammer, when setting the times for auto­matic operation, remember that for every
“ON” time there must be an “OFF” time to fol­low and that on every occasion you enter a
time you must also indicate which days that
you want the boiler to follow the timed set­tings.

Some products incorporate an anti cycl-

n

ing time delay. It is normal when first switch­ing the boiler on for the boiler to operate on
heating for a few seconds then switch off.
After 3---4 minutes has elapsed the boiler will
then re ignite and operate perfectly normally.
The ignition delay cycle does not prevent
normal operation of the boiler to provide
d.h.w.

If you are in any doubts as to the installa-

n

tion or operation of the boiler please read the
instruction manuals thoroughly and then if
necessary contact Biasi UK for advice and
assistance.

Please remember that if you are in any doubt about the installation of this product you can contact our
Technical Helpline on tel. [phone]

TABLE OF CONTENTS

1 Appliance description 2. . . . . . . . . .

1.1 Overview 2. . . . . . . . . . . . . . . . . . . . . .

1.2 Control panel 2. . . . . . . . . . . . . . . . . .

1.3 Isolation valves 2. . . . . . . . . . . . . . . . .

1.4 Technical data 2. . . . . . . . . . . . . . . . .

1.5 Operation lights 3. . . . . . . . . . . . . . . .

2 Instructions for use 4. . . . . . . . . . . .

2.1 Warnings 4. . . . . . . . . . . . . . . . . . . . . .

2.2 Refilling procedure 4. . . . . . . . . . . . . .

2.3 Ignition 5. . . . . . . . . . . . . . . . . . . . . . . .

4 Technical information 12. . . . . . . . . .

4.1 Overview 12. . . . . . . . . . . . . . . . . . . . . .

4.2 Main diagram (combi) 13. . . . . . . . . . .

4.3 Main diagram (c.h. only) 14. . . . . . . . .

4.4 Hydraulic specifications 15. . . . . . . . .

4.5 Expansion vessel 15. . . . . . . . . . . . . . .

4.6 Technical data M96.24SM/... 16. . . . . .

4.7 Technical data

M96.28SM/... M96.28SR/... 18. . . . . . .

5 General requirements 20. . . . . . . . . .

5.1 Related documents 20. . . . . . . . . . . . .

5.2 Location of appliance 20. . . . . . . . . . .

5.3 Flue system 20. . . . . . . . . . . . . . . . . . . .

5.4 Gas supply 21. . . . . . . . . . . . . . . . . . . .

5.5 Air supply 21. . . . . . . . . . . . . . . . . . . . .

5.6 Ventilation 21. . . . . . . . . . . . . . . . . . . . .

5.7 Condensate drain 21. . . . . . . . . . . . . .

5.8 Water circulation (c.h.) 21. . . . . . . . . . .

5.9 Domestic water 22. . . . . . . . . . . . . . . . .

5.10 Water treatment 22. . . . . . . . . . . . . . . .

5.11 Electrical supply 23. . . . . . . . . . . . . . . .

6 Installation 24. . . . . . . . . . . . . . . . . . . .

6.1 Warnings 24. . . . . . . . . . . . . . . . . . . . . .

6.2 Precautions for installation 24. . . . . . .

2.4 C.h. circuit temperature 5. . . . . . . . . .

2.5 D.h.w. temperature (combi) 6. . . . . .

2.6 Extinguishing 6. . . . . . . . . . . . . . . . . .

2.7 Built in time switch 7. . . . . . . . . . . . . .

3 Useful advice 10. . . . . . . . . . . . . . . . .

3.1 Central heating 10. . . . . . . . . . . . . . . . .

3.2 Frost protection 10. . . . . . . . . . . . . . . .

3.3 Periodic maintenance 10. . . . . . . . . . .

3.4 External cleaning 10. . . . . . . . . . . . . . .

3.5 Operational faults 10. . . . . . . . . . . . . . .

6.3 Installing the bracket 24. . . . . . . . . . . .

6.4 Overall dimensions 25. . . . . . . . . . . . .

6.5 Joints 25. . . . . . . . . . . . . . . . . . . . . . . . .

6.6 Mounting the boiler 25. . . . . . . . . . . . .

6.7 Fitting the flue system 26. . . . . . . . . . .

6.8 Choice of flue 26. . . . . . . . . . . . . . . . . .

6.9 Electrical connections 27. . . . . . . . . . .

6.10 External frost protection 29. . . . . . . . .

6.11 Connecting a M96.28SR/...

system boiler to a cylinder 29. . . . . . .

7 Commissioning 31. . . . . . . . . . . . . . .

7.1 Electrical installation 31. . . . . . . . . . . .

7.2 Gas supply installation 31. . . . . . . . . .

7.3 Filling the d.h.w. system 31. . . . . . . . .

7.4 Initial filling of the system 31. . . . . . . .

7.5 Condensate pipe and traps 32. . . . . .

7.6 Lighting the boiler 32. . . . . . . . . . . . . .

7.7 Checking the gas pressure

at the burner 32. . . . . . . . . . . . . . . . . . .

7.8 Adjusting the burner ignition 33. . . . .

7.9 Adjustment of useful c.h. output 34. .

7.10 Checking the ignition device 35. . . . .

7.11 Checking the flue system 35. . . . . . . .

7.12 Checking the condensate drain pipe 35

7.13 Instructing the user 35. . . . . . . . . . . . .

USE

INSTALLATIONMAINTENANCE

8 Gas conversion 36. . . . . . . . . . . . . . .

8.1 Warnings 36. . . . . . . . . . . . . . . . . . . . . .

8.2 Procedures 36. . . . . . . . . . . . . . . . . . . .

9 Maintenance 37. . . . . . . . . . . . . . . . . .

9.1 Warnings 37. . . . . . . . . . . . . . . . . . . . . .

9.2 Dismantling the external panels 37. . .

9.3 Emptying the d.h.w. system (combi) 37

9.4 Emptying the c.h. system 37. . . . . . . .

Abbreviations used in the manual
C.h. = Central heating
D.h.w. = Domestic hot water
D.c.w. = Domestic cold water

9.5 Combustion analysis check 38. . . . . .

9.6 Cleaning the primary heat exchanger 38

9.7 Checking the pressurisation

in the expansion vessel 38. . . . . . . . . .

9.8 Cleaning the burner 38. . . . . . . . . . . . .

9.9 Checking the flue 38. . . . . . . . . . . . . . .

9.10 Drain pipe inspection 38. . . . . . . . . . . .

9.11 Visual inspection of appliance 38. . . .

9.12 Gas pressures and soundness 38. . .

1

1 APPLIANCE DESCRIPTION

*notonM96.28SR/...boile

r

1.1 Overview

USE

Fig. 1.1

1 Case front panel

2 Control panel

3 Control panel cover

1.2 Control panel

4 C.h. circuit temperature and pressure gauge

5 Time switch (c.h. control) *

6 Lock---out signal lamp

7 Lockout reset button

8 Function selector and c.h. temp. control knob

9 D.h.w. temperature control knob *

10 Appliance operation lights

1.3 Isolation valves

1

16

15

14

13

2

3

Fig. 1.2 (bottom view of the boiler)

11 Condensate drain pipe

12 C.h. return valve

13 D.c.w. inlet valve *

14 Gas inlet valve

15 D.h.w. outlet pipe *

16 C.h. flow valve

12

11

1.4 Technical data

For detailed technical data see section 4.6 or 4.7
of this manual.

M96.24SM/...
M96.28SM/...

89 7 6 4510

M96.28SR/...

Fig. 1.3

2

Appliance description

LampOFFLampONFlashinglamp,aloneorsimultaneously

Flashinglamp,alternatewithanother

*notonM96.28SR/...boile

r

1.5 Operation lights

Three lights (10 in Fig. 1.3) give detailed indication
regarding the operation of the boiler.

The following table gives the relationship between
each of the possible light combinations and their
meaning.

USE

with an other lamp.

A short pulse every 4
seconds:
stand--- by condition
Function selector in
position.
Anti---freeze system active

1 second pulse every 2
seconds: normally
operating boiler. Function
selector in or
position

C.h. operation

D.h.w. operation *

Frost protect operation

D.h.w. operation
Excessive temperature on
primary circuit *

Faulty c.h. temperature
probe NTC

lamp.

Faulty d.h.w temperature
probe NTC *

Faulty primary circuit
(no water or absence of
flow)

Lack of burner ignition (no
ignition signal from the full
seqence ignition device)

Ignition gas pressure
adjustment

Minimum gas pressure
adjustment

3

2 INSTRUCTIONS FOR USE

2.1 Warnings

Biasi UK Ltd support the Benchmark initiat­ive. The Benchmark Log Book is located at
the back of this manual and should be com­pleted by the Installing/Commisssioning
Engineer and handed over to the User for

USE

future reference by other visiting En­gineers. Also included is the Service Inter­val Record card that should be completed
by the Service Engineer following the an­nual service maintenance of the boiler and
system.

All CORGI Registered Installers carry a
CORGI ID card, and have a registration
number. Both should be recorded in your
Benchmark Log Book. You can check your
installer is registered by calling CORGI di­rect on 01256 372300.

In order to guarantee safety and correct oper­ation, it is essential that all the tests are carried
out by a competent and responsible service
engineer before lighting up the boiler.

The tests are described in the installation in-
structions in section 7 commissioning.

Ensure that the c.h. circuit is regularly filled
with water (even if the boiler is only used for
d.h.w. supply) checking thatthe pressure indi­cated on the temperature and pressure gauge
4 is not lower than that shown in Fig. 2.2.

If the pressure reading on the pressure gauge
is belowthat shown in Fig. 2.2, then the system
willrequire topping up. A filling loop is normally
provided by the installer for this purpose.

If you are in any doubt regarding this pro­cedure you are advised to contact your In­staller or an Approved Engineer.

This appliance is provided with a built in anti--­freeze system that operates the boiler when
the temperature is below 4 ° C
Therefore, when the boiler is not lit or used in
cold weather, with consequent risk of freezing

do not switch off the boiler at the fused spur
isolation switch or close the gas inlet cock

When you do not expect to use the boiler for a
long period and the boiler is not to be used for
frost protection then follow the instructions
given in section 2.6 on page 6.

2.2 Refilling procedure

1 Isolate the boiler from the electrical supply at

the fused spur. Reconnect the filling loop as
demonstrated in Fig. 2.1.

Control valve

Double check valve

Temporary
connection

Supply pipe

(cold water inlet)

C.h. return pipe

Fig. 2.1

2 Open the valves of the filling loop and watch

the gauge until it reaches normal filling pres­sure as shown in Fig. 2.2.

Fig. 2.2

3 Close the valves and remove the filling loop.

If you experience any difficulty with the oper­ation of the boiler, switch off the boiler immedi­ately at the fused spur isolation switch and
contact your Installer or an approved Service
Engineer

Air introduced into the boiler during this filling pro­cess will vent through the automatic air purger
fitted to the boiler. You may also find it necessary
to vent air from your radiator circuit using your
radiator key, however be aware that excessive
venting will cause the pressure in the system to
drop.

Always ensure thatthe pressure gauge isset at the

.

required pressure.

Control valve

4

Normal filling
pressure

4

Instructions for use

2.3 Ignition

1 Check that the valves located in the lower part

of the boiler are open (Fig. 2.3).

Open position

Fig. 2.3

2 Turn on the electricity supply to the boiler,

switching on the fused spur isolation switch.
The appliance operation light 10 (Fig. 2.4) will
flash every 4 seconds (stand---by condition).

3 If the boileris to be used for c.h. and d.h.w posi-

tion the function selector 8 as in Fig. 2.4
(combi) or in Fig. 2.5 (c.h. only).
The appliance operation light 10 will flash
every 2 seconds (operating boiler).

810

USE

810

Fig. 2.6

2.4 C.h. circuit temperature

The output temperature of c.h. water is adjustable
from a minimum of about 38°C to a maximum of
about 85°C (Fig. 2.7), by turning the function se­lector (8).

Adjustment of c.h. output on the boiler is auto­matic. The greatest output pre --- set in the factory
can, however, be reduced in level according to
actual system requirements; this does not affect
the maximum output in d.h.w. operation.

Such adjustments must be carried out by a quali­fied person; therefore we advise you to contact
your installer or Service Agent.

Adjustment of the boiler temperature alters the
gas flow at the burner according to the thermal de­mand in the system. So it is usual to see the burner
lit at the minimum level for more or less long
periods.

Fig. 2.4

810

Fig. 2.5

4 If d.h.w. supply only is required (combi), posi-

tion the function selector 8 as in Fig. 2.6.
The appliance operation light 10 will flash
every 2 seconds (operating boiler).

Minimum

Maximum

Fig. 2.7

5

Instructions for use

Adjustment

In order to achieve optimal settings for economy
and comfort, we recommend adjusting the oper­ating temperature of the c.h. water according to
the outside temperature, positioning the knob as
follows:

USE

From 5 to 15 ° C

Between

---5 and +5 ° C

Lower than

---5 ° C

Fig. 2.8

Your qualified installer will be able to recommend
the most suitable adjustment for your system.

The temperature and pressure gauge (4, Fig. 1.3
on page 2) will allow you to check that the settem­perature is obtained.

The adjustment system integrated within the
boiler automatically controls the flow of gas to the
burner in order to keep the temperature of d.h.w.
delivered constant, between the limits of maxi­mum and minimum output.

Where the demand is at a low level or with the tem­perature set to the minimum, it is normal to see a
cycle of lighting and extinguishing of the burner
when running.

Adjustment

It is advisable to adjust the d.h.w. temperature to
a level commensurate with the demand, minimis­ing the need to mix with cold water. In this way, the
automatic control facilities will be fully exploited.

Moreover, where the amount of limescale present
in the water may be particularly great, not exceed­ing the position in
ture control knob 9 corresponding to about 50°C
(Fig. 2.10), minimises annoying incidences of
scale deposits and clogging.

Fig. 2.10

of the d.h.w. tempera-

2.5 D.h.w. temperature (combi)

The temperature of the d.h.w. leaving the boiler
can be varied from a minimum of about 35°C to a
maximum of about 55°C (Fig. 2.9), by turning the
temperature control knob 9.

Minimum

Maximum

Fig. 2.9

Adjustment of the d.h.w. temperature is complete­ly separate from that of the c.h. circuit.

9

9

Fig. 2.10

In these cases, however, it is advisable to install a
small water treatment device or softener. With
such a device you should avoid periodic descal­ing.

Consequently,the d.h.w.heat exchanger will keep
its performance consistent for a longer period of
time with resulting gas savings.

If the demand for d.h.w. is so great as to prevent
reaching a high enough temperature, have the ap­propriate output limiting valve installed by your in­staller or an Authorised Service Engineer.

2.6 Extinguishing

To turn the boiler off set the function selector 8 to
the position shown in Fig. 2.11 (combi) or
Fig. 2.12 (c.h. only).

6

Instructions for use

The appliance operation light 10 will flash every 4
seconds.

810

Fig. 2.11

810

2.7 Built in time switch (combi)

The combi boilersare equipped with a built in elec­tronic time switch (5, Fig. 1.3 on page 2) which
controls the c.h. operation.

G

BCDEF

Fig. 2.14

H

A

USE

Fig. 2.12

When you do not expect to use the boiler for a long
period:

1 Switch off the electricity supply to the boiler, by

means of the fused spur isolation switch;

2 Shut off the gas supply cock 14 and the valves

for the water circuits fitted under the boiler
(Fig. 2.13).

3 Empty the water circuits, if necessary, as

shown in the installation instructions in the sec­tion maintenance.

14

Fig. 2.13

Closed position

Display and control panel

A Mode selector switch

B Reset button

C Enter button

D Increase “+” setting button

E Decrease “--- ” setting button

F On--- off button

G Time display

H ON--- OFF display

Setting the current time

Note: with a new unit or when the reset button B
has been pressed and the selector switch A is to

the position, the time display G is flashing.

Set the mode selector switch A to the position
and press the buttons D or E until the current time
appears in the display G.

The clock starts by moving the switch A to the
AUTO position.

Setting example shown in Fig. 2.15:
Current time 16.30.

7

Instructions for use

A

A

USE

Fig. 2.15

Setting the switching time

20 memorylocations are available, corresponding
to 10 on---off sequences.

Set the mode selector switch A to theC1position.
The symbols shown in Fig. 2.16 appears in the
display.

Fig. 2.16

Press the buttons D or E to set the desired ON
time.

Press the “enter” button C to confirm the setting
and to continue programming the OFF time.

Set the OFF time as explained above for the ON
setting and confirm by pressing the “enter” button
C. Proceed in the same way for other settings.

Setting example shown in Fig. 2.17:
A --- ON time 7.45.
B --- OFF time 10.30.

Fig. 2.18

Note: when the mode selector switch A is in the

AUTO

fused spur isolationswitch, the display H indicates
only the OFF state. The other indications are
blanked.

Reading the timed settings

Set the mode selector switch A to theC1position.
The symbols shown in Fig. 2.16 appears in the

A

display.

Press the “enter” button C. Each time the button
is pressed the display showsthe details of the next
setting.

Changing or deleting the timed settings

Set the mode selector switch A to theC1position.
The symbols shown in Fig. 2.16 appears in the
display.

Press the “enter” button C until the display shows
the setting to be modified or deleted.

The time setting can be modified now by pressing
button D or E and the operation can be switched
on or off by pressing the button F.

To delete a time set press the button D or E until the
symbols shown in Fig. 2.16 appears in the time
display G.

The new settings are memorized by moving the
switch A to a different position.

position and the boiler is switched off at the

A B

Fig. 2.17

Activating the timed settings

Set the mode selector switch A to the
tion shown in Fig. 2.18.

The current time appears in the display. The ON --­OFF display H indicates the current state of oper­ation (according to the settings).

8

AUTO

posi-

Manual operation

The operation of the time switch can be forced on
or off constantly or for a timed period.

To force
set the mode selector switch A to the
tion. The symbols shown in Fig. 2.19 appears on
the display.

constantly

on or off the timer operation

TIMER

posi-

Instructions for use

Fig. 2.19

The operation can be switched permanently on or
off by pressing the button F and leaving the switch
A in the

To force
mode selector switch A in the

Set the time delay by pressing the button D or E
and the operation can be forced on or off by pres­sing the button F.

The time delay can be set within the following
ranges:

1 to 23 hours with steps of 1 hour
1 to 27 days with steps of 1 day

The time delay setting is activated by moving the
switch A to the
The ON --- OFF display H flashesindicating that the
current state of operation has been forced.

TIMER

a timed delay

position.

AUTO

on or off operation, set the

TIMER

position.

position.

To delete the timed delay setting, setthe mode se­lector switch A in the
button D or E until the symbols shown in Fig. 2.19
appears in the display and then set the mode se­lector switch A to the

Setting example shown in Fig. 2.20:
forced ON state for 4 hours.

Fig. 2.20

Resetting

To completely reset the timer, press the reset but­ton with a pointed object (pencil).

CAUTION: pushing the reset button will complete­ly erase the settings as well as all the data, includ­ing the current time.

TIMER

AUTO

position, press the

position

USE

9

3 USEFUL ADVICE

3.1 Central heating

---

general check of the appliance’s operation.

For reasonably economical service install a room
thermostat.

Never shut off the radiator in the area where the
room thermostat is installed.

USE

If a radiator (or a convector) does not heat up,
check that no air is present in it and that its valve
is open.

If the ambient temperature is too high, do not alter
the radiator valves. Reduce the central heating
temperature instead by means of the room ther­mostat and the function selector (8 in Fig. 3.1).

8

Fig. 3.1

3.4 External cleaning

Before carrying out any cleaning, disconnect the
appliance from the electrical mains, using the
fused spur isolation switch fitted adjacent to the
appliance.

To clean the external panels, use a cloth soaked in
soapy water. Do not use solvents, abrasive powd­ers or sponges.

Do not carry out cleaning of the appliance and/or
its parts with readily flammable substances (for
example petrol, alcohols, naphtha, etc.).

3.5 Operational faults

If the lock--- out signal lamp comes on

this indicates that the safety lock--- out 6 (Fig. 3.2)
has stopped the boiler

To re --- start the boiler, it is necessary to press the
boiler reset button 7 (Fig. 3.2).

3.2 Frost protection

This appliance is provided with a built in anti--­freeze system that operates the boiler when the
temperature is below 4 ° C
Therefore, when the boiler is not lit and used in
cold weather, with consequent risk of freezing

not switch off the boiler at the fused spur isola­tion switch or close the gas inlet cock

.

do

3.3 Periodic maintenance

For efficient and continuous operation of the
boiler, it is advisable to arrange maintenance and
cleaning by an Authorised Service Centre En­gineer, at least once a year.

During the service, the most important compo­nents of the boiler will be inspected and cleaned.
This service can be part of a maintenance con­tract.

In particular, you are advised to have the following
checks carried out:

---

primary heat exchanger;

---

domestic hot water heat exchanger;

---

burner;

---

exhaust fume duct and flue;

---

pressurisation of the expansion tank;

---

filling up of the central heating circuit;

---

bleeding of air from the central heatingsystem;

6

7

Fig. 3.2

For the first lighting up and following maintenance
procedures for the gas supply, it may be necess­ary to repeat the resetting operation several times
so as to remove the air present in the pipework.

Safety lock--- out may occour even in case of an
blockage of the condensate drainage (e.g.
plugged drain pipe).

It is advisable to check the condensate drainage
pipe and traps for cleaness.

In case of persistent lock--- out call a competent
and responsible service engineer.

If noises due to air bubbles are heard during
operation...

you should check that the pressure on the tem­perature and pressure gauge (Fig. 2.2 on page 4)
is not below the correct setting.
If required, top up the system correctly, as de­scribed in the section 2.2 of this manual.
Bleed any air present in the radiators, if necessary.

10

Useful advice

If the pressure on the temperature and pres­sure gauge (4 on page 2) has gone down...

it is necessary to top up the appliance with water
again, so as to raise the pressure to an adequate
levelas described in the section 2.2 of this manual.

If topping up with water has to be done very fre­quently, have the system checked for leaks.

If water comes out of the pressure relief valve

Check on the temperature and pressure gauge (4
on page 2) that the pressure in the central heating
circuit is not close to 3 bars. In this case, tempera­ture rise in the circuit can cause the pressure relief
valve to open.

So that this does not happen and to decrease the
pressure to a normal value, it is advisable to vent
some of the water in the appliance through the
bleed valves present in the radiators.

If in time, a reduction in domestic hot water
supply is observed...

The likely causes may be impurities caught in the
domestic hot water flow switch filter or limescale
deposited in the domestic hot water heat ex­changer. It is advisable to have the appliance
cleaned out by an Authorised Service Centre En­gineer.

If water should occasionally leak from the
boiler...

shut off the valves positioned under the boiler
(Fig. 2.13 on page 7) and call an Authorised Ser­vice Centre Engineer.

If the left appliance operation light 10 (Fig. 3.3)
flashes very quickly the boiler is detecting a
fault.

10

Fig. 3.3

In this case or in case of problems other than
those mentioned here, switch off the boiler, as
described in section 2.6 on page 6 and call a
competent and responsible service engineer.

USE

11

4 TECHNICAL INFORMATION

4.1 Overview

32

31

30

INSTALLATION

29

28

27

26
25

24

23

Fig. 4.1

11 Condensate drain pipe
12 C.h. return valve
13 Domestic cold water inlet valve
14 Gas inlet valve

33

34 37

35

20

2122

19

36

17

18

15 D.h.w. outlet pipe
16 C.h. flow valve
17 Condensate trap

18 Main circuit drain valve

19 Automatic air purger valve

20 Pump

21 Pump vent plug

22 Modulation gas valve

23 D.h.w. temperature probe NTC

24 Primary circuit flow switch

25 C.h. temperature probe NTC

26 Three---way diverter valve

27 Flame--- detecting electrode

28 Ignition electrodes

29 Burner

30 Combustion chamber

31 Primary heat exchanger

32 Fan

33 Air switch pressure test points

34 Flue thermostat

35 Air pressure switch

36 Co ndensing heat exchanger

37 Safety thermostat

38 D.h.w. flow switch

39 C.h. pressure relief valve

40 Modulation operator

41 Gas valve outlet pressure test point

42 Gas valve inlet pressure test point

43 D.h.w. heat exchanger

44 C.h. expansion tank

45 By --- pass valve

46 Venturi device

47 Domestic water circuit filter

48 D.h.w. flow limiter

49 Flue outlet pipe

50 Air intake pipe

12

Technical information

4.2 Main diagram (combi)

50

34

36

49

46

27

28

17

40

11

31

29

32

41

42

22

44

35

18

39

19

24

37

20

45

25

26

48

47

38

43

INSTALLATION

23

Fig. 4.2

12 131614

15

13

Technical information

4.3 Main diagram (c.h. only)

34

36

50

49

INSTALLATION

46

27

28

17

40

11

31

29

32

41

42

22

35

37

19

20

44

25

24

39

45

18

Fig. 4.3

14

12 1614

Technical information

4.4 Hydraulic specifications

kPa bar

0.6

60

50

0.5

40

0.4

0.3

30

20

0.2

0.1

10

0

0.0

0 200 400 600 800 1000 1200 1400

l/h

Fig. 4.4

The hydraulic specifications in Fig. 4.4 represent
the pressure (available head for the central heat­ing system) as a function of the flow rate.

The load loss due to the boiler has already been
subtracted.

tem component cocks, the by--- pass valve ensur­es a minimum flow of water through the primary
heat exchanger.

4.5 Expansion vessel

Note: this boiler is designed for operation only
in a sealed central heating system

The height difference between the pressure relief
valve and the highest point in the system may be
7m at most.

For greater differences, increase the pre --- load
pressure in the expansion vessel (44 on page 12)
and the system, when cold, by 0.1 bar for each
additional 1m.

Capacity l 6,0

Pre--- load pressure kPa

bar

Maximum volume of water

l 132

in the system *

Tab. 4.1

100

1,0

INSTALLATION

Output with thermostat cocks shut off

The boiler is fitted with an automatic by --- pass
valve (45 on page 12), which protects the primary
heat exchanger.

In case of excessive reduction or total blockage of
water circulation in the central heating system
owing to closure of the thermostatic valves or sys-

* Where conditions are:

---

Average maximum temperature of the system
is 80°C

---

Initial temperature when filling up the system is
10°C

For systems with volumes greater than 132 l, an
additional expansion vessel must be provided.

15

Technical information

4.6 Technical data

mod. M96.24SM/...

Heat input

Nominal kW

Minimum kW

Useful output G20

Maximum kW

Minimum kW

Maximum condensing kW

(A)

INSTALLATION

Minimum condensing kW

Useful output G30 G31

Maximum kW

Minimum kW

Maximum condensing kW

Minimum condensing kW

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

25,0

85 295

11,0

37 530

24,6

83 973

10,2

34 936

26,6

90 754

11,1

37 871

23,7

80 894

10,2

34 936

26,6

90 754

10,8

36 997

Central heating

Maximum flow temp. ° C 85

Minimum flow temp. ° C 38

Minimum return temp. ° C 30

Maximum pressure kPa

bar

Minimum pressure kPa

bar

Available head
(in 1000 l/h)

Seasonal efficiency

(B)

G20

Seasonal efficiency
G30 G31

(B)

kPa

bar

band
%

band
%

300

30

0,3

25

0,25

87,7

86,9

Domestic hot water

Maximum temperature ° C 55

Minimum temperature ° C 35

Maximum pressure kPa

bar

Minimum pressure kPa

bar

1 000

10

30

0,3

Flow rate

minimum l/min 2,5

30° rise

35° rise

40° rise

(C)

(C)

(C)

l/min 12,1

l/min 10,1

l/min 8,7

3

B

B

Gas supply pressures

Gas Natural

G20

Norm. Pa

mbar

Max Pa

mbar

Min. Pa

mbar

2 000

2 500

1 700

20

25

17

Butane

G30

2 900

29

3 500

35

2 000

20

Propane

G31

3 700

4 500

2 500

1 mbar approximately equals 10 mm H2O

(A)

referred to the net calorific value at 15 ° C and 1013,25 mbar

G 20 = 34,02 MJ/m3,G 30 = 45,6 MJ/kg, G 31 = 46,4 MJ/kg

(B)

The value is used in the UK Government’s Standard Assessment Procedure (SAP) for energy rating

of dwellings. The test data from which it has been calculated have been certified by a notified body.

(C)

Values subject to tolerance

16

37

45

25

Technical information

Gas pressures at the burner

Gas Natural

G20

Max. Pa

mbar

Min. Pa

mbar

Ignition Pa

mbar

1080

10,8

150

1,5

600

6,0

Butane

G30

2800

28,0

550

5,5

1200

12,0

Propane

G31

3550

35,5

770

7,7

1300

13,0

1 mbar approximately equals 10 mm H2O

Gas rate

Gas Natural

G20

m3/h

Butane

G30

kg/h

Propane

G31

kg/h

Max. 2,65 1,97 1,94

Min. 1,16 0,87 0,85

Flue design

Flue pipe diameter

Coaxial mm 60/100

Twin split pipes mm 80

Roof mm 80/125

Nominal heat flow rate

(A)(D)

Exhaust temperature

Smoke production

(D)

(D)

kW 25,0

° C 90

kg/h 68

Flue gas figures

Nominal heat input

(A)(D)

kW 25,0

CO2content % 6,4

O2content % 11,1

CO content ppm 50

Exhaust temperature

(D)

° C 90

INSTALLATION

Injectors

Natural G20 130

Butane G30 75

Propane G31 75

Electrical Data

Voltage V~ 230

Frequency Hz 50

Power consumption W 140

Protection degree IPX4D

External fuse rating A 3

Internal fuse rating A 1,6 T

Other specifications

Height mm 803

Width mm 400

Depth mm 350

Weight (dry) kg 42,5

Water volume in the boiler

l (kg) 2,1

(up to 1 bar)

(D)

Values refer to tests with a 1 m chimney working at the nominal heat input

17

Technical information

4.7 Technical data mod.

M96.28SM/... M96.28SR/...

Heat input

Nominal kW

Minimum kW

Useful output G20

Maximum kW

Minimum kW

Maximum condensing kW

(A)

INSTALLATION

Minimum condensing kW

Useful output G30 G31

Maximum kW

Minimum kW

Maximum condensing kW

Minimum condensing kW

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

BTU/h

29,0

98 942

13,0

44 353

28,3

96 488

12,1

41 284

30,7

104 602

13,2

44 965

27,4

93 599

12,1

41 284

30,7

104 602

12,9

44 016

Central heating

Maximum flow temp. ° C 85

Minimum flow temp. ° C 38

Minimum return temp. ° C 30

Maximum pressure kPa

bar

Minimum pressure kPa

bar

Available head
(in 1000 l/h)

Seasonal efficiency

(B)

G20

Seasonal efficiency
G30 G31

(B)

kPa

bar

band
%

band
%

300

30

0,3

25

0,25

87,5

87,0

Domestic hot water (M96.28SM/... only)

Maximum temperature ° C 55

Minimum temperature ° C 35

Maximum pressure kPa

bar

Minimum pressure kPa

bar

1 000

10

30

0,3

Flow rate

minimum l/min 2,5

30° rise

35° rise

40° rise

(C)

(C)

(C)

l/min 14,0

l/min 11,7

l/min 10,1

3

B

B

Gas supply pressures

Gas Natural

G20

Norm. Pa

mbar

Max Pa

mbar

Min. Pa

mbar

2 000

2 500

1 700

20

25

17

Butane

G30

2 900

29

3 500

35

2 000

20

Propane

G31

3 700

4 500

2 500

1 mbar approximately equals 10 mm H2O

(A)

referred to the net calorific value at 15 ° C and 1013,25 mbar

G 20 = 34,02 MJ/m3,G 30 = 45,6 MJ/kg, G 31 = 46,4 MJ/kg

(B)

The value is used in the UK Government’s Standard Assessment Procedure (SAP) for energy rating

of dwellings. The test data from which it has been calculated have been certified by a notified body.

(C)

Values subject to tolerance

18

37

45

25

Technical information

Gas pressures at the burner

Gas Natural

G20

Max. Pa

mbar

Min. Pa

mbar

Ignition Pa

mbar

1000

10,0

160

1,6

600

6,0

Butane

G30

2800

28,0

590

5,9

1200

12,0

Propane

G31

3600

36,0

770

7,7

1300

13,0

1 mbar approximately equals 10 mm H2O

Gas rate

Gas Natural

G20

m3/h

Butane

G30

kg/h

Propane

G31

kg/h

Max. 3,07 2,29 2,25

Min. 1,28 1,03 1,01

Flue design

Flue pipe diameter

Coaxial mm 60/100

Twin split pipes mm 80

Roof mm 80/125

Nominal heat flow rate

(A)(D)

Exhaust temperature

Smoke production

(D)

(D)

kW 29,0

° C 90

kg/h 76

Flue gas figures

Nominal heat input

(A)(D)

kW 29,0

CO2content % 6,8

O2content % 10,7

CO content ppm 75

Exhaust temperature

(D)

° C 90

INSTALLATION

Injectors

Natural G20 130

Butane G30 75

Propane G31 75

Electrical Data

Voltage V~ 230

Frequency Hz 50

Power consumption W 160

Protection degree IPX4D

External fuse rating A 3

Internal fuse rating A 1,6 T

Other specifications

Height mm 803

Width mm 400

Depth mm 350

Weight (dry) kg 44,5

Water volume in the boiler

l (kg) 2,2

(up to 1 bar)

(D)

Values refer to tests with a 1 m chimney working at the nominal heat input

19

5 GENERAL REQUIREMENTS

Biasi UK Ltd support the Benchmark initiative.
The Benchmark Log Bookis located at the back
of this manual and should be completed by the
Installing/Commisssioning Engineer and
handed over to the User for future reference by
other visiting Engineers. Also included is the
Service Interval Record card that should be
completed by the Service Engineer following
the annual service maintenance of the boiler
and system.

This appliance must be installed by a compet­ent person in accordance with the Gas Safety
(installation & Use) Regulations.

5.1 Related documents

The installation of this appliance must be in ac­cordance with the relevant requirements of the

INSTALLATION

current Gas Safety (Installation & Use) Regula­tions, the Local Building Regulations, the current
I.E.E. Wiring Regulations, the Regulations and
by--- laws of the local water undertaking, and in
Scotland, in accordance with the Building Stan­dards (Scotland) Regulation. Health and safety
document n° 635 ”Electricity at work regs.”.

It should also be in accordance with the British
Standard Codes of Practice:

5.3 Flue system

The provision forsatisfactory flue terminationmust
be made as described in BS 5440 part 1.

The appliance mustbe installed so that the flue ter­minal is exposed to external air.

It must not be installed so that the terminal dis­charges into an other room or space as an out­house or lean---to. It is important that the position
of the terminal allows a free passage of air across
at all times.

The terminalshould belocated with due regard for
the damage or discoloration that might occur to
building products in the vicinity.

In cold and/or humid weather water vapour may
condense on leaving the flue terminal; the effect of
such ”steaming” must be considered.

Pluming may easily occur at the terminal. Where
possible, terminal position which could cause a
nuisance should be avoided.

The minimum acceptable spacing from the ter­minal to obstructions and ventilation openings are
specified in Fig. 5.1.

5.2 Location of appliance

The appliance may be installed in any room or in­ternal space, although particular attention is
drawn to the requirementsof the current I.E.E. Wir­ing Regulations, and in Scotland, the electrical
provisions of the Building Regulations applicable
in Scotland, with respect to the installation of the
combined appliance in a room containing a bath
or shower.

Where a room--- sealed appliance is installed in
a room containing a bath or shower, any electri­cal switch or appliance control, utilising mains
electricity should be so situated that it cannot
be touched by a person using the bath or
shower.

The location must permit the provision of an ad­equate flue and termination.

For unusual locations special procedures may be
necessary and BS 6798 gives detailed guidance
on this aspect.

A compartment used to enclose the appliance
must be designed specifically for this purpose.

This appliance is not suitable for external installa­tion.

M

HI

BC

F

D

J

A

O

N

E

F

G

KL

G

Fig. 5.1

Terminal position mm

A Directly below a window or other opening 300. . . .

B Below gutters, soil pipes or drain pipes 75. . . . . .

C Below eaves 200. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D Below balconies or car port roof 650. . . . . . . . . . . .

E From vertical drain pipes and soil pipes 75. . . . . .

F From internal or external corners 300. . . . . . . . . . . .

G Above ground or balcony level 300. . . . . . . . . . . . .

H From a surface facing a terminal 600. . . . . . . . . . . .

I From a terminal facing a terminal 1 200. . . . . . . . . . .

J From an opening in the car port.

(e.g. door, window) into dwelling 1 200. . . . . . . . .

K Vertically from a terminal in the same wall 1 500. .
L Horizontally from a terminal in the same wall 300. .

Table follows in next page

M Above the roof pitch with roof slope less

20

rev. 17.09.93

General requirements

than or equal to 30° 600. . . . . . . . . . . . . . . . . . . . . .

Above the roof pitch with roof slope

more than 30° 1 000. . . . . . . . . . . . . . . . . . . . . . . . .

N From wall face 600. . . . . . . . . . . . . . . . . . . . . . . . . . .

O From an opening 300. . . . . . . . . . . . . . . . . . . . . . . . .

* specific manufacturer requirements

5.4 Gas supply

The Gas meter is connected to the service pipe by
the local gas region or a local gas region contrac­tor.

If the gas supply for the boiler serves other
appliances ensure that an adequate supply is
available both to the boiler and the other
appliance when they are in use at the same time.

Pipework must be of adequate size. Pipes of a
smallersize than the boiler inlet connection should
not be used.

Installation pipes should be fitted in accordance
with BS 6891 and the complete installation should
be tested for soundness.

The length of the condensate pipe should be kept
at minimum.

To avoid condensate being trapped:

---

the drainpipe should be run with a fallof atleast

2.5° (45 mm/m) away from the boiler;

---

the number of bends and joints should be kept
at minimum;

---

the drainpipe should be adequately fixed to
pevent pipe sagging.

If a part of the drainpipe runs externally this part
should pe kept as short aspossible and protected
to reduce the risk of freezing.

Condensate drain

INSTALLATION

5.5 Air supply

The room in which the boiler is installed does not
require a purpose provided air vent.

5.6 Ventilation

If installed in a cupboard or compartment, it is not
necessary to provide additional ventilation for
cooling for this particular product. However con­sideration must be given to clearance require­ments for maintenance (see section 6.2) and
under no circumstances must storedarticles be al­lowed to come into contact with the boiler or flue
pipe.

5.7 Condensate drain

Ensure that the condensate discharge complies
with the national or local regulations in force.

The condensate pipe must be fitted in accordance
with Building Regulations.

Drainpipe material should be resistant to acid as
the condensate is slightly acid with a pH less than

6.5.

The boiler includes a trap (17 on page 12) that pre­vents the combustion products entering the drain,
however an additional trap with a sealof at least 75
mm and an air break between thetraps is required
(Fig. 5.2).

Fig. 5.2

5.8 Water circulation (c.h.)

Detailed recommendations are given in BS 6798
and BS 5449; the following notes are given for
general guidance.

Pipework

The return temperature must not be lower of
30 ° C.

Copper tubing to BSEN 1057is recommended for
water pipes. Jointing should be either with capil­lary soldered or with compression fittings.

Where possible pipes should have a gradient to
ensure air is carried naturally to air release points
and water flows naturally to drain taps.

The appliance has a built--- in automatic air release
valve, it should be ensured as far as possible that
the appliance heat exchanger is not a natural col­lecting point for air.

Except where providing useful heat, pipes should
be insulated to prevent heat loss and to avoid
freezing.

Particular attention should be paid to pipes pas­sing through ventilated spaces in roofs and under
floors.

By--- pass

rev. 17.09.93

21

General requirements

The appliance includes an automatic by--- pass
valve which protects the main heat exchanger in
case of reduced or interrupted water circulation
through the heating system due to the closing of
thermostatic valvesor cock--- type valves within the
system.

The by--- pass is calibrated to assure a minimum
flow of 500--- 600 lts/hr through the main heat ex­changer.

If you are installing a system that includes thermo­static radiator valves (TRV) and/or small bore
(8--- 10 mm) it may be necessary to fit an external
by--- pass to facilitate correct operation of the
boiler.

Air release points

These must be fitted atall high pointswhere air will
natural collect and must be sited to facilitate com­plete filling of the system.

INSTALLATION

Expansion vessel

The appliance has an integral sealed expansion
vessel to accommodate the increase of water vol­ume when the system is heated.

Refer to Tab. 4.1 on page 15 for its technical data.
If the heating circuit has an unusually high water

content, calculate the total expansion and add an
additional sealed expansion vessel with adequate
capacity.

Mains water feed: central heating

There must be no direct connection to the mains
water supply even through a non return valve,
without the approval of the Local Water Authority.

Mains water feed: hot water supply

The domestic section of the boiler is designed to
withstand an internal domestic water pressure of
10 bar. Where it is likely that the mains domestic
water pressure may exceed 5 bar, it is possible
due to internal “water hammer” effects that the
pressure within the domestic system can increase
to a level in excess of the 10 bar limit.

In these circumstances it is therefore recom­mended that a 3 bar pressure reducing valve be
fitted to the incoming mains water supply and a
mini expansion vessel installed on the domestic
circuit.

These devices will protect the boiler and the do­mestic system from damage due to excessive do­mestic water pressure.

Filling

A method for initially filling the system and replac­ing water lost during servicing must be provided
and it must comply with local water authority regu­lations.

The correct method is shown in Fig. 5.3.

The temporary connection must be removed
immediately after filling.

Control valve

Double check valve

Temporary
connection

Supply pipe

(cold water inlet)

C.h. return pipe

Control valve

Fig. 5.3

The installer should ensure that no leaks exist
either inside the boiler or on the system as fre­quent filling of the system could cause premature
scaling of the heat exchanger.

5.9 Domestic water

The domestic water installation must be in accord­ance with the relevant recommendations of BS

5546. Copper tubing to BS EN 1057 is recom­mended for water carrying pipework and must be
use for pipework carrying potable water.

5.10 Water treatment

Central heating circuit

Where a new boiler is fitted to a new system with
either plastic or copper pipes, it is important the
system is fully flushed, on completion, to ensure
flux residues, swarfs, oils and other installation de­bris is removed.

Where a new boiler is fitted to an existing system,
it is important the debris from the existing system
is fully removed in order to ensure the efficiency of
the new appliance is maintained.

Detailson flushing procedure are given in the sec­tion 7.4 of this manual.

Domestic hot water circuit (scale protection)

In areas where the water is ’hard’ (i.e. more than
200 ppm total hardness as defined by BS 7593:

22

rev. 17.09.93

General requirements

1993 Table 2) it is recommended that a proprietary
scale--- reducing device is fitted into the boiler cold
supply, within the requirements of the local water
company.

5.11 Electrical supply

Warning, this appliance must be earthed.

External wiring to the appliance must be carried
out by a competent person and be in accordance
with the current I.E.E. Regulations and any local
regulations which apply.

The boiler is supplied for connection to a 230 V~
50 Hz supply. The supply must be fused at 3A.

The method of connection to the electricity supply
must facilitate complete electrical isolation of the
appliance by the use of a fused double pole isola­tor having a contact separation of at least 3 mm
between poles or alternatively, by the use of a 3A
fused three pin plug and unswitched shuttered
socket outlet both complying with BS 1363.

The point of connection to the electricity supply
must be readily accessible and adjacent to the
appliance except were the appliance is installed in
a bathroom this must then be sited outside the
bathroom.

INSTALLATION

rev. 17.09.93

23

6 INSTALLATION

6.1 Warnings

The use of gas appliances is subject to
statutory control; it is essential to observe
the current regulations and laws in force
(see also chapter 5).

The appliance must discharge combustion
products directly outside or into a suitable ex­haust duct designed for this purpose.

Combustion products must be discharged
using original flue kits only, since they are inte­gral parts of the boiler.

For LPG, the appliance must also conform with
the requirements of the distributors and com­ply with current Regulations and laws in force.

The safety relief valve and the condensate
drain must be connected to a suitable drain, or
discharge in a safe manner.

INSTALLATION

The electrical wiring must conform with current
Regulations, in particular:

---

the boiler
rect bonding clamp.

---

a fused spur isolation switch, with a gap of
at least3 mm between the contacts mustbe
installed near to the boiler. Refer to section

6.9 in this chapter for the electrical connec­tions.

In no circumstances will the manufacturer
be held responsible if the warnings and in­structions contained in this manual have
not been complied with.

must

be earthed using the cor-

6.2 Precautions for installation

For the installation proceed as follows:

---

The boiler must be fixed to a strong wall.

---

The dimensions for the exhaust fume duct de­tailed in section6.7 and the correctprocedures
for installing the duct, depicted in the instruc­tion leaflet included with the flue kit, must be
complied with during installation.

---

To allow maintenance procedures it is necess­ary to leave the minimum gaps indicated in
Fig. 6.1.

200

25 50

200

Fig. 6.1 (all dimensions in mm)

---

When installing the boiler in a cupboard, cover
or alcove allow at least50mm permanent clear­ance from the front face of the boiler. Also en­sure sufficient clearance to allow free access
for servicing and the lowering of the front con­trol panel.

---

If the boiler is installed outside, cover the ap­pliance to protect it against the elements and
add some special anti--- freeze (neutralised) to
the c.h. system.

---

Before installing the boiler on an existing c.h.
system, flush it out thoroughly before fitting the
boiler, so as to remove muddy deposits.

---

It is advisable to equip the system with a sedi­ment filter, oruse a water--- treatment product in
the circulating water.
The latter option in particular, not only cleans
out the system, but also has an anti---corrosive
effect by promoting formation of a protective
skin on metal surfaces and neutralising gases
present in the water.
We recommend the use of a suitable universal
inhibitory to protect the c.h. system from cor­rosion.

6.3 Installing the bracket

Precautions

Before mounting the bracket, check that the di­mensions for fitting the exhaust fume duct are
complied with (refer to the leaflet included with the
flue kit, packed separately).

24

Installation

Utilise the paper template supplied with the boiler
to determine the fixing position for the bracket and
boiler. Securely mount the bracket to the wall
using appropriate fixings suitable for the type of
wall construction and capable of supporting the
total (wet) load. Refer to the weight given in the
technical data tables specific for each model.

6.4 Overall dimensions

200

65645265
200

B

ø100

31

16

C.h.

return

Condensate drain

A

A, B and C

190

Boiler front

350

connection

area

C

ø80 ø80

803

245

196

50

35

700

60 60

C.h.
flow

47

115 142

Electric

connection

area

100

D.h.w.

outlet

*

400

Gas

73

257

Cold

water

inlet

**

A --- air intake/flue outlet pipe (co---axial)
B --- flue outlet pipe ø 80 mm (twin kit)
C --- air intake pipe ø 80 mm (twin kit)
* not present on c.h. only boilers

Fig. 6.2 (all dimensions in mm)

6.5 Joints

Functions Pipe sizes (o.d)

Gas, c.h. return, c.h. flow ø 22

D.c.w. inlet * ø 15

D.h.w. outlet * ø 15

Pressure relief valve ø 15

Condensate drain ø 25 (plastic)

* not present on c.h. only boilers

Tab. 6.1 (sizes in mm o.d.)

6.6 Mounting the boiler

1 Take the protective caps off the boiler pipe-

work.

2 Thoroughly clean the connections.

3 Mount the boiler on its bracket.

4 Fix the c.h. valves A and gas cock B (¾”) to the

boiler using the ¾” gaskets (Fig. 6.3)

5 Fix the ø 22 mmpipes C (c.h. circuit) to the c.h.

valves A and the ø 22 mm pipe D (gas) to the
cock B using the ¾” gaskets.

6 Repeat the above procedure for the d.c.w. inlet

utilising the ½” cold water inlet valve E, the ø 15
mm copper tail F with its connection nut and
two ½” gaskets.

7 Fix the ø 15 mm copper tail G with the ½” con-

nection nut and a ½” gasket.

C

D

G

F

C

A

B

E

A

Fig. 6.3

INSTALLATION

25

Installation

8 Connect the pipe H (Fig. 6.4) from the pres-

sure relief valve to the safety discharge pipe­work.

9 Fit the condensate drain 11 (Fig. 6.4) in the air

brake connected to the drainage pipework.
See also section 5.7 in this manual.

INSTALLATION

11H

Fig. 6.4

6.7 Fitting the flue system

Refer to the assembly instructions contained with­in the chosen flue kit packaging for the correct as­sembly and installation.

In general, it has to be taken in consideration that
the horizontal sections of the flue pipe must have
an horizontal sloping not less than 1.5 deg. (25
mm per metre) towards the boiler.

In the standard horizontal flue kit (Fig. 6.5A) the
flue pipe is angled within the air duct therefore the
air duct must be horizontally installed.

If one or more extensions have to be used they
must be adequately supported so that there is no
sag in the flue pipe and a minimum fall of 1,5 deg.
(25 mm per metre) over the whole length towards
the boiler is ensured.

6.8 Choice of flue

The following flue kits are available for connecting
to the boiler:

Standard horizontal flue kit (Fig. 6.5A)

Co--- axial 60/100mm --- nominal length 1m

This kitis normally supplied with the boiler and can
be fitted to allow discharge to the rear or either
side of the boiler via the flanged boiler adapter
elbow. Minimum length required is 0.3 m. Maxi­mum equivalent length of 2,7 metres can be
achieved utilisingextensions. This flue system can
only be used to discharge horizontally, it is not de­signed to enable termination in the vertical plane.

Vertical kit with 90° elbow (Fig. 6.5B)

Co--- axial 60/100 mm

Supplied with a straight flanged adapter a co --­axial elbow and a co---axial pipe with terminal, this
kit allows for a vertical rise of 0,5 m from the boiler.
In all circumstances the flue terminal must dis­charge horizontally and the equivalent flue length
must not exceed 2,7 metres.

Elbows 45° & 90° (Fig. 6.5C)

Co--- axial 60/100mm.

Elbow kits enable the standard flue kits to be offset
to overcome obstructions or ensure the correct
clearances for the flue terminal. Each elbow used
in addition to the standard flanged elbow reduces
the overall acceptable length of the flue system as
follows:

45° reduce length by 0.5 m.
90° reduce length by 1 m.

B

ø 60/100

Min = 0,3 m

Max = 2,7 m

A

ø 60/100

90° =--- 1m

45° =--- 0,5m

C

Fig. 6.5

Twin pipe kits ø 80 mm (Fig. 6.6)

Various twin (split) pipes kits and optional acces­sories (elbows) are available to assist in the ter­mination of the flue where the boiler is installed in
a location remote to an outside wall.

These kits allow for separation of the air supply
pipe from the pipe that discharges the exhaust

26

Installation

gasses. Consequently it is possible to extend the
flue system to a greater distance than that pro­vided by the standard horizontal co--- axial flue.

If either an additional 45° or 90° accessory elbow
is used then the maximum permissible length of
either pipe must be reduced by 0.90 m or 1,65 m
respectively.

90° =--- 1,65 m

45° =--- 0,90 m

Fig. 6.6

Two restrictors with different size are supplied
with the twin pipe kit and have to be installed
between the boiler and the air intake adapter
(Fig. 6.7).

Air intake adapter

This kit allows vertical termination of the flue pipe
through the roof. The kit is 1.2 m in length. Exten­sion pieces (Co--- axial) are also available which al­lows the flue system to be extended to a total
overall maximum permissible length.
Optional 45° and 90° elbows can be used to offset
the flue route.

Each additional elbow reduces the overall accept­able length of the flue system as follows:

45° reduce length by 0.5 m.
90° reduce length by 1 m.

90° =--- 1m

INSTALLATION

max = 8.5 m

45° =--- 0,5m

Fig. 6.8

Restrictor

Gasket

Fig. 6.7

For the correct use of the restrictors

pipes

refer to Tab. 6.2.

Equivalent length

with twin

Restrictor

(air duct + flue duct)

Between 1 and 15 m ø 50 mm

More than 15 m up to 30 m ø 55 mm

6.9 Electrical connections

Connection to the electricity supply

1 Remove the front panel of the case (see the

section 9.2 in this manual).

2 Remove the screws I and J (Fig. 6.9).

3 Loosen the screws K.

Tab. 6.2

Vertical--- roof kit (Fig. 6.8)

27

Installation

I

J

K

J

INSTALLATION

Fig. 6.9

4 Remove the side panels or move the lower part

of the side panels as indicated in Fig. 6.10 and
pull the control panel.
When completely pulled out, the panel can ro­tate 45° downwards to facilitate the operations
on the internal parts.

L

Fig. 6.11

For the electrical connection to the boiler use elec­tricwires which conform to the current regulations,
with flexible cord, each core having a cross sec­tion area

6 Connect the electrical supply flexible cord

coming from the fused spur isolation switch to
the power supply terminal block of the boiler
(Fig. 6.12) keeping the same connections for
the live (brown wire) and the neutral (blue
wire). External 3 A fuse or fused plug with same
current rating is recommended.

Do not connect live wires to terminals to
which the room thermostat must be con­nected.

Connect the earth wire (yellow/green).

7

not less than 0,75 mm

2

.

Fig. 6.10

5 Loosen the screws L and remove the service

panel (Fig. 6.11).

Connection of a room thermostat

The room thermostat must be connected to the
terminal block situated next to the control panel.

When connecting any type of external control,
the link M in Fig. 6.12 must be removed.

28

Installation

L N

Power supply
terminal block

12

External controls
terminal block

M

To fused spur
isolation switch

3

Fig. 6.12

8 Connect the room thermostat between ter-

minals 1 and 3 as shown in Fig. 6.13.

Do not connect live wires to terminals to
which the room thermostat must be con­nected.

Room thermostat

Power supply
terminal block

L N

T

To the external
control device

To the fused spur
isolation switch

Fig. 6.14

6.10 External frost protection

10 Connect the frost thermostat between ter-

minals 1 and 2 as shown in Fig. 6.15.

Do not connect live wires to terminals to
which the room thermostat must be con­nected.

Frost thermostat

Room thermostat

INSTALLATION

External controls
terminal block

3

12

Fig. 6.13

9 Route the electrical supply flexible cord and

the external control flexible cord as illustrated
in Fig. 6.14.
Lock the flexible cords in place with the flexible
cord clamps

L N

T

3

Fig. 6.15

T

Power supply
terminal block

12

External controls
terminal block

6.11 Connecting a M96.28SR/...

system boiler to a cylinder

Two schematic wiring diagrams are given in this
section showing two possible ways to connect an
external programmer to a mid --- position diverter
valve to provide independent timed and thermo­static control of heating and hot water.

In both diagrams the earth wires are not shown for
clarity. Earth wiring

must

be fitted as necessary.

29

Installation

L

N

MAINS
230V a.c.
Switched 3 Amp fused,
spur

Valve colour key
BR --- Brown

BL --- Blue
GR --- Grey

INSTALLATION

OR --- Orange

Fig. 6.16 --- relay controlled boiler

Programmer

Room thermostat

Cylinder
thermostat

BL

GRBROR

Mid--- position
diverter valve

Relay

Remove room
thermostat link

L N

Power supply
terminal block

321

M96.28SR/...

External control

terminal block

L

N

MAINS
230V a.c.
Switched 3 Amp fused,
spur

Valve colour key
BR --- Brown

BL --- Blue
GR --- Grey
OR --- Orange

Programmer

Fig. 6.17 --- directly controlled boiler

Room thermostat

Cylinder
thermostat

BL

GRBROR

Mid--- position
diverter valve

L N

Power supply
terminal block

Do not

remove room
thermostat link

321

M96.28SR/...

External control

terminal block

30

7 COMMISSIONING

Ensure that the Benchmark Log Book is satis­factorily commpleted during the commssion­ing process. The Log Book is locatedat the end
of this manual. This manual should be handed
to the User following completion of the installa­tion and commissioning process. Failure to
comply with these requirments may invalidate
the manufacturers guarantee.

7.1 Electrical installation

Preliminary electrical system checks to ensure
electrical safety shall be carried out by a compet­ent person. i.e. polarity, earth continuity, resis­tance to earth and short circuit.

If a fault has occurred on the appliance the fault find­ing procedure should be followed as specified in the
service manual.

7.2 Gas supply installation

1 Inspect the entire installation including the gas

meter, test for soundness and purge, all as de­scribed in BS 6891;

2 Open the gas cock 14 (Fig. 7.1) on the

appliance and check the gas connector on the
appliance for leaks.

14 13

Fig. 7.1

Open position

7.3 Filling the d.h.w. system

1 Close all hot water draw--- off taps.

2 Open the cold water inlet valve 13 (Fig. 7.1).

3 Slowly open each draw --- off tap and close it

only when clear water, free of bubbles, flows
out.

7.4 Initial filling of the system

1 Open the c.h. flow and return valves.

2 Remove the front panel of the case (see the

section 9.2 in this manual.

3 Unscrew the cap on the automatic air purger-

valve 19 (Fig. 7.2) one full turn and leave open
permanently.

4 Gradually open stopcock at the filling point

connection to the c.h. system until water is
heard to flow; do not open fully.

19
21

Fig. 7.2

5 Open each radiator air vent starting at the

lowest point of the system and close it only
when clear water, free of bubbles, flows out.

6 Purge the air from the pump by unscrewing the

pump plug 21 (Fig. 7.2); release the pump
shaft by turning in the direction indicated by
the arrow on the information plate.

7 Replace the pump plug.

8 Continue filling the system. The actual reading

should ideally be 1,3 bar and not less than 0,3
bar.

9 Close all air release valves on the c.h. system.

10 Inspect the boiler and the system for water

soundness and remedy any leaks discovered.

11 Cold flush the system to remove any loose par-

ticlesand any system debris before starting the
boiler for the first time

The flushing procedure must be in line with
BS7593

tems.

Treatment of Water in d.h.w. c.h. Sys-

INSTALLATION

31

Commissioning

When the installation and second filling are
completed turn on the c.h. system and run it
until the temperature has reached the boiler
operating temperature. The system must then
be immediately flushed through.

This procedure must be repeated twice more.

During this operation we highly recommend
the use of a c.h. flushing detergent in the quan­tities as specified by the appropriate manufac­turer, whose function it is to dissolve any
foreign matter which may be in the system.

The above operation could save the invalida­tion of your boilers guarantee and will also pre­vent problems which you may experience in
the future if an inhibitory is not used.

INSTALLATION

7.5 Condensate pipe and traps

The full length of the condensate pipe should be
check for leaks.

The boiler has a built--- in condensate trap pro­vided with a ball valve that prevents the escape of
combustion products when the trap is empty.

It is however recommended that any other trap
in the drain system is correctly filled with water
before to run the boiler.

810 7 6

Fig. 7.3

810 7 6

Fig. 7.4

The boiler will now go through an ignition se­quence and the burner will light.

If during the ignition attempt period the boiler fails
to light, the full sequence control p.c.b. will go to
lockout and the lock--- out signal lamp 6 will ap­pear.

To reset the boiler press and release the boiler re­set button 7 (Fig. 7.3).

7.6 Lighting the boiler

Some products incorporate an anti cycling time
delay. It isnormal when first switching the boiler on
for the boiler to operate on heating for a few sec­onds then switch off. After 3 --- 4 minutes has
elapsed the boiler will then re ignite and operate
perfectly normally. The ignition delay cycle does
not prevent normal operation of the boiler to pro­vide d.h.w..

If external controls are fitted (e. g. Timeclock, room
thermostat) ensure they ”call for heat”.

1 Turn on the electricity supply to the boiler,

switching on the fused spur isolation switch.
The appliance operation light 10 will flash
every 4 seconds.

2 Turn the function selector 8 as in Fig. 7.3

(combi) or Fig. 7.4 (c.h. only). The appliance
operation light 10 will flash every 2 seconds.

7.7 Checking the gas pressure at

the burner

This boiler has been tested to the highest qual­ity control standards.

The maximum and minimum gas pressures are
already set during this quality control process
however the checking procedure must be fol­lowed to ensure maximum operating efficiency
from the boiler.

1 Remove the front panel of the case (see sec-

tion 9.2 in this manual).

2 Loosen the internal screw 41 (Fig. 7.5) on the

Outlet Pressure Test Point of the Gas Valve and
connect a pressure gauge using a suitable
hose.

32

Commissioning

3 Set the d.h.w. and c.h. temperature control

knobs to their maximum position.

4 Switch on the boiler and open at least one hot

water tap fully.

5 Check the maximum gas pressure and com-

pare the value on the gauge with the value indi­cated in the sections 4.6 or 4.7 (gas pressures
at the burner), accordingly with the model of
boiler installed.

6 Check the maximum gas flow at the gas meter

and compare the value indicated in the sec­tions 4.6 or 4.7 (gas rate), accordingly with the
model of boiler installed.

7 Switch off the boiler.

8 Disconnect the gas modulator coil by remov-

ing the electrical connector A (Fig. 7.5).

41

A

indicated in the sections 4.6 or 4.7 (gas pres­sures at the burner), accordingly with the
model of boiler installed.
If the ignition gas pressure is not set correctly
see section 7.8 in this manual for the adjust­ment procedure. If ignition gas pressure is cor­rect switch dip--- switch ”3” to the ON position.

15 Switch off the boiler, turn off the hot water tap(s)

and disconnect the pressure gauge.

If the maximum and minimum gas pressures
measured above are not in accordance with the
technical data (sections 4.6 or 4.7) then adjust­ment willbe necessary. A full explanation of the
gas pressure adjustment procedure is given in
the Gas Valve section of the service manual. If
maximum and/or minimum gas pressures are
adjusted then the ignition gas pressure must
be checked and adjusted if necessary.

Important: after the gas pressure checks and
any adjustment operations, all of the testpoints
and adjustment devices must be sealed.

INSTALLATION

Fig. 7.5

9 Switch on the boiler.

10 Check the minimum gas pressure and com-

pare the value on the gauge with the value indi­cated in the sections 4.6 or 4.7 (gas pressures
at the burner), accordingly with the model of
boiler installed.

11 Switch off the boiler and re---connect the elec-

trical connector A to the modulator coil.

12 Access the main control panel (see section 6.9,

follow steps 2 --- 5)

13 Switch on the boiler.

14 Check the ignition gas pressure by setting

dip--- switch ”3” (Fig. 7.8) to the OFF position.
Compare the value on the gauge with the value

7.8 Adjusting the burner ignition

1 Turn off the boiler by means of the fused spur

isolation switch provided adjacent to the ap­pliance.

2 Make sure that the function selector 8 is set to

the position in Fig. 7.6 and that the timer selec­tor switch and room thermostat, if fitted, is set
to “demand heat”.

Fig. 7.6

3 Unscrew the gas valve’s outlet pressure test

point 41 (Fig. 7.5) and connect a pressure
gauge.

33

Commissioning

4 Loosen the screws B and remove the service

panel (Fig. 7.7).

B

Fig. 7.7

5 Turn on the boiler.

INSTALLATION

6 Check that the boiler lights up uniformly and

adjust the ignition gas pressure, if necessary.

To adjust the ignition gas pressure, set dip--- switch
”3” (Fig. 7.8) to the OFF positionand adjust poten­tiometer marked “ACC” with a screwdriver until
correct ignition gas pressure is obtained.

+

RISC

+

ACC

ON

2 3

1

4

is set to the ’OFF’ position there will be approxi­mately 30 seconds re--- ignition delay period.

Whilst checking or adjusting the c.h. output, and
fault finding on the boiler it may be necessary to
switch the re--- ignition delay mechanism (dips­witch 4) to the ’OFF’ position.

Refer to the diagrams shown in Fig. 7.9, Fig. 7.10
or Fig. 7.11 and select the correct central heating
output gas pressure to meet with the central heat­ing system requirements.

With the boiler operating in c.h. mode, use a suit­able screwdriver to turn the adjustment potentio­meter marked “RISC” (Fig. 7.8).
Rotating the potentiometer anti --- clockwise re­duces the maximum supply current to the gas
modulator device, and thus reduces the gas pres­sure to the burner.

kW

Natural (G20)
29
27
25
23
21
19
17
15
13
11

9

1 2 3 4 5 6 7 8 9 10 11

M96.24SM/...
M96.28SM/... M96.28SR/...

mbar

Fig. 7.9

OFF

Fig. 7.8

Refer to the table gas pressures at the burner in the
sections 4.6 or 4.7 for appropriate value.

7 Having finished this procedure, reset dip---

switch ”3” to the ON position.

7.9 Adjustment of useful c.h.

output

If the burner function selector (dipswitch number
4 on the main P.C.B.) is set to the ’ON’ position it
will activate the re --- ignition delay period of ap­proximately 4 minutes. When dipswitch number 4

34

Commissioning

kW

28
26
24
22
20
18
16
14
12
10

5 7 9 11 13 15 17 19 21 23 25 27 29

M96.24SM/...
M96.28SM/... M96.28SR/...

Fig. 7.10

kW

29
27
25
23
21
19
17
15
13
11

9

7 10 13 16 19 22 25 28 31 34 37

M96.24SM/...
M96.28SM/... M96.28SR/...

Fig. 7.11

Butane (G30)

mbar

Propane (G31)

mbar

7.10 Checking the ignition device

With the burner on high flame close the gas cock.
About 10 seconds after, the lock--- out signal lamp

6 (Fig. 1.3 on page 2) must appear.
To reset the boiler press and release the boiler

reset button 7 (Fig. 1.3 on page 2).

7.11 Checking the flue system

The flue system should be visually checked for
soundness. Check all clamps, gaskets and fixings
are secure and tight.

Ensure that the flue terminal is sitedcorrectly in ac­cordance with the flue fitting instructions and
Fig. 5.1 on page 20 of this manual.

To carry out a combustion check refer to the in­structions given in the section 9.5 of this manual.

Reference figures are given in the sections 4.6 or

4.7 of this manual (Flue gas figures).

7.12 Checking the condensate

drain pipe

Check the soundness and integrity of the conden­sate drain pipe.

Verify the cleaness and correct filling of the con­densate traps.

7.13 Instructing the user

Hand over this combined User & Installation man­ual and the Service manual to the end user and ex­plain how to use the unit in both c.h. and d.h.w.
modes.

Take the User step by step through the lighting in­structions.

Show the User how to switch off the appliance
quickly and indicate the position of the electric
supply isolator.

Explain the proper use and adjustment of all sys­tem controls; this will ensure the greatest possible
fuel economy.

Explain the function and use of the function selec­tor.

Explain and demonstrate the function of time and
temperature controls (if fitted).

Explain how to turn off the appliance for both short
and long periods and advise on the precautions
necessary to prevent damage should the
appliance be inoperative when freezing condi­tions may occur.

Fill in the details required on the Boiler Guarantee
Certificate and hand to the User advising them to
return the correct section for boiler Guarantee reg­istration.

Finally, advise the User that, for continued safe
and efficient operation, the appliance must be ser­viced by a competent person at least once a year.

INSTALLATION

35

8 GAS CONVERSION

NaturalgasL.P.G

.

8.1 Warnings

Procedures to adapt the boiler to the type of
gas available

must be carried out

by a com-

petent and responsible person.

Components used to adapt it to the type of gas
available must be genuine parts only.

8.2 Procedures

1 Check that the gas cock (14 in Fig. 9.3) fitted

under the boiler is turned off and the appliance
is is switched off at the mains isolating spur.

2 Remove the front and side panels of the case

(see the section General access and emptying
hydraulic circuits in the service manual).

3 Take off the lid of the sealed chamber.

4 Take the front panel of the combustion

chamber off and remove the burner (29 on
page 12). See section Ignition and detection
electrodesin theservice manual for detailed in­structions.

5 Carry out the conversion for the type of gas, re-

placing the burner injectors correctly.

6 Re--- assemble the burner, the front panel of the

combustion chamber and the lid of the sealed
chamber.

7 Extract the control panel as explained in the

section 6.9 of this manual.

MAINTENANCE

8 Loosen the screws C and remove the service

panel (Fig. 8.1).

C

9 set correctly the dip--- switch ”2” to the correct

position (Fig. 8.2) in accordance with the follo­wing table.

Gas supply Position of dip---switch 2

Natural gas On

L.P.G. Off

ON

1 2 3

OFF

4

ON

2

OFF

4

3

1

Fig. 8.2

10 Calibrate the gas valve according to the in-

structions given in the service manual, section
Modulating gas valve --- Adjustment.

11 Set the correct gas pressure for central heating

output required, see section 7.9 in this manual.

12 Stick on the inside of the left hand side panel

adjacent to the data badge the self--- adhesive
label (included with the conversion kit) indicat­ing the type of gas, and the gas pressures to
which the appliance has been set.

13 Replace the service panel, the front and side

panels of the case.

Fig. 8.1

36

9 MAINTENANCE

9.1 Warnings

The procedures detailed in this chapter

be carried out only by a professionally
qualified person.

contact an Authorised Service Agent.

For efficient and continuous operation of the
boiler you are advised to have, at least once a
year, maintenance and cleaning done by an
Approved Service engineer.

Isolate the appliance from the electricity
supply

switch adjacent to the appliance and

the gas

cedures, whatsoever, for cleaning, mainten­ance, opening or dismantling boiler panels.

by turning off the fused spur isolation

cock, before carrying out any pro-

Thus you are advised to

must

turn off

9.2 Dismantling the external

panels

Front panel

1 Loosen the three screws A (Fig. 9.1).

2 Lift and remove the panel.

Side panels

3 Loosen the screws B. Bring the bottom of the

panels away from the boiler and lift them, free­ing them from the top hooks (Fig. 9.2).

B

Fig. 9.2

Air--- Flue exhaust
Sampling points

9.3 Emptying the d.h.w. system

(combi)

1 Turn off the d.c.w. inlet isolating valve (13 in

Fig. 9.3) and turn on the hot water taps and any
drain cocks.

Closed position

A

12

141316

Fig. 9.3

MAINTENANCE

9.4 Emptying the c.h. system

Fig. 9.1

1 Close the c.h. isolating valves (12 and 16 in

Fig. 9.3).

2 Open the central heating drain cock (18 in

Fig. 9.4).

37

Maintenance

3 A small quantity of water will remain in the

d.h.w. heat exchanger after draining. If the
boiler is being drained to prevent freezing, the
d.h.w. heat exchanger must be removed and
inverted to drain fully or an antifreeze solution
added.

18

Fig. 9.4

9.5 Combustion analysis check

If it is necessary to carry out a combustionanalysis
remove the plugs indicated in Fig. 9.1.

Reference figures are given in the sections 4.6 or

4.7 of this manual (Flue gas figures).

9.6 Cleaning the primary heat

MAINTENANCE

1 Take off the front of the case.

2 Take off the removable front of the air--- tight

If you notice dirt on the fins of the primary heat ex­changer (31 on page 12):

3 cover the sloping surfaces of the burner (29 on

4 Brush out the primary heat exchanger (31 on

NOTE --- When removing the airtight chamber
cover it is not necessary to remove the screws lo­cated at the top edge on either side.

exchanger

chamber and the front panel of the combustion
chamber.

page 12) entirely in a protective layer (sheetsof
newspaper or similar).

page 12) with a bristle paintbrush.

sure in the expansion vessel is not less than 1 bar.
See also section 4.5 page 15 of this manual.

If the pressure is lower, take steps to correct the
pressure level.

9.8 Cleaning the burner

The sloping and multi---gas type burner (29 on
page 12) does not need special maintenance, but
it is sufficient to dust it with a bristle paintbrush.

To reach the burner:

1 Take off the front of the case.

2 Take off the removable front of the air--- tight

chamber and the front panel of the combustion
chamber.

3 Brush out the burner with a bristle paintbrush.

NOTE --- When removing the airtight chamber
cover it is not necessary to remove the screws lo­cated at the top edge on either side.

9.9 Checking the flue

Have the integrity of the flue outlet pipe (49 on
page 13) air intake pipe (50 on page 13), checked
periodically, the venturi device* (46 on page 13)
cleaned and the efficiency of the flue safety circuit
checked at least once a year.

* For details see the section Fan, venturi device
and air pressure switch in the service manual.

For all the above maintenance operations it is ad­visable to call an approved Service Engineer.

9.10 Drain pipe inspection

Check the soundness and integrity of the conden­sate drain pipe.

Verify the cleaness and correct filling of the con­densate traps.

9.11 Visual inspection of

appliance

Visually inspect all water joints, seals and connec­tions for any evidence of leakage and retighten,
grease or replace them as necessary.

9.7 Checking the pressurisation

in the expansion vessel

Empty the central heating system as described in
section 9.4 of this chapter and checkthat thepres-

38

9.12 Gas pressures and soundness

Check appliance for gas soundness. Recheck op­erational pressures and adjust as necessary as
described in section 7.7 page 32 of this manual.

Maintenance

MAINTENANCE

39

*1796211132*

17962.1113.2 0605 48A5 UK

Biasi U.K. Ltd
Unit 31/33, Planetary Road
Industrial Estate, Neachells Lane
Willenhall, Wolverhampton WV 13 3XB
Technical helpline: 01902 304 400
Web site: www.biasi.co.uk