Best system for Greenstar 4000 GR4700iW
In UK and Ireland and have a combi boiler set up.
No separate cylinder - just straight forward combi boiler serving hot water on demand and one heating zone.
I purchased the UK/IE wireless extension kit and a few TRVs.
I then started reading up and discovered that this is not much use if I want to keep the Modulation feature of the boiler in play.
So my options are (fairly sure):
1. Replace wireless kit with wired.
2. Same thing but with Tado X.
So I want to be sure, if I go with the wired V3 kit am I safe to keep OT/BUS support or should I return everything and order the X kit.
Answers
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IIRC the Greenstar 4000 uses EMS-BUS version 2 which is not supported by Tado V3.
However Worcester Bosch does offer this: EasyControl Adapter | Worcester Bosch - which enables any controller that talks Opentherm to engage it. It should enable you to adopt a Tado system. If you already have some V3 bits, here are my thoughts:
- Looking at the wiring and installation guide for that device, it looks basically simple. However you will have to ensure your boiler is put back into EMS-BUS mode by someone who has read its installation guide. Then you have to add the EasyControl Adaptor - which is genuinely compatible with the 4000!
- You shouldnt need a wireless extension kit, just a Tado wireless stat as the primary controller.
- Contact Tado Support and ask them to give you a clear recommendation on this. If they drag their heels come back here and we'll push.
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Appreciate the reply.
I've done my own investigation and never updated here (sorry!). As this boiler uses EMS 2 (as you mention) it can't work with Opentherm devices that convert the signal that you might see available (as they convert for EMS 1 protocol or others but not 2).
Fairly sure the device you listed does the reverse of what would be needed, takes EMS2 commands from their Easy Control thermostat convertes them to OT commands for the boiler (which would be an Opentherm supporting boiler such as Baxi).
If your boiler does EMS 1 (potentially others, there seems to be a few different EMS protocols across a range of boiler manufacturers) you can buy a kit from Netherlands which should work but would void any warranty.
Additionally if you have something that works on eBUS (Ideal, Veissman boilers use this IIRC) it would be similar. There is a device that will work as a middle man (theoretically) and your Tado V3 or X could work with it - also available from Netherlands.
If you Google EMS / eBUS Opentherm converter those Netherland shops should pop up.
Finally, there are ESP32 project out there for both (just Google EMS ESP32 or eBUS ESP32) that might eventually lead somewhere or even allow a user to have simple thermostats and use that to control the boiler in NodeRED or Home Assistant etc.0 -
@SteOH. Absolutely right, my bad. I took that from an email we had with WB tech support and was given an answer which did not hold up. The latest answer, now from three seperate WB engineers, is that the Nefit Opentherm-EMS adaptor would do the job.
The requirement for Opentherm originated due to a Netherlands law mandating its use. Suppliers had to provide the interface with a full warranty. Now the published documents then state that warranties would be voided - but in the Netherlands that position was tested and the company lost. Under UK law, a vendor must provide a warranty for a minimum of one year, if its products are being used in accordance with its printed instructions. In the Netherlands the warranty voiding statement was tested and the company lost. Nobody has tested this warranty voiding assertion yet in the UK.
There are threads on this community where individuals have engaged the ESP32 project, but I've failed to understand how far they got.
As long as your boiler is serviced once a year, I dont see the risk.
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It's good to read the Nefit should do the job.
At least it's here for others to have and think over when deciding on Tado or even their boiler ha.0
