Viessmann EM-S1 Quick guide

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5472 516 - 02 08/2021
Solar EM-S1 Extension
Installation and
Service Instructions
for use by heating contractor
ADIO electronics module
Function extension for connecting a solar thermal system
Product may not be exactly as shown
Read and save these instructions
for future reference.
IMPORTANT
Certified as a component
part for Viessmann boilers

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Please ensure that these instructions are read and understood before commencing installation. Failure to comply with
the instructions listed below and details printed in this manual can cause product/property damage, severe personal
injury, and/or loss of life. Ensure all requirements below are understood and fulfilled (including detailed information
found in manual subsections).
Product documentation
Read all applicable documentation before commencing
installation. Store documentation near boiler in a
readily accessible location for reference in the future
by service personnel.
For a listing of applicable literature,
please see section entitled “Important
Regulatory and Safety Requirements”.
Licensed professional heating contractor
The installation, adjustment, service and maintenance
of this equipment must be performed by a licensed
professional heating contractor.
Please see section entitled Safety and
“Important Regulatory and Installation
Requirements”.
Advice to owner
Once the installation work is complete, the heating
contractor must familiarize the system operator/
ultimate owner with all equipment, as well as safety
precautions/requirements, shutdown procedure, and
the need for professional service annually before the
heating season begins.
Safety
Warranty
Information contained in this and
related product documentation must
be read and followed. Failure to do
so renders the warranty null and void.
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Safety, Installation and Warranty Requirements

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3
Safety
Important Precautions
General Information
Installation
Connections
Troubleshooting
Function
Specification
Wiring
Page
Table of Contents
Page
Safety, Installation and Warranty Requirements..............2
Important Regulatory and Installation Requirements ........4
About these Installation Instructions .............................5
Intended Use .............................................................5
Spare Parts ............................................................. 5
Mounting the Solar Extension..................................... 6
Overview of Electrical Connections..............................7
Rotary Switch S1 .................................................... 8
Connecting the PlusBus to the Heat Generator ...............8
Power Supply ............................................................9
Connecting Several Accessories .................................10
Commissioning ........................................................10
Repairs .................................................................11
Faults Displayed with a Fault Code .............................12
Faults Displayed Without a Fault Code ........................12
Function Description of Solar DHW Heating .................13
Specifications ..........................................................14
Wiring Diagram ........................................................15

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Important Precautions
Important Regulatory and Installation Requirements
Approvals
Viessmann boilers, burners and controls are approved for
sale in North America by CSA International.
Codes
The installation of this unit shall be in accordance with
local codes. In the absence of local codes, use:
- CSA C22.1 Part 1 and/or local codes in Canada
- National Electrical Code ANSI/NFPA 70 in the U.S.
Always use latest editions of codes.
The heating contractor must comply with the Standard
for Controls and Safety Devices for Automatically Fired
Boilers, ANSI/ASME CSD-1 where required by the
authority having jurisdiction.
Working on the equipment
The installation, adjustment, service, and maintenance
of this product must be done by a licensed professional
heating contractor who is qualified and experienced in the
installation, service, and maintenance of hot water boilers.
There are no user serviceable parts on the boiler, burner,
or control.
Power supply
Install power supply in accordance with the regulations
of the authorities having jurisdiction or, in absence of
such requirements, in accordance with National Codes.
Viessmann recommends the installation of a disconnect
switch to the 120V power supply outside of the boiler
room.
Ensure main power supply to equipment, the heating
system, and all external controls have been deactivated.
Close main oil or gas supply valve. Take precautions in
both instances to avoid accidental activation of power
during service work.
Please carefully read this manual prior to attempting
installation. Any warranty is null and void if these
instructions are not followed.
For information regarding other Viessmann System
Technology componentry, please reference
documentation of the respective product.
We offer frequent installation and service seminars
to familiarize our partners with our products. Please
inquire.
The completeness and functionality of field supplied
electrical controls and components must be verified
by the heating contractor. These include low water
cut-offs, flow switches (if used), staging controls,
pumps, motorized valves, air vents, thermostats, etc.
WARNING
Turn off electric power supply before
servicing. Contact with live electric
components can cause shock or loss
of life.

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About these Installation Instructions
General Information
Take note of all symbols and notations intended to draw attention to potential hazards or important
product information.
CAUTION
Cautions draw your attention to the presence of potential
hazards or important product information.
WARNING
Warnings draw your attention to the presence of potential
hazards or important product information.

IMPORTANT
Indicates an imminently hazardous situation which,
if not avoided, could result in death, serious injury or
substantial product/property damage.
Indicates an imminently hazardous situation which,
if not avoided, may result in minor injury or product /
property damage.
Helpful hints for installation, operation or maintenance
which pertain to the product.
This symbol indicates to note additional information
This symbol indicates that other instructions must be
referenced.
Intended Use
Spare Parts Lists
Information about spare parts can be found at
www.viessmann.com/etapp or in the Viessmann
spare part app.
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
manufacturer in each individual case.
Intended use also includes adherence to maintenance
and inspection intervals.
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 installation
in conjunction with permissible components designed
for this purpose has been carried out.

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Installation
Mounting the Solar Extension
Extension kit for installation on a wall
1. Loosen the retaining screws from the extension kit
enclosure (do not remove).
2. Remove cover and set aside.
3. Mount the extension module enclosure to the wall
using the supplied hardware.
4. Install the cover.

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Overview of Electrical Connections
Legend
Plug 120VAC
P1sF Solar circuit pump
Only use a circulation pump with PWM control.
P3fH Transfer pump
fÖ Power supply
fÖA Power supply for accessories
Low voltage connections
PWM1 Speed control, solar circuit pump
TS1%DHW tank temperature sensor NTC 10 kΩ
TS2&Collector temperature sensor NTC 20 kΩ
TS3 No function
jF PlusBus
Note: Apply strain relief to on-site cables.
Secure individual wires directly to each plug using
cable ties.
Seal any unnecessary apertures with cable
grommets (not cut open).
CAUTION
The electronic modules are static
sensitive. To avoid damage caused by
static discharge, follow Electro-Static
Discharge safety procedures.
Connections

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Connections
Connecting the PlusBus to the Heat Generator
The rotary switch is factory preset to 0.
Note: The rotary switch can be found on the PCB of the
electronics module.
Rotary Switch S1
Legend
AExtension (electronics module)
BPlusBus to heat generator
For connection to heat generators with external
plug, luster terminals or spring-loaded terminals:
For the bus connection, disconnect plug jF. Connect
the wires directly. The wires are interchangeable.
Heat generator installation and service
instructions

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Power Supply
WARNING
The absence of component grounding in the system can
lead to serious injury from electrical current if an electrical
fault occurs. Connect the appliance and pipework to the
equipotential bonding of the building in question.
WARNING
Incorrect core allocation can result in serious injury and
damage to the appliance.
Never interchange cores “L” and “N”.
WARNING
Incorrectly executed electrical installations can result in
injuries from electrical current and in equipment damage.
Direct power supply
CAUTION
An incorrect phase sequence can cause damage
to the appliance. Check for phase equality with
the power supply connection of the control unit.
Legend
A Extension S1
Connect the power supply (see page 4) and implement
all grounding measures (e.g. RCD circuit) in accordance
with the following regulations:
HIn Canada all electrical wiring is to be done in
accordance with the latest edition of CSA C22.1 Part 1
and/or local codes. In the U.S. use the National
Electrical Code ANSI/NFPA 70. The heating contractor
must also comply with both the Standard for Controls
and Safety Devices for Automatically Fired Boilers,
ANSI/ASME CSD-1, and the Installation Code for
Hydronic Heating Systems, CSA B214-01, where
required by the authority having jurisdiction.
HConnection requirements specified by your local power
supply utility
HProtect the power cable with max. 15A
Connections

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Connecting Several Accessories
Commissioning
Configuring the solar EM-S1 extension
The parameters for the solar EM-S1 extension are set
at the heat generator control unit.
Heat generator installation and service
instructions
Connections
Power supply and PlusBus connection
In the following circumstances, use the contact
(output) of the accessories only to switch an on-site
relay:
An actuator with a higher power demand than the
fuse rating required for the accessories,
e.g. a circulation pump, is connected to the contact
(output) of the accessories.
Some accessories with direct power supply
Legend
AHeat generator control unit
BMixer extension kit for heating circuit with
mixer M2 (electronics module)
CMixer extension kit for heating circuit with
mixer M3 (electronics module)
DFurther accessories
jF PlusBus

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Repairs
Checking the solar circuit pump at output P1
Characteristics of the circulation pump (see the following
chapter):
Pump always off:
– High limit safety cut-out has responded.
Reset the high limit safety cut-out.
– Output P1 faulty
Replace extension.
– Solar circuit pump faulty
Replace solar circuit pump.
Pump always on:
– PWM connection faulty
– Output P1 always live.
Replace extension.
Variable speed circulation pump with PWM control
Whenever a demand is present, a voltage of 120VAC
must always be applied to output P1. The pump speed
is governed by means of a control signal via PWM
connection.
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 the function of the connected components by
means of an actuator test:
Heat generator installation and service
instructions
Checking the temperature sensors
1. Disconnect the plug of the relevant temperature
sensor from the extension. 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.
Legend
ACollector temperature sensor &(sensor type:
NTC 20 kΩ)
BDHW tank temperature sensor %(sensor type:
NTC 10 kΩ)
Troubleshooting

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Faults Displayed with a Fault Code
Meaning of the fault codes
Heat generator installation and service
instructions
Faults Displayed Without a Fault Code
Fault Cause Remedy
Solar yield too low Temperature sensors interchanged. 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 7).
Check hydraulic connections.
Ensure check valves are operating correctly.
Incorrect circulation Check the system characteristics.
Solar circuit pump not running
or runs constantly.
Temperature sensors interchanged. Check temperature sensor connections.
Solar circuit pump faulty or
incorrectly connected
Solar circuit pump faulty or incorrectly connected
Check solar circuit pump connection (see page 7).
Carry out an actuator test.
Solar control unit switched off Fuse F1 has responded. Check fuse F1. See page 15.
Disconnect consumers. Connect again in
sequence, and observe the behaviour of fuse F1.
Troubleshooting

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Function Description of Solar DHW Heating
Note: Set or alter the functions described below in the
parameters in the “Solar” group.
During reheating suppression, the DHW tank is only
heated by the boiler if the DHW tank temperature falls
below the set DHW temperature for reheating.
The duration of reheating suppression is based on the
runtime of the solar circuit pump and takes place in 2 stages.
Parameter Description
Number Designation
The solar circuit pump is switched on according to the following criteria, resulting in the DHW being heated:
1126.0 “Collector minimum temperature” The solar circuit pump is started when the minimum collector
temperature set in parameter 1126.0 is exceeded.
1492.0 “Start temperature differential,
solar circuit pump”
The temperature differential between the DHW tank temperature
and the collector temperature is greater than the start temperature
differential set in parameter 1492.0.
The solar circuit pump is switched off if one of the following criteria is met:
1125.0 “Maximum DHW tank temperature
for solar DHW heating”
The maximum DHW tank temperature (set DHW temperature)
set in parameter 1125.0 is exceeded.
1126.1 “Maximum collector temperature” If the maximum collector temperature set in parameter 1126.1
is exceeded, the solar circuit pump is switched off to protect the
system components (emergency collector shutdown).
The solar circuit pump will restart when the collector temperature
falls to 20 K (36°F) below the set value.
1492.1 “Stop temperature differential,
solar circuit pump”
The temperature differential between the DHW tank temperature
and the collector temperature is smaller than the stop
temperature differential set in parameter 1492.1.
-- -- The temperature set at the temperature limiter (if installed) is
exceeded.
Further parameters:
1118.0 Minimum speed of the solar circuit pump adjustable in %.
Delivered condition: 23%
1118.1 Maximum speed of the solar circuit pump adjustable in %.
Delivered condition: 84%
Start of reheating
suppression
Duration of reheating suppression Set DHW temperature for reheating by the
boiler
Stage 1
Solar circuit pump on Solar circuit pump runtime x 6
Example:
Solar circuit pump runtime: 0.5 h
0.5 h x 6 = 3 h reheating suppression
Pump runtimes that occur during the runtime of
reheating suppression are calculated according
to the formula and the result is added to the
remaining runtime of the previous reheating
suppression.
Average of the set DHW temperature and the
value set in parameter 1394.0
Example:
Set DHW temperature: 122°F (50°C)
Value set in parameter 1394.0: 104°F (40°C)
Calculated set DHW temperature for reheating
by the boiler: 113°F (45°C)
Stage 2
Solar circuit pump on
> 120 min
Runtime of the solar circuit pump + 24 h Solar circuit pump running:
Value set in parameter 1394.0
Solar circuit pump off:
As for stage 1
Suppression of DHW tank reheating by the boiler
Reheating of the DHW tank by the boiler is suppressed
when the set DHW temperature for reheating is reduced
by the boiler.

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Interval function solar circuit pump
Set parameter 1719.0.
Activate the interval function in systems where the
collector temperature sensor is not in an ideal location,
to prevent a time delay in capturing the collector
temperature.
For correct capture of the collector temperature, the
interval function cyclically switches on the solar circuit
pump for brief periods.
Relay kick
To prevent the pumps and valves from seizing up, they
are started for about 10 s every 24 h.
Function Description of Solar DHW Heating (continued)
Function/Specification
Rated voltage 120VAC
Rated frequency 60 Hz
Rated current 2A
Power consumption – electronics 2 W
Power consumption 9 mA
Permissible ambient temperature
Operation
Storage and transport
32°F to 104°F
(0°C to +40°C)
-4°F to 149°F
(–20°C to +65°C)
Rated relay output breaking
capacity
P 1 (solar circuit pump)
P 3 (transfer pump)
1A 120VAC
1A 120VAC
Reduction of stagnation time
If there is an excess of solar energy, the speed of the
solar circuit pump is reduced before the maximum DHW
tank temperature is reached (parameter 1125.0). This
causes an increase in the differential between collector
temperature and DHW tank temperature. The heat transfer
to the DHW tank is reduced, which delays stagnation.
The temperature differential for reducing the stagnation
time can be adjusted in parameter 1505.
This function can only be implemented in systems with
a variable speed solar circuit pump.
Collector frost protection
Viessmann collectors are filled with Viessmann heat
transfer medium. Consequently, this function does not
need to be enabled.
Only enable it if water is used as the heat transfer
medium.
To prevent damage to the collectors, the solar circuit
pump is switched on if the collector temperature falls
below +5°F (+5°C). The pump is switched off when
+13°F (+7°C) is reached.
Note: parameter 1127.0.
Specifications

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Connection and Wiring Diagram
Wiring Diagram
Legend
Plug 120VAC
P1 sF Solar circuit pump (only with PWM control)
P3 fH Transfer pump
fÖ Power supply
fÖA Power supply for accessories
Extra low voltage connections
PWM1 Speed control, solar circuit pump
TS1 %DHW tank temperature sensor NTC 10 kΩ
TS2 &Collector temperature sensor NTC 20 kΩ
TS3 No function
jF PlusBus
Wiring

Solar EM-S1 Extension Installation / Service
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