Viessmann SM1 Quick guide

Installation and service instructions
for contractors
VIESMANN
Solar control module
Type SM1
for wall mounting
For applicability, see the last page
Solar control module
5684 235 GB 5/2015 Please keep safe.

2
Please follow these safety instructions closely to
prevent accidents and material losses.
Safety instructions explained
Danger
This symbol warns against the risk of injury.
!Please note
This symbol warns against the risk of material
losses and environmental pollution.
Note
Details identified by the word "Note" contain additional
information.
Target group
These instructions are exclusively intended for author-
ised contractors.
■Work on gas installations must only be carried out by
a registered gas fitter.
■Work on electrical equipment must only be carried
out by a qualified electrician.
■The system must be commissioned by the system
installer or a qualified person authorised by the
installer.
Regulations to be observed
■National installation regulations
■Statutory regulations for the prevention of accidents
■Statutory regulations for environmental protection
■Codes of practice of the relevant trade associations
■All current safety regulations as defined by DIN, EN,
DVGW, TRGI, TRF, VDE and all locally applicable
standards
aÖNORM, EN, ÖVGW-TR Gas, ÖVGW-TRF and
ÖVE
cSEV, SUVA, SVGW, SVTI, SWKI, VKF and
EKAS guideline 1942: LPG, part 2
Safety instructions for working on the system
Working on the system
■Where gas is used as the fuel, close the main gas
shut-off valve and safeguard it against unintentional
reopening.
■Isolate the system from the power supply, e.g. by
removing the separate fuse or by means of a mains
isolator, and check that it is no longer 'live'.
■Safeguard the system against reconnection.
Danger
Hot surfaces can cause burns.
■Before maintenance and service work, switch
OFF the appliance and let it cool down.
■Never touch hot surfaces on the boiler, burner,
flue system or pipework.
!Please note
Electronic assemblies can be damaged by elec-
trostatic discharge.
Prior to commencing work, touch earthed
objects such as heating or water pipes to dis-
charge static loads.
Repair work
!Please note
Repairing components that fulfil a safety func-
tion can compromise the safe operation of the
system.
Replace faulty components only with genuine
Viessmann spare parts.
Auxiliary components, spare and wearing parts
!Please note
Spare and wearing parts that have not been tes-
ted together with the system can compromise its
function. Installing non-authorised components
and making non-approved modifications or con-
versions can compromise safety and may inva-
lidate our warranty.
For replacements, use only original spare parts
supplied or approved by Viessmann.
Safety instructions for operating the system
If you smell gas
Danger
Escaping gas can lead to explosions which may
result in serious injury.
■Never smoke. Prevent naked flames and
sparks. Never switch lights or electrical appli-
ances on or off.
■Close the gas shut-off valve.
■Open windows and doors.
■Evacuate any people from the danger zone.
■Notify your gas or electricity supply utility from
outside the building.
■Have the power supply to the building shut off
from a safe place (outside the building).
If you smell flue gas
Danger
Flue gas can lead to life threatening poisoning.
■Shut down the heating system.
■Ventilate the installation site.
■Close doors to living spaces to prevent flue
gases from spreading.
Safety instructions
Safety instructions
5684 235 GB

3
What to do if water escapes from the appliance
Danger
When water escapes from the appliance there is
a risk of electrocution.
Switch off the heating system by means of an
external isolator (for example fuse box, domestic
power distribution).
Flue systems and combustion air
Ensure that flue systems are clear and cannot be
sealed, for instance due to accumulation of conden-
sate or other causes. Ensure an adequate supply of
combustion air.
Instruct system users that subsequent modifications to
the building characteristics are not permissible (e.g.
cable/pipework routing, cladding or partitions).
Danger
Leaking or blocked flue systems, or an inade-
quate supply of combustion air can cause life
threatening poisoning from carbon monoxide in
the flue gas.
Ensure the flue system is in good working order.
Apertures for supplying combustion air must be
non-closable.
Extractors
Operating appliances that extract air to the outside
(cooker hoods, extractors, air conditioning units, etc.)
can create negative pressure. If the boiler is operated
at the same time, this can lead to reverse flow of the
flue gas.
Danger
The simultaneous operation of the boiler and
appliances that extract air to the outside can
result in life threatening poisoning due to
reverse flow of the flue gas.
Fit an interlock circuit or take suitable steps to
ensure an adequate supply of combustion air.
Safety instructions
Safety instructions (cont.)
5684 235 GB

4
1. Information Disposal of packaging ............................................................................ 5
Symbols ................................................................................................. 5
Intended use .......................................................................................... 5
2. Installation sequence Overview of system examples ............................................................... 6
Mounting on the wall .............................................................................. 6
Overview of electrical connections ........................................................ 7
Power supply ......................................................................................... 7
3. Commissioning Configuring the solar control module ..................................................... 9
Coding addresses overview ................................................................... 9
■Coding ................................................................................................ 9
4. Troubleshooting Faults displayed with a fault code .......................................................... 13
Errors without fault code display ............................................................ 13
Repairs .................................................................................................. 14
■Check solar circuit pump at output sF ................................................ 14
■Check connection at output sS ........................................................... 14
■Check temperature sensors ............................................................... 15
■Incorrect circulation in the solar circuit ............................................... 15
5. Parts lists Parts list ................................................................................................. 17
6. Function description Function description ............................................................................... 18
■Solar DHW heating ............................................................................. 18
■Variable speed solar circuit pump ....................................................... 18
■Suppression of DHW cylinder reheating by the heat generator ......... 19
■Suppression of reheating by the boiler in central heating backup (not
in conjunction with heat pumps) ......................................................... 19
■Maximum collector temperature ......................................................... 19
■Minimum collector temperature limit ................................................... 19
■Reduction of stagnation time .............................................................. 19
■Target temperature control ................................................................. 19
■Flow rate monitoring ........................................................................... 20
■Monitoring of night circulation (not in conjunction with heat pumps) .. 20
■Heat statement (solar yield) ................................................................ 20
■Interval function .................................................................................. 20
■Collector frost protection ..................................................................... 20
■Extended functions ............................................................................. 21
■Additional function for DHW heating ................................................... 21
■Second differential temperature control .............................................. 21
■Differential temperature control for central heating backup ................ 21
■Thermostat function ............................................................................ 21
■External heat exchanger ..................................................................... 22
■Cylinder priority control ....................................................................... 22
■Cyclical heating .................................................................................. 22
Relay kick .............................................................................................. 22
7. Specification Specification .......................................................................................... 23
Connection and wiring diagram ............................................................. 23
8. Keyword index ................................................................................................................ 25
Index
Index
5684 235 GB

5
Please dispose of packaging waste in line with statu-
tory regulations.
DE: Use the disposal system organised by
Viessmann.
AT: Use the ARA statutory disposal system (Altstoff
Recycling Austria AG, licence number 5766).
CH: Packaging waste is disposed of by the HVAC
contractor.
Symbols
Symbol Meaning
Reference to other document containing
further information
1.
Step in a diagram:
The numbers correspond to the order in
which the steps are carried out.
Warning of material losses and environ-
mental pollution
Live electrical area
Pay particular attention.
■Component must audibly click into place.
or
■Acoustic signal
■Fit new component.
or
■In conjunction with a tool: Clean the sur-
face.
Dispose of component correctly.
Dispose of component at a suitable collec-
tion point. Do not dispose of component in
domestic waste.
The work sequences for commissioning, inspection
and maintenance are summarised in the chapter
"Commissioning, inspection and maintenance "and are
marked as follows:
Symbol Meaning
Work sequences required during commis-
sioning
Not required during commissioning
Work sequences required during inspec-
tion
Not required during inspection
Work sequences required during mainte-
nance
Not required during maintenance
Intended use
The device serves to control heating systems with
solar DHW heating and solar central heating backup.
Commercial or industrial use for a purpose other than
heating the solar circuit shall be deemed inappropriate.
Intended use presupposes that a permanent installa-
tion in conjunction with permissible components
designed for this purpose has been carried out.
All other use is deemed inappropriate. Any resulting
losses are excluded from the manufacturer's liability.
Any usage beyond this must be approved by the man-
ufacturer in each individual case.
Intended use also includes adherence to maintenance
and inspection intervals.
Information
Disposal of packaging
5684 235 GB
Information

6
Oil/gas boiler
Control unit type HC1B, HO1B, HO1C,
HO2B
KW6B KC2B, KC4B, KO1B,
KO2B
System example ID ID ID
DHW heating with a dual mode DHW cyl-
inder
4605132 4605302 4605373
DHW heating and central heating backup
with a multi mode heating water buffer
cylinder
4605029
DHW heating and central heating backup
with a multi mode heating water buffer
cylinder with differential temperature con-
trol
4605160 4605409 4605376
DHW heating and central heating backup
with a heating water buffer cylinder with
freshwater module
4605030 4605410 4605411
DHW heating with 2 mono mode DHW
cylinders
4605121 4605458 4605457
DHW heating with a mono mode DHW
cylinder, and central heating backup with
a multi mode heating water buffer cylin-
der with differential temperature control
4605166 4605460 4605459
Gas adsorption heating appliance and heat pumps
Control unit type HC1D WO1C
System example ID ID
Vitosorp 200-F
DHW heating with a dual mode DHW cylinder
4605563
Vitocal 200-G
DHW heating with a mono mode DHW cylinder
4800105
Vitocal 200-S
DHW heating with a mono mode DHW cylinder
4800106
Mounting on the wall
1.
2.
Fig. 1
Installation sequence
Overview of system examples
5684 235 GB
Installation

7
% &aVG
A
[{]
PWM
L?NL
?
N
sF fÖ
M
1~
/ aÖ
L?N
M
1~
sS
230 V~
Fig. 2
ASolar control module
%Cylinder temperature sensor NTC 10 kΩ (stand-
ard delivery)
With plug %
&Collector temperature sensor NTC 20 kΩ
(standard delivery)
/Temperature sensor NTC 10 kΩ (if installed)
aÖ Temperature sensor NTC 10 kΩ (if installed)
sS Transfer pump or 3-way diverter valve
sF Solar circuit pump
fÖ Power supply
aVG KM BUS for boiler control unit
PWM Speed control, solar circuit pump (if circulation
pump with PWM control installed)
!Please note
Electronic assemblies can be damaged by elec-
trostatic discharge.
Before beginning work, touch an earthed object
such as heating or water pipes to discharge any
static.
Note
Relieve strain on-site cables.
Blank off unnecessary knockouts with cable grommets
(sealed, not cut out).
Power supply
Accessories are connected to the power supply via
plug lH on the boiler control unit.
Should the total load of the accessories exceed
400 W, then individual accessories must be connected
directly to the mains.
Danger
Incorrectly executed electrical installations can
result in injuries from electrical current and in
damage to the appliance.
Connect the power supply and implement all
safety measures (e.g. RCD circuit) in accord-
ance with the following regulations:
■IEC 60364-4-41
■VDE regulations
■Connection requirements specified by your
local power supply utility
■Protect the power cable with a fuse/MCB of up
to 16 A.
Danger
The absence of component earthing can lead to
serious injury from electric current if an electrical
fault occurs.
The appliance and pipework must be connected
to the equipotential bonding of the building.
Isolators for non-earthed conductors
■Install an isolator in the power cable to provide
omnipolar separation from the mains for all active
conductors, corresponding to overvoltage category
III (3 mm) for full isolation. This isolator must be fitted
in the permanent electrical installation, in line with
the installation requirements.
■We additionally recommend installing an AC/DC-
sensitive RCD, type B , for DC (fault) currents
that can occur with energy efficient equipment.
Installation sequence
Overview of electrical connections
5684 235 GB
Installation

8
Power supply for accessories and external compo-
nents
■For accessories and external components that will
not be connected to the control unit, we recommend
making the power connection to the same MCB/fuse,
or at the very least in-phase with the control unit.
■Connection to the same MCB/fuse provides addi-
tional safety when the power is switched off.
Observe the power consumption of the connected
consumers.
Danger
Incorrect core assignment can result in serious
injury and damage to the appliance.
Never interchange cores "L" and "N".
!Please note
Incorrect phase sequence can cause damage to
the appliance.
Check for phase equality with the control unit
power supply.
Installation sequence
Power supply (cont.)
5684 235 GB
Installation

9
The solar control module is recognised as a KM BUS
subscriber automatically by the heat generator control
unit (coding address 54).
The relevant codes for the solar control module are set
at the heat generator control unit.
Vitotronic control units for oil and gas boilers
■Weather-compensated control:
Select group "Solar".
■Constant temperature control:
Select group "4".
Vitotronic control units for heat pumps (type
WO1C)
■Select parameter group "Solar".
■In the "Type solar control unit 7A00" parameter,
select value 3.
■Invoke parameter "C0xx".
For the final two characters (xx), enter the desired
coding address from the following table.
Service instructions for the heat source or con-
trol unit
■For the required codes, see the selected system
example.
■For a function description and further details on the
coding addresses, see page 18.
Coding addresses overview
Coding
Coding in the delivered condition Possible change
Start point, solar circuit pump
00:8 Start temperature differential for
solar circuit pump 8 K.
00:2
to
00:30
Start temperature differential adjust-
able from 2 to 30 K.
Stop point, solar circuit pump
01:4 Stop temperature differential for
solar circuit pump 4 K.
01:1
to
01:29
Stop temperature differential adjust-
able from 1 to 29 K.
Speed control, solar circuit pump
02:0 Solar circuit pump is not speed-
controlled
02:1 Solar circuit pump is speed-control-
led with wave packet control
02:2 Solar circuit pump is speed-control-
led with PWM control
Differential temperature, speed control
03:10 Temperature differential for the
start of the speed control 10 K.
03:5
to
03:20
Temperature differential adjustable
from 5 to 20 K.
Controller amplification, speed control
04:4 Controller amplification of the
speed control 4 %/K.
04:1
to
04:10
Controller amplification adjustable
from 1 to 10 %/K.
Minimum speed, solar circuit pump
05:10 Min. speed of the solar circuit
pump 10 % of maximum speed.
05:2
to
05:100
Min. speed of the solar circuit pump
adjustable from 2 to 100 %.
06:75 Max. speed of the solar circuit
pump 75 % of the maximum possi-
ble speed.
06:1
to
06:100
Max. speed of the solar circuit pump
adjustable from 1 to 100 %.
Commissioning
Configuring the solar control module
5684 235 GB
Commissioning

10
Coding in the delivered condition Possible change
Interval function for capturing the collector temperature
07:0 Interval function of the solar circuit
pump switched off.
07:1 Interval function of the solar circuit
pump switched on.
To capture the collector temperature
more accurately, the solar circuit
pump periodically starts for a short
while.
Maximum cylinder temperature (set cylinder temperature)
08:60 Set DHW temperature (maximum
cylinder temperature) 60 °C.
08:10
to
08:90
Set DHW temperature adjustable
from 10 to 90 °C.
Maximum collector temperature to protect system components
09:130 Maximum collector temperature (to
protect system components)
130 °C.
09:20
to
09:200
Maximum collector temperature ad-
justable from 20 to 200 °C.
Stagnation time reduction (speed reduction, solar circuit pump)
0A:5 Temperature differential for stagna-
tion time reduction (reduction in
the speed of the solar circuit pump
to protect system components and
heat transfer medium) 5 K.
0A:0 Stagnation time reduction is disa-
bled.
0A:1
to
0A:40
Temperature differential adjustable
from 1 to 40 K.
Frost protection function, solar circuit
0b:0 Frost protection function for solar
circuit switched off
0b:1 Frost protection function for solar cir-
cuit switched on (not required with
Viessmann heat transfer medium).
Flow rate monitoring
0C:1 Flow rate monitoring active.
No flow rate captured in the solar
circuit, or flow rate too low.
0C:0 Flow rate monitoring inactive.
Night DHW circulation monitoring
0d:1 Night DHW circulation monitoring
active.
Situations with unwanted flow in
the solar circuit (e.g. at night) are
captured and relayed to the heat
source control unit.
0d:0 Night DHW circulation monitoring in-
active.
Calculation of solar yield (heat statement)
0E:1 Calculation of solar yield with
Viessmann heat transfer medium.
0E:2 Calculation of solar yield with water
as heat transfer medium (do not set,
as operation is possible only with
Viessmann heat transfer medium).
0E:0 Calculation of solar yield switched
off.
Flow rate solar circuit
0F:70 The flow rate of the solar circuit at
the maximum pump speed is set to
7 l/min.
0F:1
to
0F:255
Flow rate of the solar circuit adjusta-
ble from 0.1 to 25.5 l/min.
Target temperature control
10:0 Target temperature control inac-
tive.
10:1 Target temperature control active
(see coding address 11).
Commissioning
Coding addresses overview (cont.)
5684 235 GB
Commissioning

11
Coding in the delivered condition Possible change
Set solar cylinder temperature
11:50 Set solar DHW temperature 50 °C.
■Target temperature control active
(code "10:1"):
Temperature at which the solar
heated water is to be stratified
into the DHW cylinder.
■If code "20:9" (heating of two
DHW cylinders) is set:
when one DHW cylinder reaches
its set DHW temperature, the
second DHW cylinder is heated.
11:10
to
11:90
The set solar DHW temperature is
adjustable from 10 to 90 °C.
Minimum collector temperature
12:10 Minimum collector temperature
10 °C
(minimum start temperature for the
solar circuit pump).
12:0 Minimum collector temperature func-
tion inactive.
12:1
to
12:90
Minimum collector temperature ad-
justable from 1 to 90 °C.
Extended control functions
20:0 No extended control function ena-
bled.
Note
Extended control functions can be
used only in relation to the selec-
ted system example and the sys-
tem components listed there.
For further details regarding the
adjustable functions, see
page 21.
20:1 Additional function for DHW heating
20:2 Differential temperature control 2
20:3 Differential temperature control 2
and auxiliary function
20:4 Differential temperature control 2 for
central heating backup
20:5 Thermostat function
20:6 Thermostat function and auxiliary
function
20:7 Solar heating via external heat ex-
changer without additional tempera-
ture sensor
20:8 Solar heating via external heat ex-
changer with additional temperature
sensor
20:9 Solar heating of 2 DHW cylinders
Start temperature differential for central heating backup
22:8 Start temperature differential for
central heating backup: 8 K (code
"20:4" must be set).
22:2
to
22:30
Start temperature differential adjust-
able from 2 to 30 K.
Stop temperature differential for central heating backup
23:4 Stop temperature differential for
central heating backup: 4 K (code
"20:4" must be set).
23:1
to
23:29
Stop temperature differential adjust-
able from 1 to 29 K.
Start temperature for thermostat function
24:40 Start temperature for thermostat
function 40 °C (code "20:5" or
"20:6" must be set).
24:0
to
24:100
Start temperature for thermostat
function adjustable from 0 to 100 K.
Stop temperature for thermostat function
25:50 Stop temperature for thermostat
function 50 °C (code "20:5" or
"20:6" must be set).
25:0
to
25:100
Stop temperature for thermostat
function adjustable from 0 to 100 K.
Commissioning
Coding addresses overview (cont.)
5684 235 GB
Commissioning

12
Coding in the delivered condition Possible change
Priority DHW cylinder (cyclical heating)
26:1 Priority for DHW cylinder 1 – with
cyclical heating.
(Code "20:9" must be selected).
26:0 Priority for DHW cylinder 1 – with-
out cyclical heating.
26:2 Priority for DHW cylinder 2 – with-
out cyclical heating.
26:3 Priority for DHW cylinder 2 – with
cyclical heating.
26:4 Cyclical heating without priority for
either of the DHW cylinders
Alternate heating time
27:15 Cyclical heating time 15 min.
Once the DHW cylinder with priori-
ty is heated up, the DHW cylinder
without priority is heated for a max-
imum duration equal to the set cy-
clical heating time.
27:5
to
27:60
The cyclical heating time is adjusta-
ble from 5 to 60 min.
Alternate pause time
28:3 Cyclical pause time 3 min.
After the selected cyclical heating
time for the DHW cylinder without
priority has expired, the rise in col-
lector temperature is captured dur-
ing the cyclical pause time.
28:1
to
28:60
Cyclical pause time is adjustable
from 1 to 60 min.
Commissioning
Coding addresses overview (cont.)
5684 235 GB
Commissioning

13
The fault codes are displayed on the heat source con-
trol unit.
Fault code dis-
played
System characteristics Cause Measures
90 Control mode Short circuit, temperature
sensor /
Check sensor / at the solar con-
trol module (see page 15).
91 Control mode Short circuit, temperature
sensor aÖ
Check sensor aÖ at the solar con-
trol module (see page 15).
92 No solar DHW heating Short circuit, collector
temperature sensor &
Check sensor & at the solar con-
trol module (see page 15).
94 No solar DHW heating Short circuit, cylinder tem-
perature sensor %
Check sensor % at the solar con-
trol module (see page 15).
98 Control mode Lead break, temperature
sensor /
Check sensor / at the solar con-
trol module (see page 15).
99 Control mode Lead break, temperature
sensor aÖ
Check sensor aÖ at the solar con-
trol module (see page 15).
9A No solar DHW heating Lead break, collector tem-
perature sensor &
Check temperature sensor & at
the solar control module (see
page 15).
9C No solar DHW heating Lead break, cylinder tem-
perature sensor %
Check sensor % at the solar con-
trol module (see page 15).
9E Control mode No flow rate in solar circuit
or flow rate too low, or
temperature limiter has re-
sponded.
Check solar circuit pump and solar
circuit. Acknowledge fault mes-
sage.
9F Control mode Solar control module fault Replace solar control module.
C2 Control mode Solar control module com-
munication fault
Check solar control module.
Check setting of coding address
54: 54:3 or 54:4 must be set (sets
automatically).
EE Control mode Solar control module com-
munication fault
Check solar control module.
Check KM BUS subscriber list
("Service functions" "KM-BUS
subscriber").
Errors without fault code display
Fault Cause Remedy
Solar yield too low Temperature sensors inter-
changed.
Check temperature sensor connection. See the
relevant system example.
Air in the solar circuit Vent solar circuit and check flow rate.
Inadequate flow rate ■Check flow rate.
■Check connection of output sF (see
page 14).
Check setting of coding address 02.
■Check hydraulic connections. See the relevant
system example.
■Ensure check valves are operating correctly.
Incorrect circulation Check the system characteristics (see
page 15).
Troubleshooting
Faults displayed with a fault code
5684 235 GB
Diagnosis

14
Fault Cause Remedy
Solar circuit pump not running
or runs constantly
Temperature sensors inter-
changed.
Check temperature sensor connection. See the
relevant system example.
Check setting of coding address 20.
Solar circuit pump faulty or in-
correctly connected.
Check solar circuit pump connection (see
page 14).
Check setting of coding address 02.
Carry out a relay test.
Output sS not switched or per-
manently switched
Incorrect function configured. Check setting of coding address 20.
Solar control unit faulty. Check connection of output sS (see page 14).
Carry out a relay test.
Solar control unit switched off MCB F1 has responded. Check fuse F1. See page 23.
Disconnect consumers and reconnect in se-
quence. During this, observe the behaviour of
MCB F1.
Repairs
Check function of connected components by means of
a relay test (actuator test).
Service instructions for the heat source or the
control unit
Check solar circuit pump at output sF
Characteristics of the circulation pump (see also the
following chapter):
■Pump always off:
–High limit safety cut-out has responded. Reset the
high limit safety cut-out.
–Output sF faulty
Replace solar control module.
–Solar circuit pump faulty
Replace solar circuit pump.
■Pump always on:
–Coding address 02 incorrectly set
–PWM connection faulty
–Output sF always 'live'
Replace solar control module.
Multi stage circulation pump
In the case of stepped circulation pumps, the speed
can be changed via wave packet control.
When output sF is on, a voltage between 100 and
230 V∼ must be present.
Code 02:1 must be set.
High efficiency circulation pump or circulation
pump with inherent variable speed control
When output sF is on, a voltage of 230 V∼ must be
present.
Code 02:0 must be set.
Variable speed circulation pump with PWM control
Output sF must indicate a permanent voltage of
230 V∼. The pump speed is governed by means of a
control signal (0 - 15 V−) via connection PWM.
0 V−Pump off
8 - 15 V−Pump runs at its maximum speed
Code 02:2 must be set.
A heating circuit pump with PWM control is installed in
case the circulation pump runs at its maximum speed
when the PWM connection has been disconnected.
Heating circuit pumps with PWM control are unsuitable
for use in solar thermal systems.
Check connection at output sS
Subject to system scheme, a circulation pump or a
3-way diverter valve can be connected to output sS.
When output sS is on, a voltage of 230 V∼ must be
present.
If output sS functions correctly during the relay test but
not in normal operation, check setting of coding
address 20.
Troubleshooting
Errors without fault code display (cont.)
5684 235 GB
Diagnosis

15
Check temperature sensors
% &aVG
A
/ aÖ
Fig. 3
1. Pull plug from the respective temperature sensor
A and check the sensor resistance.
2. Compare the sensor resistance with the curve (see
the following diagram).
3. In the event of severe deviation replace the sensor.
0.1
1
10
100
0 20 40 60 80 100 120 140
Temperature in °C
Resistance in kΩ
A
B
25
Fig. 4
ACollector temperature sensor & (sensor type:
NTC 20 kΩ)
B■Cylinder temperature sensor %
■Temperature sensor /
■Temperature sensor aÖ
(sensor type: NTC 10 kΩ)
Incorrect circulation in the solar circuit
If code 0d:1 has been set (delivered condition), unwan-
ted DHW circulation (e.g. at night) will be captured. In
"Diagnosis solar" (weather-compensated control
unit) or "Brief scan" (constant temperature control
unit) the number of the captured incorrect DHW circu-
lations can be scanned.
■Check time indication at the control unit; adjust if
necessary.
■Check current collector temperature and cylinder
temperature via diagnosis.
Sensors have been interchanged if the collector tem-
perature is too low and the cylinder temperature too
high.
■Switch off all actuators via a relay test.
If the solar circuit pump continues to run, see "Check
solar circuit pump at output sF".
If the flow and return temperature rises when the
solar circuit pump is switched off, there may be re-
circulation via gravity.
Check any installed check valves or install them if
necessary.
Troubleshooting
Repairs (cont.)
5684 235 GB
Diagnosis

16
Troubleshooting
Repairs (cont.)
5684 235 GB
Diagnosis

17
The following details are required when ordering
parts:
■Serial no. (see type plate)
■Position number of the individual part within the
assembly (from this parts list)
0341 0342 0343 0344
0311
0350
0346
0345
0349
0348
0330
0347
Fig. 5
0311 Collector temperature sensor NTC 20 kΩ
0330 Solar control module SM1
0341 Power cable fÖ
0342 KM BUS cable
0343 Cylinder temperature sensor NTC 10 kΩ
0344 Solar circuit pump connecting cable
0345 Plug set, 230 V
0346 LV plug set, 2-pole
0347 MCB/fuse 4 A (slow)
0348 Plastic module casing
0349 Strain relief fittings
0350 Installation and service instructions
Parts lists
Parts list
5684 235 GB
Components

18
Note
Set or alter the functions described below in coding
levels 1 and 2 ("Solar"/4 group) at the heat source
control unit.
Service instructions for heat source or control
unit
Solar DHW heating
The solar circuit pump starts according to the following
criteria, resulting in the DHW being heated.
■The temperature differential between the cylinder
temperature and the collector temperature exceeds
the start temperature differential set in coding
address 00.
■The minimum collector temperature set in coding
address 12 has been exceeded.
The solar circuit pump will be switched off according to
the following criteria:
■The temperature differential between the cylinder
temperature and the collector temperature is smaller
than the stop temperature differential set in coding
address 01.
■The maximum cylinder temperature (set DHW tem-
perature) set in coding address 08 is exceeded.
■The maximum collector temperature set in coding
address 09 has been exceeded.
■The temperature set at the high limit safety cut-out (if
installed) is exceeded.
Variable speed solar circuit pump
The variable speed control is activated in coding
address 02 (switched off in delivered condition). It can
be activated only for relay output sF.
Possible pumps:
■Stepped solar circuit pump with speed switching via
wave packet control
■High efficiency circulation pumps or solar circuit
pumps with inherent variable speed control
■Pumps with PWM input (use solar circuit pumps
only)
Variable speed control
The speed of the solar circuit pump is controlled by
means of the temperature differential between the cyl-
inder temperature and the collector temperature (cod-
ing address 03). In the case of active target tempera-
ture control (code 10:1), the speed will also be affected
by the temperature differential between the set solar
cylinder temperature (coding address 10) and the col-
lector temperature.
The speed of the solar circuit pump is also affected by
the following settings:
■Controller amplification (coding address 04)
■Minimum speed (coding address 05)
■Minimum speed (coding address 06)
Note
Recommendation: Operate the solar circuit pump at
max. speed while the solar thermal system is being
vented.
Function description
Function description
5684 235 GB
Appendix

19
Suppression of DHW cylinder reheating by the heat generator
in systems with boilers
Reheating is suppressed in 2 stages:
■Reheating of the DHW cylinder by the boiler is sup-
pressed as soon as the DHW cylinder is heated by
the collectors. For this, the set cylinder temperature
for reheating by boiler is reduced. After the solar cir-
cuit pump has been switched off, suppression
remains active for a certain time.
■When the collectors provide continuous heating
(> 2 h):
The DHW cylinder will be heated by the boiler only if
the third set DHW temperature cannot be achieved
by the solar thermal system.
The third set DHW temperature is determined by
coding address 67 in the "DHW" group. This value
must be below the first set DHW temperature.
in systems with heat pumps
During solar DHW heating, the "DHW set tempera-
ture" is reduced by 5 K.
Suppression of reheating by the boiler in central heating backup (not in conjunction with heat
pumps)
Reheating by boiler will be suppressed if the multi
mode heating water buffer cylinder makes a sufficiently
high temperature available for heating the heating cir-
cuits.
Maximum collector temperature
If the maximum collector temperature set in coding
address 09 is exceeded, the solar circuit pump is
switched off to protect the system components (emer-
gency collector shutdown).
The solar circuit pump will restart when the collector
temperature falls to 20 K below the set value.
Minimum collector temperature limit
The solar circuit pump will start when the minimum col-
lector temperature set in coding address 12 is excee-
ded.
Reduction of stagnation time
If there is an excess of solar energy, the speed of the
solar circuit pump will be reduced before the maximum
cylinder temperature is reached (coding address 08).
This increases the differential between collector tem-
perature and cylinder temperature. The heat transfer to
the DHW cylinder is reduced, which delays stagnation.
The temperature differential designed to reduce the
stagnation time is adjustable in coding address 0A.
This function is effective only in systems with a varia-
ble speed solar circuit pump.
Target temperature control
System with one DHW cylinder
Set code 10:1 (target temperature control active).
As well as depending on the selected start tempera-
ture differential, the solar circuit pump will be started
only if the collector temperature exceeds the value set
in coding address 11.
Function description
Function description (cont.)
5684 235 GB
Appendix

20
System with 2 DHW cylinders
Set code 10:1 (target temperature control active).
Solar heating will be transferred to the second DHW
cylinder when the actual temperature of one DHW cyl-
inder has exceeded the value set in coding address
11.
Flow rate monitoring
Code 0C:1.
When, with a running solar circuit pump, the collector
temperature is >100 °C for longer than 30 min, and the
differential to the cylinder temperature is >50 K, fault
message "9E" will be issued.
Monitoring of night circulation (not in conjunction with heat pumps)
Code 0d:1.
Unwanted flow in the solar circuit (e.g. at night) is cap-
tured. For this, the collector temperature at night must
exceed the outside temperature by 10 K. The captured
situations with unwanted flow are reported to the heat
source control unit and may be scanned under "Diag-
nosis solar" (weather-compensated control unit) or by
means of a "Brief Scan" (constant temperature con-
trol unit).
Heat statement (solar yield)
When determining the amount of heat gained, the dif-
ferential between the collector and cylinder tempera-
ture, the flow rate, the type of heat transfer medium
and the operating time of the solar circuit pump are
taken into account.
For Vitodens 300-W with Vitocell 100 type CVUC-A
and Vitosolar 300-F with Vitodens 300-W, temperature
differential between solar flow and solar return is cap-
tured. For this purpose, the temperature sensors /
and aÖ are assigned to the connectors on the solar
heat exchanger.
Determine the solar circuit flow rate and set it in coding
address 0F. Each step ≙ 0.1 l/h.
In the delivered condition, coding address 0E is set to
a value of 1 (operation with Viessmann heat transfer
medium).
Interval function
Set code 07:1.
Activate the interval function in systems where the col-
lector temperature sensor is not in an ideal location, to
prevent a time delay in capturing the collector temper-
ature.
Collector frost protection
Viessmann collectors are filled with Viessmann heat
transfer medium. Consequently, this function does not
need to be enabled.
Activate only when using water as heat transfer
medium.
With a collector temperature below +5 °C, the solar cir-
cuit pump will be started to avoid damage to the collec-
tors. The pump will be stopped when a temperature of
+7 °C has been reached.
See coding address 0b.
Function description
Function description (cont.)
5684 235 GB
Appendix