EMS device compatibility

Electrical compatibility

The EMS interface boards and the Gateways are electrically compatible with all EMS and Heatronic 3 and 4 versions. These include EMS, EMS+, EMS2, EMS Plus, Logamatic EMS, Junkers 2-wire, Heatronic 3, 4. The EMS bus is 16V.

Do not connect any EMS product to an OpenTherm bus, or a 24V or mains power thermostat bus!

EMS devices

The support for EMS devices depends on the firmware of the Gateway.

Most Bosch branded boilers that support the Logamatic EMS / Heatronic bus protocols work with this design. This includes Nefit, Buderus, Worcester, Junkers and Sieger.

Support for new devices is added with every new release. If your device is not in the list below, it might still be fully or partially compatible. If you are missing parameters you can open an issue on the code repository to get support.

The list below summarizes EMS bus devices that are supported in firmware version 1.9.4 (December 2019).

Thermostats:

  • Buderus RC10, RC20, RC20F, RC30, R35, RC300, RC310, RC3000
  • Buderus Logamatic TC100 (read-only)
  • Nefit Moduline 100, 300, 400
  • Nefit Moduline 1010, 3000 (read-only)
  • Nefit Easy (read-only)
  • Bosch CW100, Easy Control/CT200 (detected-only)
  • Junkers FR10, FR50, FR100, FR110, FW100, FW120
  • Sieger ES73

For some thermostats you cannot change the setpoint via the EMS bus. They are marked with ‘read only’.
So for these thermostats you can read the parameters, but they don’t respond to write requests.
Additionally, some of the WiFi connected thermostats don’t send any heating data over the bus, they are ‘detected-only’.

The table below is for reference only, support depends on the EMS-ESP firmware version.

ImageNameDetectedReadWriteRemarks
Buderus RC10
Nefit Moduline 100
YesYesYes
Buderus RC20
Buderus RC20RF
Nefit Moduline 200
YesYesYes
Buderus RC30
Nefit Moduline 300
YesYesYesThe Moduline 300 supports EMS but also iRT, so make sure you have an EMS boiler.
Buderus RC35
Nefit Moduline 400
YesYesYesThe Moduline 400 supports EMS but also iRT, so make sure you have an EMS boiler.
Buderus Logamatic TC100
Bosch Easy
Nefit Easy
YesYesNo
Bosch Easycontrol
CT200
YesNoNoThis thermostat does not send heating data over the EMS bus.
Buderus RC100
Nefit Moduline 1010(H)
YesYesNoThe Moduline 1010 supports both EMS and OpenTherm. Make sure your boiler is EMS!
Bosch CW100YesNoNo
Buderus RC200YesYesNo
Buderus RC300
Buderus RC310
YesYesYes
Nefit Moduline 3000YesYesNo
Bosch CW400Yes??
Junkers FR10YesYesYes
Junkers FR10
Junkers FW100
Junkers FW120
YesYesYes
Junkers FR50
Junkers FW200
Junkers FR100
Junkers FR110
Junkers FR120
YesYesNo
Sieger ES73YesYesYes

Boilers:

All EMS boilers send out the status of about 30 to 40 of its parameters to the bus every 10 to 60 seconds.
The list below gives an overview of boilers that have been tested with EMS-ESP.

  • Buderus GBx72, GB162, GB152, GB125, Logamax U122, Logamax Plus GB192, Logamax Plus GB122, Logano
  • Bosch Condens 2500
  • Worcester-Bosch Greenstar 550CDi
  • Worcester Bosch Greenstar 24i
  • Junkers Cerapur, Junkers Heatronic 3 and 4 boilers
  • Nefit Proline, Trendline, Topline, Enviline, Smartline
  • Sieger BK13 and BK15 Boiler

There are more boilers not in the list that are supported.
In general all EMS, EMS+, Heatronic 3 and Heatronic 4 boilers are supported however for some the boiler ID still has to be included in the list.

To make it easier to identify a supported boiler check if it has one of the following control panels. If so, it is likely compatible.
Some of the control panels might also include a thermostat as well.
I have not listed all possible boilers yet, so if the control panel on your boiler looks different, send me email so I can check whether it is supported.

BrandModel/RangeControllerSupportedRemarks
NefitTrendLine (II)Yes
NefitTopLineYes
NefitSmartlineYes
NefitEcomline EliteLikelyThe Elite is the only boiler from the Ecomline range with a EMS-bus UBA3. All other Ecomlines use iRT and are NOT supported.
This boiler might have a Moduline 30 thermostat connect via a RCC module. In this case the thermostat won’t be detected.
NefitBaseLineLikelyNot listed yet
BoschCondens 2500(W)Yes
BoschCondens 7000i(W)LikelyNot listed yet
BoschCondens 9000i
Condens GC9000
Yes
SiegerBK13
BK15
Yes
BuderusGB072yes
BuderusLogamax GB172yes
BuderusGB162yes
BuderusGB125yes
BuderusU122?
Buderus GB192iYes
BuderusGB212Yes
BuderusLogamax Plus GB022 Yes
WorcesterGreenstar 440CDi
Greenstar 550CDi
Yes
Worcester Greenstar 24iYes
WorcesterGreenstar 27iYesNot in the list yet
JunkersCerapur CompactLikely Not in the list yet
JunkersCerapur Smart
Cerapur Comfort
Cerapur ACU
Cerapur Modul
YesNot in the list yet
JunkersSuprapur
LikelyNot in the list yet
JunkersCerapur 4YesNot in the list yet
Cerapur MaxxYesNot in the list yet
JunkersAll with Heatronic 3 controller (ZSB, ZWB, ZWBC)Yes
JunkersAll with Heatronic 4 controllerYes

Solar Modules:

  • Buderus SM10, SM50, SM100, SM200 Solar Module
  • Junkers ISM1 Solar Module

Mixing Modules:

  • Buderus MM10, MM50, MM100, MM200 Mixer Module

Heat Pump Modules:

  • Buderus HeatPump Module
  • Nefit EnviLine

Other devices:

The devices below are detected by the Gateway but most of them do not have any useful interaction with the bus.

  • Generic Buderus MC10 Module
  • Buderus WM10 Switch Module
  • Buderus RFM20 Receiver
  • Buderus BC10, BC25, BC40 Base Controller
  • Buderus Web Gateway KM200 / MB LAN 2
  • Nefit Moduline Easy Connect
  • Bosch Easy Connect
  • EMS-OT OpenTherm converter
  • Junkers Controller

Devices that are NOT compatible

Some Bosch brands devices that are not compatible are listed below.

Non-compatible boilers

Very old Bosch brands boilers (<2007) might not be EMS based but iRT or another protocol.
Below a small selection of boilers that are known to be incompatible.

BrandModel/RangeControllerBusRemark
NefitEcomline Classic
Ecomline Excellent
Ecomline Economy
HRC23VT
UBA 1.0 / UBA 1.5 / UBA 4000 / UBA 4001iRTThermostat is often the Moduline 30.
NefitProLine NxT
ProLine Eco
OpenThermThe non-NxT ProLine is EMS!
NefitTurbo
Combi
24V on/off
JunkersSome older Junkers boilers use a CAN bus for the thermostat.With BM1 or BM2 CAN bus module.CAN busMight have a TR220 thermostat.
JunkersAll models with Heatronic or Heatronic 2.
F.i. Eurostar ZWE, ZSE, ZSBR.
3-wire bus with Junkers (PWM) 24V The thermostat is usually a TR21, TR100 or TR200.

Non-compatible thermostats

Below some thermostats that are not compatible. If you have such a thermostat, the boiler won’t be compatible as well.

ImageModelBusRemarks
Nefit Moduline IViRT
Nefit Moduline 10iRT
Nefit Moduline 20iRT
Nefit Moduline 30iRTThis thermostat was used often together with a Nefit Ecomline boiler. However, early EMS boilers sometimes also use this thermostat via so called RCC module.
Junkers TR213-wire Junkers (PWM) 24V
Junkers TR2003-wire Junkers (PWM) 24V