Ariston INTESA TP23 User manual

Country of destination: GB - IE
Users Guide
Installation and Servicing Instructions
TP 23 - G.C. Number 47-116-32
TP 30 - G.C. Number 47-116-33
Manufacturered by Merloni TermoSanitari spa - Italy

TABLE OF CONTENTS
2
USERS GUIDE
1. GENERAL INFORMATION
2. OPERATING INSTRUCTIONS
3. BOILER SHUTDOWN SITUATIONS
4. TIME CLOCK
INSTALLATION AND SERVICING
INSTRUCTIONS
5. GENERAL INFORMATION
5.1 General Instructions
5.2 Overall View
6. INSTALLATION
6.1 Reference Standards
6.2 Siting the Appliance
6.3 Overall Dimensions
6.4 Clearances
6.5 Mounting the Appliance
6.6 Electrical Connection
6.7 Gas Connection
6.8 Water Connections
6.9 Flue Connection
6.10 Control Panel
6.11 Removing the front panel
6.12 Fitting the Time Clock
6.13 Room Thermostat Connection
6.14 Electrical/System Diagrams
6.15 Water Circuit Diagram
7. COMMISSIONING
7.1 Initial Preparation
7.2 Initial Start up
7.3 Operational Adjustments
7.4 Combustion Analysis
7.5 Product of Combustion Discharge Monitoring
7.6 Boiler Safety Systems
7.7 Draining the System
7.8 Completion
7.9 Operational checks
7.10 Instructing the End User
8. GAS ADJUSTMENTS
8.1 Changing the Type of Gas
8.2 Adjusting the gas pressure
9. MAINTENANCE
10. SERVICING INSTRUCTIONS
10.1 Replacement of Parts
10.2 T
o Gain General Access
10.2.1 Removing the Front Panel
10.2.2 Removing the Sealed Chamber Front Panel
10.2.3 Removing the Side Panels
10.3 Access to the Combustion Chamber
10.3.1 Removing the Combustion Cover
10.3.2 Removing the Burner and Jets
10.3.3 Removing the Electrodes
10.3.4 Removing the Main Heat Exchanger
10.3.5 Removing the Air Pressure Switch
10.3.6 Removing the Fan
10.4 Access to the Gas Valve
10.4.1 Removing the Spark Generator
10.4.2 Removing the Gas Valve
10.5 Access to the Water Circuit
10.5.1 Removing the D.H.W.(secondary) exchanger
10.5.2 Removing the Pump Pressure Switch
10.5.3 Removing the Safety Valve
10.5.4 Removing the Automatic Air Vent
10.5.5 Removing the Pump
10.5.6 Removing the Pressure Gauge
10.5.7 Removing the Expansion Vessel
10.5.8 Removing the Overheat Thermostat
10.5.9 Removing the Central Heating Temperature
Sensor (N.T.C.)
10.5.10Removing the D.H.W.Temperature Sensor (N.T.C.)
10.5.11Removing the D.H.W. Flow Switch
10.5.12Removing the Divertor Valve Actuator
10.6 Access to the Control System
10.6.1 Checking the Fuses
10.6.2 Removing the Time Clock
10.6.3 Removing the P.C.B.
11. FAULT FINDING
11.1 Fault Finding Guide (Flow-chart)
12. SHORT SPARE PARTS LIST
13. TECHNICAL INFORMATION

3
1. General Information
This is a combined appliance f or the production of centr al heat-
ing (C.H.) and domestic hot water (D.H.W.). This appliance must
be used only for the purpose for which it is designed. The man-
ufacturer declines all liability f or damage caused b y improper or
negligent use.
Do not allow children or inexperienced persons to use the appli-
ance without supervision.
If you smell gas in the room, do not turn on light switches, use
the telephone or any other object which might cause spar ks.
Open doors and windows immediately to ventilate the room.
Shut the gas mains tap (on the gas meter) or the valve of the gas
cylinder and call your Gas Supplier immediately.
If you are going away for a long period of time, remember to shut
the mains gas tap or the gas cylinder v alve.
Before any intervention within the boiler it is first necessary
to cut off the electrical power supply by turning the external
switch to “OFF”.
Control Panel
ABC
DEFI HGK J
LEGEND:
A- On/Off button
B- Central heating temperature adjustment
C-Domestic hot water temperature adjustment
D- Heating system pressure gauge
E- Time clock
F- Central heating selector
G- Central heating L.E.D. (green)
H- Flue sensor L.E.D.(yellow)
I- Ignition failure (lockout) and/or overheat reset button
J- Overheat and/or ignition failure (lockout) L.E.D. (red)
K- ON/OFF L.E.D. (green)
To get the most out of y our boiler, we have provided you with
some useful advice on proper use and maintenance:
- Periodically check the system pressure
using the pressure gauge “D”, make sure
that the pressure is at 1.5 bar when the sys-
tem is off and cool. If the pressure is belo w
the minimum recommended value.
Consult your installer for checking and refill-
ing the system.
- The outer panels of the units case must only be cleaned with a
damp cloth. Do not use abr asive cleaners. The control panel
can be wiped with either a damp or dr y cloth. Spray polishes
must not be used on the control panel surf ace or knobs.Care
must be taken in preventing any liquid entering the appliance.
- If the water is very hard, it is recommended that a water soften-
er be added to the system so as to reduce the f ormation of
limescale in the heat e xchanger.This will ensure that the effi -
ciency of the unit remains the same o ver time, reducing gas
consumption and maintenance costs.
-If the boiler should be out of use f or a prolonged per iod, it is
recommended that the electr ical power supply be disconnect -
ed and that the e xternal gas coc k be closed. If low tempera-
tures are expected, the boiler and system pipe work should be
drained in order to prevent frost damage.
- To improve comfort and tak e full adv antage of the heat pro-
duced by the boiler, it is recommended that an external (room)
thermostat be installed.
- It is good practice to clean and service the appliance and cen-
tral heating system every year.
Call an Authorised Service Centre.
2. Operating Instructions
Installation, start-up, adjustments and maintenance must be
performed by a competent per son only, in accordance with
the current Gas Safety (Installation & Use) Regulations and
the instructions pr ovided. Improper installation may cause
damage or injury to individuals, animals and personal prop-
erty, for which the manufacturer will not be held liable.
To ensure efficient and saf e operation it is recommended
that the boiler is serviced annually by a competent person.
If it is kno wn or suspected that a fault e xists on the appli-
ance, it must not be used until the fault has been corrected
by a competent person.
D
Ignition Procedure
Press button “A”. The green L.E.D. “K” will
illuminate indicating that the boiler is ready to
operate. The centralised electronic control unit
will ignite the b urner, upon demand f or either
C.H. or D.H.W. If, after approximately 10 sec-
onds, the b urner has not ignited, the boiler
safety devices will shut off the gas and the red
L.E.D. “I” illuminates. To reset the ignition sys-
tem, the reset “J” must be pressed and
released. Should the boiler f ail to ignite a sec-
ond time, check that the e xternal gas coc k is
open (see diagrams on the left). If the problem
persists, contact a local Service Agent.
IMPORTANT!! Always wait 2 min utes before
resetting each time.
K
A
I
J
USERS GUIDE

In the event that the safety limit is exceeded for
the temperature of the w ater in the boilers
exchanger, the ther mostat shuts off the boiler
and the red LED “I” illuminates.
To remedy this situation, w ait a few minutes to
allow the exchanger to cool do wn, then press
and release the reset button “J”.
If this situation occurs frequently , contact a
local Service Agent.
4
In the ‘winter operating mode’, the boiler will
produce both Centr al Heating and Domestic
Hot Water. In the ‘summer operating mode’, the
boiler will produce only domestic hot water.
Press button “F” to select winter mode . The
green LED “G” will illuminate.
Winter and Summer Operating Modes
Adjusting the Heating
It is possib le to set the temper ature of the
heating system by adjusting the knob “B”.
By positioning the indicator some where
between MIN and MAX, a temper ature may
be obtained which v aries from approximately
42°C to about 82°C. B
External (Room) Thermostat Control
If an external (room) ther mostat is installed, it is recommended
that the temperature of the heating system be set b y means of
the knob “B”, leaving it at MAX position in order to obtain the
best performance from the boiler and to allo w the regulation of
the external temperature to function efficiently.
Setting the Hot Water for Domestic Use
Both in the winter and summer mode , the temper ature of the
domestic hot water may be adjusted by rotating the knob “C”.A
delivery temperature for the w ater may be
selected between approx. 36°C to 54°C ,
depending on the flow rate of the water and
the position of the knob betw een MIN and
MAX settings.NOTE:Should the Domestic
Hot Water not be hot enough, it may be
necessary to slow the flow rate from the
hot water outlet being used.
C
Turning Off the Central Heating
To turn off the Centr al Heating, press the Centr al
Heating button “F”;the respective green LED “G”
will go off .The boiler will sta y in summer mode ,
only providing Domestic Hot Water
Turning Off the Boiler
To turn the boiler off , press the b utton “A”;the
respective green LED “K” will go off.
The boiler is equipped with saf ety devices that intervene in cer-
tain situations and shut it off. Most of these situations are commu-
nicated by means of the LED’s and at times the user may be able
to remedy them.
Shutdown Due To Ignition Failure
In the event that the automatic ignition of the
burner has failed, the red LED . “I” will illumi-
nate. In order to reset the ignition, the b utton
“J” must be pressed and released. Should the
boiler fail to ignite a second time, check that the
external gas cock is open. If the problem per-
sists, contact a local Ser vice Agent.
IMPORTANT!! Always wait 2 min utes before
resetting each time.
Shutdown Due To Overheating
Temporary Shutdown Due To Defective
Discharge of Exhaust Fumes
The boiler is fitted with saf ety devices, which in the e vent of a
defective discharge of exhaust products, automatically interrupts
the gas supply, thereby shutting off the boiler.
The shut-off of the boiler is tempor ary and is indicated b y the illumi-
nation of the yellow L.E.D. “H” for a period of about 15 minutes.
Once this time per iod has passed and the discharge state of
exhaust system has retur ned to normal, the boiler automatically
turns back on.
IMPORTANT!
If this situation occurs frequently, contact a local Service Agent so
that they may check that the e xhaust fumes are being e xpelled
correctly, that the flue is installed correctly and that the area is
ventilated properly.
3. Boiler Shutdown Situations
G
F
G
F
K
A
I
J
I
J

5
Shutdown Due To Insufficient Circulation
If the boiler is off , one possible cause for this state is an insuffi-
cient pressure of water in the system.
Check the system pressure on the pressure
gauge “D” and if it is less than 0.5 bar , re-
pressurise the system as instr ucted by your
installer, should y ou be unsure some basic
instructions are provided hereafter;
Ensure that the filling loop hose is connected to the cold w ater
inlet pipe and to either the Centr al Heating flow or return
Open the handle/s or tap/s to allow water into the Central Heating
system
Once the needle on the pressure gauge reaches 1 Bar, close the
handle/s or tap/s and disconnect the filling loop hose
Should it still be unclear ho w to proceed, please consult y our
installer.
If the boiler does not start up again, contact a local Service Agent.
If there are frequent drops in pressure within the system, ha ve a
plumber check the heating system for possible water leaks.
4. Time clock
Anti-frost Device
The boiler is fitted with a de vice which, in the event that the water
temperature falls below 8
°C the pump activ ates and r uns until a
temperature of 18°C is attained. In the event that the water tem-
perature falls below
3 °C, the diverter valve switches to Domestic
Hot Water and the burner fires and runs on minimum power until
a temperature of 33°C is attained.
This device is only activated when the boiler is operating perfectly and
- the system pressure is sufficient;
- the boiler is powered electrically;
- gas is being distr ibuted.
UT011Ap
Note: the time clock is for central heating control only.
The time clock is provided with 96 switches, called riders, each of
which covers a time interval of 15 minutes (four per hour).
When a rider is switched from the inside (off setting) to the out-
side of the clock border (on setting), the circuit is closed (s witch
on) for a per iod of 15 min utes and then the boiler star ts if the
room thermostat (if installed) or the heating ther mostat require
heat (heating function on).
EXAMPLE
To set the heating of y our home in the time inter val from 7.00
am to 9.30 am and from 7.00 pm to 10.00 pm e very day:
- rotate the outer r ing of the cloc k in a cloc kwise direction until
the correct time of da y (24h) lines up with the arro w on the
clock (at approx. 2 o’clock position);
-under no cir cumstances should the min ute hand be
moved manually;
- make sure all the s witches, i.e. the riders, are placed on the
inside of the clock border;
- pull outward the riders for 7.00 am and 9.30 am, and then all
riders between these two;
- repeat this for 7.00 pm and 10.00 pm.
Other heating intervals may be set in the same w ay.
The timer has approximately 150 hours of batter y back up for
power failure.
The clock is provided with a selector s witch with three positions
(see figure):
1.Position “I” CONSTANT:in this position, the
clock circuit is always closed (switch on), there-
fore the boiler will constantly be on and will only
shut off upon the request of the room ther mo-
stat (if installed) or the heating ther mostat;
2.
Position “O” HEATING OFF: in this position, the
clock circuit is alw ays open (switch off) and the
boiler will therefore never ignite for heating;
3. “Central” Position PROGRAMMING ACTIVE:
in this position, the programming set by the user
is active.
UT014A
UT014A
UT014A
D
3. Boiler Shutdown Situations

6
This manual is an integ ral and essential par t of the product. It
should be kept with the appliance so that it can be consulted b y
the user and our authorised personnel.
Please carefully read the instr uctions and notices about the unit
contained in this man ual, as the y provide important information
regarding the safe installation, use and maintenance of the prod-
uct.
For operating instructions please consult the separ ate Previous
User Guide.
Read the instructions and recommendations in these Installation
Instructions carefully to ensure proper installation, use and main-
tenance of the appliance.
Keep this manual in a safe place.You may need it for your own ref-
erence while our Ser vicing Centre technicians or y our installer
may need to consult it in the future .
This is a combined appliance for the production of central heating
(C.H.) and domestic hot water (D.H.W.).
This appliance must be used only for the purpose for which it is
designed.
The manufacturer declines all liability f or damage caused b y
improper or negligent use.
No asbestos or other hazardous materials have been used in the
fabrication of this product.
Before connecting the appliance, check that the inf ormation
shown on the data plate and the technical data section comply
with the electric, water and gas mains of the property. You will find
the data plate on the reverse of the control panel.
The gas with which this appliance oper ates is also shown on the
label at the bottom of the boiler.
Do not install this appliance in a damp en vironment or close to
equipment which spray water or other liquids.
Do not place objects on the appliance.
Do not allowchildren or inexperienced persons to use the appli-
ance without supervision.
If you smell gas in the room, do not turn on light switches, use
the telephone or any other object which might cause spar ks.
Open doors and windows immediately to ventilate the room.
Shut the gas mains tap (at or adjacent to the gas meter) or the
valve of the gas cylinder and call y our Gas Supplier immediately.
If you are going away for a long period of time, remember to shut
the mains gas tap or the gas cylinder v alve.
Always disconnect the appliance either by unplugging it from the
mains or tur ning off the mains s witch before cleaning the appli-
ance or carrying out maintenance.
In the case of faults or failure, switch off the appliance and turn
off the gas tap.Do not tamper with the appliance.
For repairs, call y our local A uthorised Servicing Centre and
request the use of or iginal spare par ts. For in-guarantee repairs
contact MTS (GB) Limited.
5.1 General Instructions
Check the following at least once a year:
1 - Check the seals f or the w ater connections; replace any
faulty seals.
2 - Check the gas seals; replace any faulty gas seals.
3 - Visual check of the entire unit.
4 - Visual check of the combustion process or analysis of com-
bustion by-products (see section 3.6) and cleaning of the
burner if needed.
5 - If called for by point. 3, dismantling and cleaning of the com-
bustion
chamber.
6 - If called for by point. 4, dismantling and cleaning of the burn-
er jets.
7 - Visual check of the primary heat exchanger:
- check for overheating in the blade assembly;
- clean the exhaust fan if needed.
8 - Adjustment of the flow rate of the gas: flow rate for lighting,
partial load and full load.
9 - Check of the heating safety systems:
- safety device for maximum temperature
(overheat thermostat);
- safety device for maximum pressure (safety valve).
10- Check of the gas safety systems:
- safety device for lack of gas or flame ionisation
(detection electrode);
- safety device for gas cock.
11- Check of the electr ical connection (mak e sure it complies
with the instructions in the manual).
12- Check of domestic hot water production efficiency (flow rate
and temperature)
13- General check of the comb ustion by-products of the dis -
charge/ventilation system.
14- Check of the general performance of the unit.
NOTE:THESE CHECKS ARE NOT EXHAUSTIVE, FURTHER HYDRAULIC,
MECHANICAL, ELECTRICAL AND OPERATIONAL CHECKS MAY BE
REQUIRED AS NECESSARY
.
5. GENERAL INFORMATION
INSTALLATION AND SERVICING INSTRUCTIONS

7
General Information
5.2 Overall View
27
26
25
21
20
24
23
22
9
10
8
13
14
12
15
6
5
4
3
2
128
16 18 1917
11
7
Legend:
1. Flue connector
2. Air intake for twin pipe flue systems
3. Fan
4. Combustion chamber hood
5. Heat exchanger
6. Safety thermostat
7. Combustion chamber
8. Combustion chamber insulation panel
9. Detection electrode
10. Ignition electrodes
11. Pump pressure switch
12. Main circuit temperature probe
13. Safety valve (3 bar)
14. Domestic hot water temperature probe
15. Secondary exchanger
16. Gas valve
17. Spark generator
18. Domestic hot water inlet filter
19. D.H.W. flow switch
20. Drain valve
21. Circulation pump with automatic air release v alve
22. Motorised diverter valve
23. Automatic By-pass
24. Burner
25. Expansion vessel
26. Air pressure switch tube
27. Air pressure switch
28. Combustion analysis points
Fig. 5.0

8
6. INSTALLATION
6.1 Reference Standards
The technical information and instructions provided herein below
are intended for the installer / Ser vicing Technician so that the
unit may be installed and serviced correctly and safely.
In the United Kingdom the installation and initial star t up of the
boiler must be by a CORGI Registered Installer in accordance
with the installation standards currently in eff ect, as well as with
any and all local health and saf ety standards i.e. CORGI.
In the Republic of Ireland the installation and initial start up of the
appliance must be carried out by a Competent Person in accor-
dance with the current edition of I.S .813 “Domestic Gas
Installations”, the current Building Regulations , reference should
also be made to the current ETCI rules for electrical installation.
This appliance must be installed by a competent installer in
accordance with current Gas Saf ety (installation & use)
Regulations.
The installation of this appliance must be in accordance with the
relevant requirements of the Local Building Regulations , the cur-
rent I.E.E. Wiring Regulations, the b ylaws of the local w ater
authority, in Scotland, in accordance with the Building Standards
(Scotland) Regulation and Health and Saf ety document No. 635
“Electricity at w ork regulations 1989” and in the Repub lic of
Ireland with the current edition of I.S . 813, the Local Building
Regulations (IE).
C.O.S.H.H.
Materials used in the manufacture of this appliance are non-haz-
ardous and no special precautions are required when ser vicing.
Installation should also comply with the following British Standard
Codes of Practice
The appliance ma y be installed in an y room or indoor area,
although particular attention is dr awn to the requirements of the
current I.E.E. Wiring Regulations, and in Scotland, the electr ical
provisions of the Building Regulations applicab le in Scotland,
with respect to the installation of the combined appliance in a
room containing a bath or sho wer, the location of the boiler in a
room containing a bath or sho wer should only be considered if
there is no alternative.
Where a room-sealed appliance is installed in a r oom con-
taining a bath or sho wer the appliance and an y electrical
switch or appliance contr ol, utilising mains electricity
should be situated so that it cannot be touc hed by a person
using the bath or sho wer, specifically in accor dance with
current IEE Wiring Regulations.
The location m ust permit adequate space f or servicing and air
circulation around the appliance as indicated in Section 6.4.
The location must permit the provision of an adequate flue and
termination.
For unusual locations special procedures may be necessary.
BS 6798-1987 gives detailed guidance on this aspect.
A compartment used to enclose the appliance must be designed
specifically for this purpose. No specific ventilation requirements
are needed for the installation within a cupboard.
This appliance is not suitable for outdoor installation.
The type C appliances (in whic h the combustion circuit, air
vent intake and comb ustion chamber are air -tight with
respect to the room in which the appliance is installed) can
be installed in any type of room.
Secondary ventilation is not required with this boiler . The boiler
must be installed on a solid, non-comb ustible, permanent wall to
prevent access from the rear.
BS 7593:1992 Treatment of water in domestic hot water
central heating systems
BS 5546:1990 Installation of hot water supplies for
domestic purposes
BS 5440-1:2000 Flues
BS 5440-2:2000 Air supply
BS 5449:1990 Forced circulation hot water systems
BS 6798:1987 Installation of gas fired hot water boiler s
of rated input not exceeding 60kW
BS 6891:1989 Installation of low pressure gas pipe up to
28mm
BS 7671:2001 IEE wiring regulations
BS 4814:1990 Specification for expansion vessels
BS 5482:1994 Installation of L.P.G.
6.2 Siting the Appliance

9
Installation
Legend:
A = Central Heating Flow (3/4”)
B = Domestic Hot Water Outlet (1/2”)
C = Gas Inlet (3/4”)
D = Domestic Cold Water Inlet (1/2”)
E = Central Heating Return (3/4”)
6.3 Overall Dimensions
FIG. 6.1 QT002A
FIG. 6.2 DM001B
In order to allo w access to the inter ior of the boiler f or maintenance
purposes, the boiler m ust be installed in compliance with the mini-
mum clearances indicated in FIG. 6.2
6.4 Clearances
FIG. 6.3
After removing the boiler from its packaging, remove the template
from the separate box containing the connection kit.
Note: Pay particular attention to any test water that may spill from
the appliance.
6.5 MOUNTING THE APPLIANCE
Place the template in the position the appliance is to be mounted
and after ensuring it is hanging squarely, use it to dr ill the holes
for the hanging bracket and flue pipe(s) NB: For further informa-
tion relating to the flue installation please refer to Section 6.9 Flue
Connection. (If the appliance is to be fitted on a w all of com-
bustible material, the wall must be protected by a sheet of fire-
proof material).
If the appliance is to be fitted into a timber fr amed building, guid-
ance should be sought from the IGE document REF:IGE/UP/7.

10
F
G
Fig. 6.4
TE020E
Installation
6.8 Water Connections
View of the Boiler Connections
6.5.1. Drill the wall and plug using those supplied with the con -
nections kit, position the br acket and secure with the w all
bolts supplied. Note: It is highly recommended that a spir-
it level be used to position the appliance to ensure that it is
perfectly level.
6.5.2. Position the appliance on the hanging bracket and connect
the isolating valves supplied in the connection kit as shown
on the w all template (see also Sections 6.7 Gas
Connections, 6.8 Water Connections & FIG. 6.3).
For safety purposes, have a competent person carefully chec k
the electrical system in the property, as the manufacturer will not
be held liable for damage caused by the failure to earth the appli-
ance properly or by anomalies in the supply of power. Make sure
that the residential electr ical system is adequate f or the maxi -
mum power absorbed by the unit, which is indicated on the rating
plate. In addition, check that the section of cabling is appropriate
for the power absorbed by the boiler.
The boiler operates with alter nating current, as indicated in the
Technical Information table in Section 13, where the maxim um
absorbed power is also indicated. Make sure that the connections
for the neutral and live wires correspond to the indications in the
diagram. The appliance electrical connections are situated on the
reverse of the control panel.
IMPORTANT!
In the event that the power supply cord must be changed, replace
it with one with the same specifications .
Note: The diagrams for the electrical system are indicated in sec-
tion 6.13.
Warning, this appliance must be earthed.
External wiring to the appliance must be carried out by a compe-
tent person and be in accordance with the current I.E.E.
Regulations and applicable local regulations.
The appliance is supplied with a fly-lead already connected, this
must be connected to a 240v supply fused at 3A and m ust facili-
tate complete electrical isolation of the appliance, by the use of a
fused double pole isolator having a contact separation of at least
3 mm in all poles or alternatively, by means of a 3 A fused three
pin plug and unswitched shuttered socket outlet both complying
with BS 1363.
The point of connection to the Electr icity supply must be readily
accessible and adjacent to the appliance unless the appliance is
installed in a bathroom when this must be sited outside the bath-
room (see section 6.2).
Should external controls be required, the design of the e xternal
electrical circuits should be under taken by a competent person,
see section 6.12 for further information.
6.6 Electrical Connection
6.7 Gas Connection
The local gas region contr actor connects the gas meter to the
service pipe.
If the gas supply f or the boiler ser ves other appliances ensure
that an adequate supply is a vailable both to the boiler and the
other appliances when they are in use at the same time .
Pipe work must be of an adequate siz e. Pipes of a smaller siz e
than the boiler inlet connection should not be used.
Legend:
A= Central Heating Flow
B= Domestic Hot Water Outlet
C = Gas Inlet
D = Domestic Cold Water Inlet
E = Central Heating Return
F = Safety Valve Outlet
G = Drain Valve
Pipe Work:
Copper tubing to BS EN 1057:1996 is recommended f or water
pipes. Jointing should be either with capillar y soldered or com-
pression fittings.
Where possible pipes should have a gradient to ensure air is car-
ried naturally to air release points and w ater flows naturally to
drain taps.
The appliance has a built-in automatic air release valve, however
it should be ensured as f ar 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 avoid freezing.
Particular attention should be paid to pipes passing through ven-
tilated spaces in roofs and under floors .
By-pass:
The appliance includes an automatic b y-pass valve, which pro-
tects the main heat e xchanger in case of reduced or interr upted
water circulation through the heating system, due to the closing
of thermostatic valves or radiators.
SYSTEM DESIGN:
This boiler is suitable for sealed systems only.