Operation Manual
User manual Upsilon boiler
These operation instructions describe the functioning and the operating of the 
Upsilon boilers. This manual is for the end user. For installation and servicing 
there is an installation & servicing instructions manual for the installer.
Read this manual fully before operating the boiler. In case of doubt or errors 
contact your installer. 
A.O.  Smith  reserves  the  right  to  change  the  specications  and  dimensions 
without prior notice.
Safety
The device  may  be operated  only  by  authorized  persons  who  have 
been instructed on the operation and use of the device. Improper use 
may cause damage to the device and / or to the connected installation.
The appliance is not to be used by children or persons with reduced 
physical,  sensory  or  mental  capabilities,  or  lack  of  experience  and 
knowledge, unless they have been given supervision or instructions.
Children being supervised are not to play with the appliance.
Work on the boiler must be carried out by a competent person, (Ref: 
Gas Safe Register) using correctly calibrated instruments with current 
test certication. When replacing parts use only A.O. Smith Service 
parts. Contact details for A.O. Smith can be found on the back page 
of this manual.
In case you smell gas:
-  No naked ames! Do not smoke!
-  Do not operate electrical switches for lights or any other appliance
-  Do not use a telephone
-  Turn off gas supply at meter
-  Open windows and doors
-  Notify any persons in the building and leave the building at once
-  Call Gas company or installer only when outside the building
Protection for corrosion
Do not use any sprays, chlorine containing agents, solvents, paint etc. around 
the boiler or around the air intake supply entrance of the boiler. These substan-
ces have negative inuences on the boiler and can lead to corrosion resulting 
in failure of the boiler.
Checking the water pressure
Check the water pressure in the central heating installation regularly. 
Use only potable water for lling.
Additives only after clearance by A.O. Smith.
Contact your installer in case of doubt.
Description of the boiler
The Upsilon boiler is a room sealed, condensing and modulating central heating 
boiler and meets the European requirements (CE). A declaration of conformity 
is available on demand from the supplier.
The efciency of the boiler is very high and the radiation convection and standby 
losses  very  low.  The  emission  of  noxious  substances  is  far  below  the  xed 
standards so the boiler meets the requirements of today.
If changes are made  to  the boiler construction the boiler no  longer  complies 
with the CE requirements.
Information and operation of the boiler
  Screen        User manual
T3
DHW
230V~
AC
230V
out
230V~
AC
230V
out
L
N
L
N
L
N
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 2 3 4 5 6 7 8
NN
L
N
L
P3
Error
Heat
demand
LPG
On/Off
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
T10
End
switch
Blocking
Switch
Open-
Therm
LWCO
0-10Volt
230V Pump / 3-WV.230V Damper230V DHW pump230V out230V~ AC
T4
Out
On/Off
L
MBoiC
      Keyboard   Main switch
Screen
The LCD screen is backlit. The light is activated by pushing one of the buttons 
There are 2 light colours available. The various colours indicate the following:
Blue  Basic level
Red  Problem display
Having pressed the last button, the screen light stays on for 2 minutes.
Screen explanation
       9   10 11 12  13
1                5
2                6
3                7
4                8
  1.  CH-program active
  2.  DHW-program active
  3.  Clock program active (CH and/or DHW)
  4.  Pump continuously active or pumps active when frost protection 
    is active
  5.  Boiler off at: 
    outside temperature  > T-day  (when day temperature is active)
       or   > T-night (when night temperature is active)
  6.  System pump on
  7.  Burner on. 
    Starts ashing during ignition, continuous when burner is on. 
  8.  Chimney sweep function (100% power for emission measurement)            
. ..  9.  Boiler address:
    1  = Cascade Master
    2..8  = Cascade Slaves
  10.  Identication burner inside boiler
  11.  Night temperature active
  12.  Day temperature active
  13.  2 text lines with 8 characters each
    The operational status, messages and possible errors are displayed 
    here.
Operational status
- Standby  Standby. Boiler is ready for operation.
- Vent.Phase  Ventilation stage
- Ignition phase  Ignition stage
- Burner lit CH  Burner active for heating
- Burner lit DHW  Burner active for hot water
- CH T > Tset  Burner off on account of too high ow temperature CH
- Overrun CH  Overrun time pump over CH
- Overrun DHW  Overrun time pump over DHW
- Service   Boiler needs maintenance. Contact installer
- Frost    Burner active for frost protection
Explanation keyboard
    Value increase / change
  Emission    Back / correction
  measurement
   Backward    Forward
  Reset*    Conrm selection
    Value decrease / change
* Reset
Reset only functions in case of an Error or certain Messages. If reset is 
rapidly pressed over a short period of time, the device will block comple-
tely. Only loss of power (main switch) will restart the device completely.  
Recommendation: contact your installer and inform them about the fault and 
give them the number code.
The main switch is located on the right hand side of the keyboard. This switch 
controls the 230V power supply.
Standard read-out
  Standard read-out:  Good
       we 10:17
  Good indicates that the boiler operates normally (burner on 
or off)
  we 10:17 indicates the actual day and time.
  The standard read-out offers 3 information screens. 
  Switching to different screen can be found using the + or - 
button.
  1. “Good”-read-out  Good with actual day and time 
       (see above)
  2. Operational status  Refer to the explanation of texts
       at the top of this page
  3. Technical read-out  Actual water ow
         temperature. (T1 in °C)
         and water pressure 
         (P in bar).
              See other side
R
OK
-
+
R
OK
-
+
Standby
  Good
we 10:17
 20.0 °C
1.65 bar
OK
-
+
OK
-
+
User manual
8G.52.91.03 / 04.13 Changes reserved. E.&O. E.
0310 384
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