Viessmann SDIO/SM1A Quick guide

Installation and service instructions
for contractors
VIESMANN
SDIO/SM1A electronics module
■In conjunction with the Vitotronic control unit and HMU control unit
■For controlling and regulating a solar DHW heating system
SDIO/SM1A electronics module
5838676 GB 2/2019 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 quali-
fied contractors.
■Work on gas installations may only be carried out by
a registered gas fitter.
■Work on electrical equipment may 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
■Relevant country-specific safety regulations
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.
■Wear suitable personal protective equipment when
carrying out any work.
Danger
Hot surfaces and fluids can lead to burns or
scalding.
■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
Safety instructions
5838676

3
Safety instructions for operating the system
If you smell gas
Danger
Escaping gas can lead to explosions which may
result in serious injury.
■Do not 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.
What to do if water escapes from the appliance
Danger
If water escapes from the appliance there is a
risk of electrocution.
Switch OFF the heating system at the external
isolator (e.g. fuse box, domestic distribution
board).
Danger
If water escapes from the appliance there is a
risk of scalding.
Never touch hot heating water.
Condensate
Danger
Contact with condensate can be harmful to
health.
Never let condensate touch your skin or eyes
and do not swallow it.
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 external causes.
Ensure an adequate supply of combustion air.
Inform 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.
Vents for supplying combustion air must be non-
sealable.
Extractors
Operating appliances that exhaust air to the outside
(extractor hoods, extractors, air conditioning units, etc.)
can create negative pressure. If the boiler is operated
at the same time, this can lead to a reverse flow of flue
gas.
Danger
The simultaneous operation of the boiler and
appliances that exhausts air to the outside can
result in life threatening poisoning due to a
reverse flow of flue gas.
Fit an interlock circuit or take suitable steps to
ensure an adequate supply of combustion air.
Safety instructions
Safety instructions (cont.)
5838676

4
1. Information Disposal of packaging ............................................................................ 5
Symbols ................................................................................................. 5
Intended use .......................................................................................... 5
System examples .................................................................................. 6
2. Installation sequence Overview of electrical connections ........................................................ 7
Power supply ......................................................................................... 8
3. Commissioning Configuring the SDIO/SM1A electronics module ................................... 9
■Automatic detection ............................................................................ 9
■Changing the configured bus system ................................................. 9
■Adjusting the codes/parameters ......................................................... 9
■Overview of coding addresses (only with SM1 and KM-BUS) ............ 9
4. Troubleshooting Faults displayed with a fault code .......................................................... 15
Errors without fault code display ............................................................ 15
Repairs .................................................................................................. 15
■Check solar circuit pump at output sF ................................................ 16
■Check connection at output sS ........................................................... 16
■Check temperature sensors ............................................................... 16
■Incorrect circulation in the solar circuit ............................................... 17
5. Parts lists Parts list ................................................................................................. 19
6. Function description Version with SM1 and KM-BUS ............................................................. 22
■Solar DHW heating ............................................................................. 22
■Variable speed solar circuit pump ....................................................... 22
■Suppression of DHW cylinder reheating by the heat generator ......... 23
■Suppression of reheating by the boiler in relation to central heating
backup (not in conjunction with heat pumps) ..................................... 23
■Maximum collector temperature ......................................................... 23
■Minimum collector temperature limit ................................................... 23
■Reduction of stagnation time .............................................................. 24
■Target temperature control ................................................................. 24
■Flow rate monitoring ........................................................................... 24
■Monitoring of night circulation (not in conjunction with heat pumps) .. 24
■Heat statement (solar yield) ................................................................ 24
■Interval function .................................................................................. 25
■Collector frost protection ..................................................................... 25
■Extended functions ............................................................................. 25
■Additional function for DHW heating ................................................... 25
■Differential temperature control 2 ....................................................... 25
■Differential temperature control for central heating backup ................ 26
■Thermostat function ............................................................................ 26
■External heat exchanger ..................................................................... 26
■Cylinder priority control ....................................................................... 26
■Cyclical heating .................................................................................. 27
Version with SDIO/SM1A electronics module and PlusBus ................... 27
■Solar DHW heating ............................................................................. 27
Relay kick .............................................................................................. 28
7. Specification Specification .......................................................................................... 29
Connection and wiring diagram ............................................................. 29
8. Disposal Final decommissioning and disposal ..................................................... 31
9. Declaration of Conformity ................................................................................................................ 32
10. Keyword index ................................................................................................................ 33
Index
Index
5838676

5
Please dispose of packaging waste in line with statu-
tory regulations.
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 steps in connection with commissioning, inspec-
tion and maintenance are found in the "Commission-
ing, inspection and maintenance" section and identified
as follows:
Symbol Meaning
Steps required during commissioning
Not required during commissioning
Steps required during inspection
Not required during inspection
Steps required during maintenance
Not required during maintenance
Intended use
The device serves to control heating systems with
solar DHW heating.
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
5838676
Information

6
For available system examples, see www.viessmann-
schemes.com
Information
System examples
5838676
Information

7
Danger
Incorrect wiring can lead to serious injury from
electrical current and result in appliance dam-
age.
■Route extra low voltage (ELV) leads < 42 V
and > 42 V/230 V~ cables separately.
■Only strip the minimum of insulation from
cables as close as possible to the terminals
and bundle tightly to the corresponding termi-
nals.
■Secure cables with cable ties.
% &aVG [{]
PWM
? ?
sF fÖ
M
1~
/ aÖ
?
M
1~
sS
230 V∼
jF
NTC NTC 50 Hz
10 kΩ 20 kΩ
A
NTC NTC
10 kΩ 10 kΩ
F1 T2A
Fig. 1
ASDIO/SM1A electronics 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
jF PlusBus for connecting with HMU control unit,
DIO electronics module or ADIO electronics
module
aVG KM-BUS to Vitotronic boiler control unit
PWM Speed control, solar circuit pump (if circulation
pump with PWM control installed)
!Please note
Electronic assemblies can be damaged by static
loads.
Before beginning work, touch an earthed object
such as a heating or water pipe to discharge any
static.
Note
Apply strain relief to on-site cables.
Seal any unnecessary apertures with cable grommets
(not cut open).
Installation sequence
Overview of electrical connections
5838676
Installation

8
Connecting heat generator accessories to a power
supply
■Oil or gas boiler:
Plug lH or aBH on the Vitotronic boiler control
unit/HMU control unit:
Observe max. connected load of all accessories
(400 W). If required, connect the SDIO/SM1A elec-
tronics module directly to the mains supply: See
installation and service instructions for the boiler or
the Vitotronic control unit.
■Heat pumps:
Terminal X3.1 on the cross connect PCB or at the
luster terminals:
Observe max. connected load of the heat pump con-
trol unit. If required, connect the SDIO/SM1A elec-
tronics module directly to the mains supply: See
installation and service instructions for the heat
pump.
Danger
Incorrectly executed electrical installations can
result in injuries from electrical current and dam-
age 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
■TAR medium voltage VDE-AR-N-4110
■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. This should correspond to overvoltage
category III (3 mm) for full isolation. The isolator
must be fitted in the permanent electrical installation,
in line with installation requirements.
■We additionally recommend installing an AC/DC-
sensitive RCD, type B , for DC (fault) currents
that can occur with energy efficient equipment.
Power supply for accessories and external compo-
nents
■Recommendation: For accessories and external
components that are not connected to the control
unit, make the power connection to the same MCB/
fuse. At the very least, connect them in phase with
the control unit.
■Connection to the same MCB/fuse provides addi-
tional safety in the event of the power being switched
off. Observe the power consumption of the connec-
ted 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.
Ensure phase equality with the control unit
power supply.
Installation sequence
Power supply
5838676
Installation

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Automatic detection
The SDIO/SM1A electronics module is automatically
detected as a KM-BUS subscriber (SM1A) or PlusBus
subscriber (HMU control unit).
In order for the bus system to be detected, it needs to
have been connected at the time of the initial commis-
sioning.
Once the bus system has been detected, it remains
stored even after disconnection from the mains. When
restarting, it starts with the same bus system.
Changing the configured bus system
1. Remove the bus connection and all sensor con-
nections
2. With no other connections, connect the SDIO/
SM1A electronics module to mains voltage only
and switch on.
The LED on the top left of the PCB flashes for 1
minute.
After 1 minute, the LED lights up permanently. The
SDIO/SM1A electronics module is now reset to the
factory setting.
3. Restart the SDIO/SM1A electronics module as
described above. In the process, the connected
bus system will be detected.
The next commissioning process then corresponds
to initial commissioning as described above.
Adjusting the codes/parameters
The codes/parameters for the SDIO/SM1A electronics
module are set at the heat generator control unit.
Service instructions for the heat generator or the
Vitotronic control unit
Vitotronic control units for heat pumps (type
WO1C)
Service instructions for the Vitotronic 200, type
WO1C
1. At coding level 1 call up parameter group "Solar".
2. Set parameter "Type solar control unit 7A00" to
"3".
3. Invoke parameter C0xx.
4. In the two last places (xx) of the parameter
"C0xx", enter the required coding address.
Note
xx corresponds to coding addresses "00:..." to
"28:...".
Heat generator with PlusBus data cable (plug 74)
Relevant parameters:
Installation and service instructions for the
respective heat generator
Note
For a function description and further details on coding
addresses: See page 22.
Overview of coding addresses (only with SM1 and KM-BUS)
If using the SDIO/SM1A electronics module in conjunc-
tion with PlusBus (plug jF), the parameters are listed
in the installation and service instructions for the heat
generator.
Heat generator installation and service instruc-
tions
Commissioning
Configuring the SDIO/SM1A electronics module
5838676
Commissioning

10
Note
Parameter values in bold are factory settings.
00 Start temperature differential, solar circuit pump
Display Value Explanations
8 K 00:8
... K 00:2 to
00:30
01 Stop temperature differential, solar circuit pump
Display Value Explanations
4 K 01:4
... K 01:1 to
01:29
02 Speed control, solar circuit pump
Display Value Explanations
Without 02:0 Without speed control
Do not adjust 02:1
With PWM control 02:2 With PWM control
Note
Changed display on Vitotronic 200 heat pump control
unit, type WO1C: "Speed control solar circuit
pump"
03 Temperature differential for start of speed control
Display Value Explanations
10 K 03:10
... K 03:5 to
03:20
04 Controller amplification of speed control
Display Value Explanations
4 %/K 04:4
... %/K 04:1 to
04:10
Controller amplification adjustable from 1 to 10 %/K
05 Min. speed, solar circuit pump
Display Value Explanations
10 % 05:10 Min. speed of the solar circuit pump 10 % of max.
speed
... % 05:2 to
05:100
Commissioning
Configuring the SDIO/SM1A electronics module (cont.)
5838676
Commissioning

11
06 Max. speed, solar circuit pump
Display Value Explanations
75 % 06:75 Maximum speed of solar circuit pump 75 % of max.
speed
... % 06:2 to
06:100
07 Interval function, solar circuit pump
Display Value Explanations
OFF 07:0 Interval function of solar circuit pump switched off
ON 07:1 To capture the collector temperature more accurately,
the solar circuit pump periodically starts for a short du-
ration.
08 Maximum cylinder temperature
Display Value Explanations
60 °C 08:60 Set DHW temperature (maximum cylinder tempera-
ture) 60 °C
... °C 08:10 to
08:90
09 Maximum collector temperature
Display Value Explanations
130 °C 09:130 Maximum collector temperature (to protect system
components) 130 °C
... °C 09:20 to
09:200
0A Stagnation time reduction
Display Value Explanations
Temperature differential for stagnation time reduction:
Reduction in the speed of the solar circuit pump to
protect system components and heat transfer medium
None 0A:0 Stagnation time reduction not active
5 K 0A:5
... K 0A:1 to
0A:40
0B Frost protection function for solar circuit
Display Value Explanations
OFF 0B:0
ON 0B:1 Not required in conjunction with Viessmann heat
transfer medium
Commissioning
Configuring the SDIO/SM1A electronics module (cont.)
5838676
Commissioning

12
0C Delta T monitoring
Display Value Explanations
OFF 0C:0
ON 0C:1 No flow rate captured in the solar circuit, or flow rate
too low.
0D Night DHW circulation monitoring
Display Value Explanations
OFF 0D:0
ON 0D:1 Unintentional flow rate in the solar circuit (e.g. at
night) is captured.
0E Calculation of solar yield
Display Value Explanations
OFF 0E:0
Calculation of solar yield with Viessmann
heat transfer medium
0E:1
Calculation of solar yield with water as heat
transfer medium
0E:2 Do not adjust
0F Flow rate, solar circuit at max. pump speed
Display Value Explanations
7 l/min 0F:70
... l/min 0F:1 to
0F:255
Flow rate adjustable from 0.1 to 25.5 l/min
1 step ≙ 0.1 l/min
10 Target temperature control
Display Value Explanations
OFF 10:0
ON 10:1 See parameter "11"
11 Set DHW temperature, solar
Display Value Explanations
■Target temperature control is switched on (parame-
ter "10:1"):
Temperature at which the solar heated water is to be
stratified into the DHW cylinder.
■Heating of 2 DHW cylinders is set (parameter
"20:9"):
When the set cylinder temperature is achieved in
one DHW cylinder, the 2nd DHW cylinder is heated.
50 °C 11:50
... °C 11:10 to
11:90
Set solar cylinder temperature adjustable from 10 to
90 °C.
Commissioning
Configuring the SDIO/SM1A electronics module (cont.)
5838676
Commissioning

13
12 Minimum collector temperature
Display Value Explanations
None 12:0 Minimum temperature limit disabled
10 °C 12:10 Minimum start temperature for solar circuit pump
10 °C
... °C 12:1 to
12:90
20 Extended control function
Display Value Explanations
None 20:0 No extended control function enabled
Additional function, increased DHW hy-
giene
20:1
Differential temperature control 2 20:2 Do not adjust in conjunction with Vitocell 100-W, type
CVUB-A
Differential temperature control 2 and auxil-
iary function for increased DHW hygiene
20:3 Do not adjust in conjunction with Vitocell 100-W, type
CVUB-A
Differential temperature control 2 for central
heating backup
20:4 Do not adjust in conjunction with Vitocell 100-W, type
CVUB-A
Thermostat function 20:5 Do not adjust in conjunction with Vitocell 100-W, type
CVUB-A
Thermostat function and auxiliary function
for increased DHW hygiene
20:6 Do not adjust in conjunction with Vitocell 100-W, type
CVUB-A
Solar heating via external heat exchanger
without additional temperature sensor
20:7
Solar heating via external heat exchanger
with additional temperature sensor
20:8 Do not adjust in conjunction with Vitocell 100-W, type
CVUB-A
Solar heating of 2 DHW cylinders 20:9 Do not adjust in conjunction with Vitocell 100-W, type
CVUB-A
Note
Changed display on Vitotronic 200 heat pump control
unit, type WO1C: "Extended solar control func-
tions"
22 Start temperature differential for central heating backup
Display Value Explanations
Parameter "20:4" must be set.
8 K 22:8
... K 22:2 to
22:30
23 Stop temperature differential for central heating backup
Display Value Explanations
Parameter "20:4" must be set.
4 K 23:4
... K 23:1 to
23:29
Commissioning
Configuring the SDIO/SM1A electronics module (cont.)
5838676
Commissioning

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24 Start temperature for thermostat function
Display Value Explanations
Parameter "20:5" or "20:6" must be set.
40 °C 24:40
... °C 24:0 to
24:100
25 Stop temperature for thermostat function
Display Value Explanations
Parameter "20:5" or "20:6" must be set.
50 °C 25:50
... °C 25:0 to
25:100
26 Priority for DHW cylinder
Display Value Explanations
Parameter "20:9" must be set.
Priority for DHW cylinder 1 – without cycli-
cal heating
26:0
Priority for DHW cylinder 1 – with cyclical
heating
26:1
Priority for DHW cylinder 2 – without cycli-
cal heating
26:2
Priority for DHW cylinder 2 – with cyclical
heating
26:3
Cyclical heating without priority for any of
the DHW cylinders
26:4 Cyclical heating without priority for one of the DHW
cylinders
27 Cyclical heating time
Display Value Explanations
The DHW cylinder with priority is heated first. Then
the DHW cylinder without priority is heated for a max-
imum duration equal to the set cyclical heating time.
15 min 27:15
... min 27:5 to
27:60
28 Cyclical pause time
Display Value Explanations
After the set cyclical heating time for the DHW cylin-
der without priority has expired (parameter "27"), the
rise in collector temperature is captured during the cy-
clical pause time.
3 min 28:3
... min 28:1 to
28:60
Commissioning
Configuring the SDIO/SM1A electronics module (cont.)
5838676
Commissioning

15
Fault codes
Service instructions for the heat generator or the
Vitotronic control unit
Errors without fault code display
Fault Cause Remedy
Solar yield too low Temperature sensors inter-
changed.
Check temperature sensor connections.
Air in the solar circuit Vent the solar circuit. Check flow rate.
Inadequate flow rate ■Check flow rate.
■Check connection of output sF (see
page 16).
Check coding address "02".
■Check hydraulic connections.
■Ensure check valves are operating correctly.
Incorrect circulation Check the system characteristics (see
page 17).
Solar circuit pump not running
or runs constantly.
Temperature sensors inter-
changed.
Check temperature sensor connections.
Check coding address "20".
Solar circuit pump faulty or in-
correctly connected
Check solar circuit pump connection (see
page 16).
Check coding address "02".
Carrying out a relay/actuator test.
Output sS not switched or per-
manently switched.
Incorrect function configured Check setting of coding address "20".
SDIO/SM1A electronics mod-
ule fault
Check connection of output sS (see page 16).
Carrying out a relay/actuator test.
Solar control unit switched off MCB F1 has responded. Check fuse F1. See page 29.
Disconnect consumers. Connect again in se-
quence. During this, observe the behaviour of
MCB F1.
Repairs
Check function of connected components by means of
a relay/actuator test:
Service instructions for the heat generator or the
Vitotronic control unit
Troubleshooting
Faults displayed with a fault code
5838676
Diagnosis

16
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 the SDIO/SM1A electronics 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 the SDIO/SM1A electronics module.
Multi stage circulation pump
The multi stage circulation pump is switched on and off
via output sF.
Code/parameter "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 via PWM connection.
Code/parameter "02:2" must be set.
If the PWM connection is interrupted the circulation
pump must be switched off. If the circulation pump
runs at maximum speed when the PWM connection is
interrupted, an incorrect circulation pump has been
installed.
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/actua-
tor test but not in normal operation, check setting of
coding address "20".
Check temperature sensors
NTC NTC
10 kΩ 20 kΩ
% &aVG
A
/ aÖ
jF
NTC
10 kΩ
NTC
10 kΩ
Fig. 2
1. Pull plug of relevant temperature sensor from
SDIO/SM1A electronics module 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.
Troubleshooting
Repairs (cont.)
5838676
Diagnosis

17
0.1
1
10
100
0 20 40 60 80 100 120 140
Temperature in °C
Resistance in kΩ
A
B
25
Fig. 3
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/parameter "0D:1" has been set (delivered con-
dition), unwanted DHW circulation (e.g. at night) is
captured. In "Diagnosis solar" (weather-compensa-
ted control unit) or "Brief scan" (constant temperature
control unit), the number of instances where incorrect
circulation was captured can be scanned.
■Check time shown at the control unit; adjust if neces-
sary.
■Check current collector temperature and cylinder
temperature via diagnosis.
If the collector temperature is too low and the cylin-
der temperature too high, then the sensors have
been interchanged.
■Switch off all actuators via a relay/actuator 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.)
5838676
Diagnosis

18
Troubleshooting
Repairs (cont.)
5838676
Diagnosis

19
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)
Parts lists
Parts list
5838676
Components

20
0004 0010 0011
0012
0001
0003
0005 0006
0007 0008 0009
Fig. 4
Parts lists
Parts list (cont.)
5838676
Components