Riello TAU UNIT OIL 28 B FLEX Instruction Manual

OIL 28 B
FLEX
TAU UNIT
INSTRUCTION FOR THE USER
CONDENSING BOILERS

USER
2
This manual, Code 20091445 Rev. 1 (04/17) is made up
of 20 pages.
The following symbols are used in this manual:
b = Identifies actions that require caution and
adequate preparation.
a = Identifies actions that you MUST NOT do
CONTENTS
General safety information 4
Precautions 4
Control panel 5
Mode selection 8
User levels 10
Start-up 12
Temporary shutdown 15
Preparing for extended periods of disuse 15
Cleaning 16
Maintenance 16
Useful information 17

USER 3
Dear Customer,
Thank you for choosing rTAU UNIT OIL FLEX boiler. You have purchased a modern, quality
product that is designed to give dependable and safe service and to provide comfort for many
years to come. Arrange for your boiler to be serviced regularly by r's Technical Assistance
Service. Their personnel are specially trained to keep your boiler efficient and cheap to run.
Technical Assistance Centres also stock any original spare parts that might be required.
This instruction manual contains important instructions and precautions that must be observed to
ensure the trouble-free installation and efficient functioning of your boiler.
Please accept our renewed thanks for your purchase.
Riello S.p.A.

USER
4
PRECAUTIONS
GENERAL SAFETY INFORMATION
a Do not allow children or
infirm persons to operate
the boiler unsupervised.
a Do not operate any electri-
cal devices or equipment,
including switches or domestic
appliances, etc., if you can smell
fuel or fumes. If you detect any suspicious smells:
- Ventilate the room by opening all doors and win-
dows.
- Close the fuel shut-off cock.
- Report the fault immediately to the rTechnical
Assistance Service or a professionally qualified
heating engineer.
a Never clean the boiler without first disconnecting it
from the mains electricity supply by turning the main
power switch OFF.
a Never pull, disconnect, or twist the electrical cables
coming from the boiler even if it is disconnected
from the mains electricity supply.
a Do no obstruct or restrict the vents in the room
where the appliance is installed. Adequate ventila-
tion is essential for correct combustion.
a Do not leave flammable substances or containers
in the room where the boiler is installed.
a Do not touch the boiler when
barefoot or wet.
a Do not switch the boiler off
if outside temperature drops
below ZERO (risk of freez-
ing).
b This instruction manual and that for the installer
and Technical Assistance Service are integral parts
of the boiler. They must be kept safe and must
ALWAYS accompany the boiler, even if it is sold
to another owner or user or transferred to anoth-
er installation. If you damage or lose this manual,
order a replacement immediately from your local
rTechnical Assistance Centre.
b The boiler must be installed
by a legally qualified heat-
ing engineer. On comple-
tion of the installation, the
heating engineer must
issue the owner with a
declaration of conform-
ity confirming that the
installation has been com-
pleted to the highest standards in
compliance with the instructions provided by r
in this instruction manual, and that it conforms to all
applicable laws and standards.
b If you notice any water leaking from the boiler, dis-
connect it immediately from the mains electricity
supply, shut off the water supply, and notify your
local rTechnical Assistance Centre or a quali-
fied heating engineer immediately.
b Periodically check that oper-
ating pressure in the water
circuit is over 1 bar. If water
pressure is consistently low,
contact r’s Technical
Assistance Service or a pro-
fessionally qualified heating
engineer.
b If the boiler is not going to be used for an extended
period of time, proceed as follows to prepare it for
shut-down.
- Turn the mains power switch OFF.
- Close the fuel cock and heating circuit water cock.
- Drain the central heating circuit if there is any risk
of freezing.
b The boiler must only be used for the purpose speci-
fied by rand for which it is designed. The man-
ufacturer declines all responsibility, contractual or
other, for damage to property or injury to persons
or animals caused by improper installation, adjust-
ment, maintenance or use.
The operation of any appliance that uses electrical power demands that a number of fundamental safety precautions
be respected.

USER 5
CONTROL PANEL
PRIMARY USER INTERFACE / CONTROLS
1
8-9
1017 11
732 5 64
12131516 14
8
9
18
1 - Safety thermostat trip indicator.
2 - Electronic operator unit (controller).
3 - DHW production on/off button (only present if the optional remote storage cylinder is installed). A line appears
under the "v" symbol on the display when DHW production is enabled.
4 - Display
5 - Central heating mode selection button. A line appears under the symbols:
sAUTOMATIC
oContinuous COMFORT
lContinuous REDUCED
FCOOLING
bFrost protection. The "t" symbol is displayed.
6 - Information button "i"
7 - Burner lockout indicator.
8 - Manual reset for flue gas thermostat. Unscrew the protective cover to access the reset button.
9 - Manual reset for safety thermostat. Unscrew the protective cover to access the reset button.
10 - Remote burner reset button.
11 - "p" button for chimney sweep/safety thermostat test functions
12 - "R" button for manual mode
13 - Value confirm (OK) button.
14 - Value change knob.
15 - ESCape button.
16 - PC BUS connector.
17 - Main switch.
18 - Fuse.
bottom view

USER
6
F
G
E
B
C
D
A
1
2
2
13
A - DHW mode: ON or OFF
B - Central heating modes:
sAUTOMATIC
oCONTINUOUS COMFORT
lContinuous REDUCED
FCOOLING
bFrost protection. The "t" symbol is displayed.
C - Small numeric display: time
D - Message area
E - Daily heating program indicator
F - Large numeric display: current value
G - Display symbols:
fBurner running
BChange battery (room unit only, not supplied)
wHoliday mode active
nError. Press the ibutton to display the error message.
Press ESC to return to the main screen.
C Wait: process running
hMaintenance - manual or chimney sweep mode
Reference to heating circuit
ECO Heating temporarily OFF - ECO mode active
SECONDARY USER INFORMATION / DISPLAY

USER 7
- Frost protection: The pumps are switched on on the
basis of outside temperature irrespective of demand
for heat.
If outside temperature drops below -4°C the pumps
are switched on. If outside temperature is between -5°
and 1.5°C, the pumps are switched on for 10 minutes
at intervals of 6 hours. If outside temperature is above
1.5°C the pumps are switched off.
- Chimney sweep: The burner is ignited to obtain the
conditions necessary for combustion analysis. To
obtain continuous burner functioning, maximum oper-
ating temperature is set at the boiler’s maximum set-
point.
All loads are switched off to start with, in order to bring
the boiler to its 64°C setpoint as quickly as possible.
When the boiler reaches 64°C, the heating circuits are
opened one by one to dissipate the heat and allow the
burner to continue functioning.
- Limit thermostat (parameter 2310): This function shuts
the burner down if boiler temperature exceeds the
maximum permitted limit, which coincides with the boil-
er’s maximum setpoint (parameter 2212 = 80 °C).
- DHW charging priority: if an optional remote storage
cylinder is installed and domestic hot water is drawn
off while the central heating circuit is also in use, this
function directs boiler power mainly to the DHW circuit.
- Boiler switching differential: This establishes a mini-
mum run time for the burner, to stop it igniting and
shutting down repeatedly. The burner shuts down only
if boiler temperature exceeds a predetermined thresh-
old (parameter 2240).
- Solar collector protection:
- Collector frost protection (param. 3840)
- Collector overtemperature protection (param. 3850)
- Pump protection against vapour in heat transfer fluid
(param. 3860)
G1
H1
F1
C1
D1
E1
A13B1
Boiler temperature
5
MAIN SCREEN
A1 - DHW production mode: ON or OFF.
Press the DHW button to (3) to switch DHW on or off
(as shown by the line under the symbol).
B1 - Central heating modes:
Press the central heating mode button (5) to activate the various modes as shown
by the line under the corresponding symbol.
C1 - Current time
D1 - COMFORT heating mode
E1 - Message area
F1 - Daily heating program indicator
G1 - Current boiler temperature
(If parameter 22 = “Permanently” the most recent information selected in
“Information mode” is displayed.)
H1 - Burner running
Notes on functioning
The control panel on the TAU UNIT OIL FLEX rboiler controls the following functions.

USER
8
MODE SELECTION
Domestic hot water (DHW) v
An optional remote storage cylinder must be installed
before DHW production can be enabled. Press the DHW
button (3) to activate DHW production, as shown by a line
under the corresponding symbol.
ON: DHW is generated according to the DHW time pro-
gram (parameters 560 to 566).
OFF: DHW production is switched off but the protection
functions remain active.
b You can force DHW production (PUSH function) by
pressing and holding the DHW button (3) for at least
3 seconds.
Automatic s
In automatic mode, room temperature is controlled by the time program.
Characteristics:
- Central heating operates according to the time program.
- The temperature setpoint is set to comfort "o" or reduced "l"
- All protection functions are active.
- Summer/winter switching is automatic (ECO functions) and 24h limit functions are active.
Continuous operation o or l
In continuous mode, room temperature is controlled on the basis of the comfort/reduced setting:
o Central heating set to comfort setpoint
l Central heating set to economy setpoint
Characteristics:
- Central heating is continuously on with no time program.
- All protection functions are active.
- Summer/winter switching is automatic (ECO functions) and 24h limit functions are inactive if comfort level is selected
(see parameters 730 and 732).
Protection b
In protection mode the central heating is switched off, but the system remains protected against frost (provided the
electrical supply remains switched on).
Characteristics:
- Central heating is switched off.
- Temperature is set to the frost protection setpoint.
- All protection functions are active.
- Automatic summer / winter changeover and automatic 24-hour heating limit active (ECO functions)
Press the central heating mode button (5) to select the
various modes. The active mode is shown by a line under
the corresponding symbol.
5
Boiler temperature
3
Boiler temperature

USER 9
Information i
Press the information button (6) to display:
- Errors or maintenance codes (see the “Errors/Maintenance codes” section)
- Special messages.
Other screens:
b Other screens depend on the system configuration and status. Some of the info lines shown below may not
therefore appear.
Chimney sweep mode R
When you select manual mode, the "h" symbol appears
and relays are energised/de-energised not according to
any heating program but according to a default manual
setting that can be set by pressing the information but-
ton (6).
12 11 6
Boiler temperature
- Room temperature
- Minimum room temperature
- Maximum room temperature
- Room 1 setpoint
- Room 2 setpoint
- Room 3 setpoint
- Cascade flow temperature
- Boiler temperature
- Outside temperature
- Minimum outside temperature
- Maximum outside temperature
- DHW 1 temperature
- DHW 2 temperature
- Buffer tank 1 temperature
- Buffer tank 2 temperature
- Buffer tank temperature setpoint
- Flow 1 temperature
- Flow 1 temperature setpoint
- Flow 2 temperature
- Flow 2 temperature setpoint
- Flow 3 temperature
- Flow 3 temperature setpoint
- Collector 1 temperature
- Wood fuelled boiler temperature
- Solar flow temperature
- Solar return temperature
- 24 hours solar energy yield
- Total solar energy yield
- Pool temperature
- Pool setpoint
- Heating circuit 1 status
- Heating circuit 2 status (not active)
- Heating circuit 3 status
- Cooling circuit state
- DHW status
- Boiler status
- Solar heating status
- Solid fuel boiler status
- Buffer storage tank status
- Pool state
- Error message
- Maintenance message
- Floor curing function
- Date and time
- Telephone number of technical assis-
tance centre

USER
10
USER LEVELS
There are 4 different user levels:
- End user
- Commissioning
- Heating engineer
- OEM (Manufacturer).
See the “Complete list of parameters” section for a list of
the parameters displayed in each level.
Proceed as follows to access the user level you require.
- Go to the main screen.
If necessary, press the "ESC" button one or more times
to return to the main screen.
Press the "OK" button.
Press and hold the information button "i" for 3 seconds.
- End user level. Turn the knob to scroll through the menu
until you reach the end user programming level. Press
"OK".
To enter the OEM level, you need to enter the
Password (12434).
Press the "OK". button to confirm each digit. Press "ESC"
to cancel an entry.
b - Pressing the "ESC" button takes you just one step
back: the value entered is not saved.
- If no change is made for 8 minutes, the system
returns to the main screen.
- Programming lines are displayed or hidden accord-
ing to the system configuration and the user level
(User, Commissioning, etc.).
b Parameter values on the Commissioning, Heating
engineer and OEM levels must only be changed by
the rTechnical Assistance Service.
EXAMPLE: SETTING THE CURRENT TIME
- From the main screen press "OK".
- The message area displays a number of setting pages.
Turn the knob until you reach the “Time and date” line.
Press "OK" to confirm.
Boiler temperature
End user
Commissioning
Time of day and date
Operator unit

USER 11
- The message area shows the current hour.
Press "OK".
- The display flashes the current hour. Turn the knob to go
on or back to the correct value.
Press "OK" to confirm.
- The display flashes the current minutes. Turn the knob
to go on or back to the correct value.
Press "OK" to confirm.
The new time setting is saved and the display stops
flashing. At this stage you can continue programming or
press the central heating mode button (5) to return to the
main screen.
EXAMPLE OF THE MENU STRUCTURE
Hours/minutes
Time of day and date
Ore / minuti
Ora e data
Ore / minuti
Ora e data
Ore / minuti
Ora e data
Ore / minut
i
Ora e data
Ore / minuti
Ora e data
5
Time of day and date
Heating engineer level parameters
Hours / minutes Hours 1...24 h
Operator unit Month / day Minutes 0...60 min
Time program heating circuit 1 Year
Time program 3/HCP Start summertime
Holidays heating circuit 1 End summertime
Diagnostics heat generation

USER
12
ON
OFF
START-UP
Have r’s Technical Assistance Service start-up your boiler for the first time. Once this has been done, the boiler
can be left to function automatically. Under certain circumstances, such as after long periods of disuse, the user may
need to re-start it without involving the Technical Assistance Service. Before doing so, perform the following checks and
operations:
- Check that the fuel cock and heating system water
cock are shut.
- While the system is still cold, check that the pressure
in the heating circuit is over 1 bar but below the maxi-
mum limit specified for the boiler. If water pressure is
low, contact r’s Technical Assistance Service.
- Switch the electricity supply ON at the system’s main
switch and at the control panel.
Check that the display comes on.
- When the boiler is first powered on, it performs a num-
ber of self-tests. These may take a few minutes. When
the tests are completed, the display reads out boiler
temperature.
Perform the following operations on the boiler control
panel.
- Press the "OK" button.
Select "Operator unit" and press "OK".
Select "Language" and press "OK".
Set the language you want.
SEE THE “USER PARAMETERS” MANUAL FOR
INFORMATION ON CONFIGURATION.
Boiler temperature
Time of day and date
Operator unit

USER 13
Setting the room temperature setpoint
Turn the knob (14) to set the desired room temperature
comfort setpoint.
Proceed in a similar way to set the room temperature
reduced setpoint.
- Press the "OK" button (13).
- Select “Heating circuit 1”.
- Set the room temperature reduced setpoint.
b After changing a setpoint, you need to wait about 2
hours for the new setting to have any effect on room
temperature.
b If no room unit is installed, changing the room tempera-
ture setpoint simply shifts the heating curve.
- Press the central heating mode button (5) to select
"Automatic" (b).
- If the central heating system incorporates a room unit,
check that this is active and proceed as follows to use
the knob to set the room temperature setpoint (~20°C).
- Press the “Presence” button (o/l) to display the "o"
symbol.
- Press "ESC" to return to the main screen.
- If the system is made up of a number of different heat-
ing circuits, a room temperature setpoint must be set for
each of them.
The second circuit (optional) may be either direct or
mixed.
-
Press the "OK" button.
- Select “Heating circuit 1-2-3” and press “OK”.
Set:
- the room temperature comfort setpoint
(parameters 710-1010-1310)
- the room temperature reduced setpoint
(parameters 712-1012-1312)
- the heating curve slope
(parameters 720-1020-1320).
Comfort setpoint
14
5
13
Comfort setpoint

USER
14
43,532,75 2,5 2,25
2
1,75
1,5
1,25
1
0,75
0,5
0,25
20
30
40
50
60
70
80
90
100
°C
30
40
50
60
70
80
90
100
°C
10 0-10 -20 -30 °C 20 10 0-10 -20 -30 °C
43,5 32,75 2,5 2,25
2
1,75
1,5
1,25
1
0,75
0,5
0,25
Outside temperature
Flow temperature
b Heating curve slope must only be set by the rTechnical Assistance Service.
b If no room units are installed, the room temperature setpoint set on the control panel simply performs a paral-
lel shift of the heating curves.
HEATING CURVE SLOPE
Error
30: CH flow 1 sensor
If any boiler ignition or operating errors are detected,
the "n" symbol appears on the display. Press the "Info"
(i) button to display the type of error. See also "Error/
Maintenance codes".
Only for "28/120 B" models with a remote storage
cylinder (optional)
- Press the "v" button to turn on DHW production. A line
appears under the DHW symbol.
-
Press the "OK" button.
- Select "Domestic hot water" and press "OK".
- Set:
parameter 1610 "nominal setpoint"
- To set the weekly DHW timer program, select "Time
program 4/DHW" and press "OK".
Boiler temperature
- Proceed as follows to set the weekly heating program.
-
Press the "OK" button.
- Select "Time prog heating circuit 1" and press "OK".

USER 15
TEMPORARY SHUTDOWN
PREPARING FOR EXTENDED PERIODS OF DISUSE
If you are going to be away for a short period of time like
a weekend or a short holiday, etc. proceed as follows.
- Press the central heating mode button (5) to select
"Protection" mode (b).
Power to the boiler remains switched on, and the dis-
play remains active. The fuel feed also remains open so
that the frost protection function can protect the boiler
against freezing.
Boiler frost protection: if boiler temperature falls below
5°C, the burner starts up at full power until boiler temper-
ature reaches 40°C.
Plant frost protection: This function is only active if an
outside temperature sensor is connected.
If outside temperature drops below -4°C the pumps are
switched on. If outside temperature is between -5° and
1.5°C, the pumps are switched on for 10 minutes at inter-
vals of 6 hours. If outside temperature is above 1.5°C the
pumps are switched off.
If the boiler is not going to be used for an extended peri-
od of time, proceed as follows to prepare it for shut-down.
- Turn the control panel power switch OFF and make sure
that the display goes out.
- Turn the mains power switch OFF.
- Close the fuel shut off cock and the central heating and
DHW circuit shut off cocks.
bUnder these conditions the system is not pro-
tected against frost. Drain the central heating cir-
cuit and domestic hot water circuit if there is any
risk of freezing.
ON
OFF
5
Boiler temperature

USER
16
Use a cloth damped in soapy water to clean the boil-
er’s external panelling. To remove stubborn marks, use
a cloth damped in a 50% mix of water and denatured
alcohol or a suitable cleaning product.
Wipe the boiler dry after cleaning it.
b Remove the protective film (F) from the front
panel and the control panel before you start
cleaning the boiler’s casing panels.
b The combustion chamber and flues must
be cleaned periodically by r’s Technical
Assistance Service or by a qualified heating engi-
neer.
a Do not use abrasive products, petrol or triethylene.
a Never clean or service the boiler without first dis-
connecting it from the mains electricity supply by
turning the main power switch OFF.
Please remember that THE PERSON RESPONSIBLE
FOR SYSTEM MANAGEMENT MUST ENSURE
THAT PROFESSIONALLY QUALIFIED PERSONNEL
UNDERTAKE PERIODIC MAINTENANCE AND
COMBUSTION EFFICIENCY MEASUREMENTS.
r’s Technical Assistance Service is qualified to
satisfy these legal requirements and can also provide
useful information on MAINTENANCE PROGRAMMES
designed to guarantee:
- greater safety
- compliance with applicable legislation
- freedom from the risk of fines in the event of spot
checks.
CLEANING
MAINTENANCE
F
F

USER 17
USEFUL INFORMATION
Seller: .............................................................................................................................................
Mr. .......................................................................................................................................................
Address .......................................................................................................................................
Tel. ......................................................................................................................................................
Technical Assistance Service: ....................................................................
Mr. .......................................................................................................................................................
Address .......................................................................................................................................
Tel. ......................................................................................................................................................
Fuel oil supplier: ............................................................................................................
Mr. .......................................................................................................................................................
Address .......................................................................................................................................
Tel. ......................................................................................................................................................
Installer:.......................................................................................................................................
Mr. ......................................................................................................................................................
Address ......................................................................................................................................
Tel. .....................................................................................................................................................
Date Work done
Date Quantity supplied Date Quantity supplied Date Quantity supplied Date Quantity supplied

USER
18

USER 19

RIELLO S.p.A.
Via Ing. Pilade Riello, 7
37045 - Legnago (VR)
www.riello.com
The manufacturer strives to continuously improve all products. Appearance, dimensions, technical specifi cations, standard equipment
and accessories are therefore liable to modifi cation without notice.