Unical ALKON C 24 Operation instructions

00332496 - 1st edition - 04/2008
USER’S OPERATING
INSTRUCTIONS
ALKON
18 R
24 R - 24 C -
28 R - 28 C - 35 R - 35 C
English

2
Contents
1 - SYMBOLS USED IN THIS GUIDE
When reading this guide particular care has to be given to the parts marked with the followings symbols:
NOTE!
Suggestions for the user
WARNING!
Indicates a potentially dangerous
situation for the product and the
environment
DANGER!
Indicates serious danger
for your personal safety
and for your life
2 - CORRECT USE OF THE APPLIANCE
TheALKON appliance has been designed utilizing today’s heating technology and in compliance with the
current safety regulations.
However, following an improper use, dangers could arise for the safety and life of the user or of other
people, or damage could be caused to the appliance or other objects.
The appliance is designed to be used in pumped hot water central heating systems and for domestic hot
water production.
Any other use of this appliance will be considered improper.
UNICAL declines any responsibility for any damages or injuries caused by an improper use; in this case
the risk is completely at the user’s responsibility.
In order to use the appliance according to the scopes it was designed for it is essential to carefully follow
the instructions indicated in this guide.
3 - WATER TREATMENT
• The hardness of the mains water supply conditions the frequency with which the heat exchanger is cleaned.
• In hard water areas where the main water can exceed 15°f total hardness, a scale reducing device is recom-
mended. The choice of this device has to be made taking into consideration the water’s characteristics.
• In order to improve the resistance to lime scale, it is recommended to adjust the domestic hot water temperatu-
re as near as possible to the one you really require.
• The use of a modulating room thermostat reduces the dangers of lime scale formation.
• We recommend you to check the state of cleanliness of the domestic hot water heat exchanger at the end of the
first year and subsequently, on the basis of the amount of lime scale found, this period can be extended to two
years.
CONTENTS
1Symbols used in this guide ....................................................................................................................................................... 2
2Correct use of the appliance ..................................................................................................................................................... 2
3Water treatment ......................................................................................................................................................................... 2
4Information to be handed over to the user................................................................................................................................ 3
5Safety warnings ......................................................................................................................................................................... 3
6Operating instructions ............................................................................................................................................................... 4
6.1 Control panel ...................................................................................................................................................................... 4
6.2 Check list before commissioning the boiler ....................................................................................................................... 6
6.3 Boiler operation .................................................................................................................................................................. 6
DHW production (“R” model combined with an external storage tank) ........................................................................... 6
DHW production (“C” version) ............................................................................................................................................ 6
Energizing the “pre-heat” function ..................................................................................................................................... 6
CH Mode ............................................................................................................................................................................ 6
Shutting down the boiler .................................................................................................................................................... 7
6.4 Frost protection mode ......................................................................................................................................................... 7
6.5 Eliminating the faults .......................................................................................................................................................... 7

3
General information
The user has to be instructed on the use and operation of his heating system, in particular:
• Hand over these instructions to the end user, together with any other literature regarding this appliance, placed
inside the envelope contained in the packaging. The user has to keep these documents in a safe place in
order to always have them at hand for future reference.
• Inform the user on the importance of air vents and of the flue outlet system, stressing the fact that is absolutely
forbidden to make any alterations to the boiler.
• Inform the user how to check the system’s water pressure as well as informing him how to restore the correct
pressure.
• Explain the function of time and temperature controls, thermostats, heating controls and radiators, to ensure
the greatest possible fuel economy.
• Remind the user that, in order to comply to the standards in force, it is necessary to inspect and service the
boiler according to the current codes of practice and according to the schedule indicated in this manual by the
manufacturer.
• If the appliance is sold or transferred to another owner or if the present user moves home and leaves the
appliance installed, ensure yourself that the manual always follows the appliance so that it can be consulted by
the new owner and/or installer.
Failure to follow the instructions indicated in this guide, which is supplied with the boiler, could cause
injury to persons, animals or damage to property. The manufacturer shall not be held liable for any such
injury and/or damage.
4 - INFORMATION TO BE HANDED OVER TO THE USER (BY THE INSTALLER)
5 - SAFETYWARNINGS
WARNING!
The installation, adjustment, and servicing of this appliance must be carried out by a competent person
and installed in accordance with the current standards and regulations. Failure to correctly install this
appliance could cause injury to persons, animals or damage to property. The manufacturer shall not be
held liable for any such injury and/or damage.
DANGER!
NEVER try to service or repair the appliance yourself.
All types of servicing or repairs must be carried out by a professionally qualified person, authorized by
UNICAL; UNICAL recommends drawing up a service contract.
Bad or irregular servicing could compromise the safe operation of the appliance, and could cause injury
to persons, animals or damage to property for which UNICAL shall not be held liable.
Alterations to parts connected to the appliance
Do not carry out any alterations to the following parts:
- the boiler
- to the gas, air, water feed pipes and electrical current
- to the flue pipe, safety relief valve and its drainage pipe
- to the constructive components which influence the appliance’s safe operation
Smell of gas
If you smell gas follow these safety indications:
- Do not touch any electrical switches
- Do no smoke
- Do not use the telephone
- Close the On/Off gas service cock
- Open all windows and doors where the gas leakage has occurred
- Inform the gas society or a specialized company
Explosive and easily inflammable substances
Do not use or leave explosive or easily inflammable material (as for example: petrol, paint, paper) in the room
where the appliance has been installed.

4
User’s operating instructions
6 - OPERATING INSTRUCTIONS
6.1 - CONTROL PANEL
A = Domestic hot water temperature control
B = Summer/winter selector + Central heating temperature
control knob
C = Power On indicator led(Green)
D = Central heating mode indicator led
E = Burner On indicator led(Green)
F = “RIRA” (pre-heating) mode indicator led
G = Reset /chimneysweeper mode key
H = Lock-out led indicator
I = System temperature control/pressure gauge
Summer/winter selector + Central heating
temperature control knob
By turning this knob it is possible to choose
the following operating modes:
- Summer (only DHW production)
- Winter (DHW production and central hea-
ting temperature control)
When the switch is in the (Summer)
position the central heating mode is exclu-
ded. However, the frost protection mode
remains enabled.
With the knob in the position indicated
in the figure, the boiler is in the “Winter”
mode, and controls the central heating
hot water flow temperature. The tempe-
rature can be adjusted between 30°C mi-
nimum and 80°C maximum.
Domestic hot water temperature control
NOTE!
For the Alkon R model this mode is enabled
only if the boiler is connected to an external
storage tank.
With this knob it is possible to adjust the do-
mestic hot water draw-off temperature:
By turning the knob within the range indi-
cated in the figure, it is possible to adjust
the domestic hot water temperature. The
temperature can be adjusted between 35°C
minimum and 65°C maximum (Alkon C).
The temperature can be adjusted between
25°C minimum and 60°C maximum (Alkon
R combined with external DSP storage
tank).
MAX
MIN
MAX
M
I
N
SERVICE:
MAX
MIN
B
C
A
DE F HGI

5
User’s operating instructions
Reset key with “Chimneysweeper” mode
WARNING!
This operation can be carried out exclusi-
vely by personnel from authorized After Sa-
les Service centres. The user is NOT autho-
rized to activate the following described
mode.
By pressing this key the “Chimneyswee-
per” mode is activated. This means that
the boiler will be forced to operate at the
maximum (or minimum) output so as to
permit the adjustment operations and the
combustion analysis.
By pressing this key for at least 3 seconds
the boiler will operate at the maximum ou-
tput (led D= illuminated and flashing and
led E= constantly illuminated).
By briefly pressing this key again (<3 secs.),
the boiler will operate at the minimum ou-
tput (both the leds Dand Eflashing).
The “chimneysweeper” mode will remain enabled for 15 minu-
tes.
To disenable the “CHIMNEYSWEEPER” mode before this set
time has elapsed, press the reset/chimneysweeper key “G”
for at least 3 seconds.
System temperature control/pressure gauge
This displays:
- on the upper scale the central heating
hot water flow temperature is indicated.
- On the lower scale the water pressure
in the central heating system is indica-
ted.
- If the pressure is lower then 0,7 bar, then
it will be necessary to restore the cor-
rect pressure by operating the filling
valve when the system is cold and the
boiler not operating.
Power On indicator led
This led will illuminate when the boiler is connected to
the electricity supply
Central heating mode indicator led
This led will illuminate when there is a request for cen-
tral heating. If simultaneously there is a request for
domestic hot water production, the led will switch off.
Burner On indicator led
When this led is illuminated it indicates that the burner is
functioning correctly, both in central heating request
mode and in domestic hot water production mode.
“RIRA” pre-heating function
If this function is enabled it will ensure an
immediate supply of domestic hot water.
- This function is enabled if the led (green)
is illuminated.
- This function is disenabled if the led (gre-
en) is switched off.
To enable/disenable the RIRA function
press the appropriate key.
Lock-out indicator led
When this led is illuminated it indicates that the burner’s
safety cut-off device has shut-down the boiler.
Reset key
The function of this key is to reset correct boiler ope-
ration after the cut-off device has shutdown the boi-
ler (red led indicator illuminated)
If the cut-off device operates more than 3
times, causing boiler shutdown, do not try
to reset the boiler yourself. Contact your
nearest Unical authorized After Sales Servi-
ce Centre.

6
User’s operating instructions
6.2 - CHECK LIST BEFORE COMMISSIONING
THE BOILER
Before commissioning the appliance it is recommended to
check the following points:
- Check that the On-Off gas valve, positioned upstream of
the boiler, is in the On position.
- Check that any On-Off valves fitted on the flow and return
pipes for servicing purposes are in the On position.
- Check that any On-Off valves fitted on the cold water inlet
for servicing purposes are in the On position.
- Check that the pressure relief valve drainage pipe is con-
nected to the sewage system.
- Check that the boiler is connected to the electrical supply;
the green indicator led ( ) on the control panel must be
illuminated.
- Check the heating system pressure, indicated by the pres-
sure gauge. For correct operation the pressure should be
between 0,8 and 1 bar (with the pump not running).
If the pressure falls below 0,7 bar restore the correct pres-
sure by regulating the filling valve when the system is cold
and the boiler not operating (refer to paragraph 6.5).
6.3 - BOILER OPERATION
Domestic hot water production (Alkon R + external stora-
ge tank DSP 120)
For domestic hot water production, on the R
models, it is necessary for the boiler to be
connected to an external storage tank, as for
example the DSP.
Position the domestic hot water control
knob (A) to the desired DHW temperature:
- with the knob turned completely to the
left = 25°C
- with the knob turned completely to the ri-
ght = 60°C
Note:
By adjusting the DHW temperature at a tem-
perature very close to the one actually used
will avoid mixing hot water with cold water,
thus resulting in fuel savings and a significant
reduction in lime scale formation.
In this case, the boiler will fire until the water contained in the
tank has reached the desired temperature, set via the knob
“A” .
When a tap or shower is turned on the appliance will provide
domestic hot water at the desired temperature.
Domestic hot water production (Alkon “C” model)
Position the domestic hot water control knob
(A) to the desired DHW temperature:
- with the knob turned completely to the left
= 35°C
- with the knob turned completely to the ri-
ght = 65°C
Note:
By adjusting the DHW temperature at a tem-
perature very close to the one actually used
will avoid mixing hot water with cold water,
thus resulting in fuel savings and a significant
reduction of lime scale formation.
When a tap or shower is turned on the appliance will provide
domestic hot water at the desired temperature
Enabling and disenabling the “RIRA” pre-heating function
(only on the Alkon C model)
This function can be enabled/disenabled by
pressing this key.
Green led On > RIRA function enabled
Green led Off > RIRA function disenabled.
If this function is enabled it will guarantee an immediate sup-
ply of domestic hot water.
Central heating mode
The boiler will operate in the CH mode
when the knob (B) is positioned within
the range indicated in the figure.
- with the knob in the position 1, the mi-
nimum temperature corresponds to >
35°C.
- with the knob in the position 2, the
maximum temperature corresponds to
>80°C.

7
User’s operating instructions
SHUTTING DOWN THE BOILER
To disenable the CH mode
Turn the knob (B) completely to the left to
disenable the CH mode. The DHW mode
however remains enabled (SUMMER
mode).
Complete boiler shut down
If the boiler is completely shut down, the CH and DHW mode
will be completely disenabled.
To completely shut down the boiler, switch off the electrical
supply to the boiler (the green “Power On” led is not illumi-
nated).
If the boiler will remain shut down for a longer period, turn the
On/Off gas cock into the Off position and, if fitted, turn the cold
water supply cock into the Off position.
6.4 - FROST PROTECTION MODE
The boiler is fitted with a frost protection system which will
operate automatically when the system temperature falls be-
low 6°C: the burner is automatically fired and the pump is ener-
gized until the system’s water temperature has risen to 16°C.
If the temperature detected by the CH sensor falls below 2°C,
burner operation is automatically stopped until the temperatu-
re has risen to 5°C.
WARNING!
This feature will operate only if the electrical
supply to the boiler is On (green Power On led
illuminated).
However, further frost protection can be incor-
porated by using specific frost protection pro-
ducts, suitable for multi-metal systems. Do not
use anti-frost products for motor vehicles
because they could seriously damage the
water gaskets.
If, for any reason, there is no gas or electrical
supply, the above described frost protection
mode will not be active.
Cause:
Insufficient water pressure in the central heating system.
Elimination of the fault:
Restore the correct pressure value by regulating the boiler’s
filling valve (for correct boiler operation the pressure should
be between 0,8 and 1 bar).
When the correct pressure value has been reached the led
will switch off automatically and normal boiler operation will be
restored.
DANGER!
If the system has to be frequently restored
please contact an authorized Unical After
Sales Service Centre.
Burner lock-out led constantly illuminated
Cause:
IThe burner’s lock-out device has intervened due to:
- no gas supply (in this case check that the gas service cock
is open
- presence of air in the piping (if it is a new system or after a
long inactivity of the boiler).
Elimination of the fault:
Check that the gas service cock is in the On position and that
the air present in the piping has been vented.
Press the reset key to restore correct boiler operation.
If the cut-off device operates repeatedly (a
maximum of 3 times), causing boiler shu-
tdown, do not try to relight the boiler your-
self. Contact your nearest Unical authorized
After Sales Service Centre.
Filling
cock
Open
Close
6.5 - ELIMINATING THE FAULTS
If the boiler goes into lock-out the user can reset the boiler
only in the following cases:
Lock-out led illuminated and flashing
WARNING:
If the boiler goes into lock-out and/or the
leds continue to flash repeatedly or remain
illuminated do not try to reset the boiler your-
self. Contact your nearest Unical authorized
Afters Sales Service Centre.

The Unical declines every responsibility for the possible inaccuracies if owed to errors of transcript or press. Also reserves the right
to bring those changes that it will hold necessary to it own products or profits, without jeopardizing its essential characteristics.
AG S.P.A.
46033 casteldario - mantova - italia - tel. [phone] (r.a.) - fax [phone]
www.unical.ag - [email protected]