Worcester Bosch Greenstar 8000 and EMS
Hi,
I have a Worcester Greenstar 8000 boiler installed in an S-Plan system.
On the Tado side have a Wireless Extension Kit and use a combination of TRVs and a Wireless temperature sensor. I'm also using a Mixergy hot water cylinder.
I'm planning to have an internal diverter valve installed in the boiler so that I can control the heating and hot water flow temperatures independently. This would result in the zone valves being removed, so the Wireless Extension unit becomes redundant and a Wired Thermostat could be used.
Reading the forums, there seems to be a lot of mixed information about the Greenstar 8000 system boiler. It has an EMS port, which I've confirmed via the boiler documentation.
If and when it des support this boiler model, should I use the Wired Thermostat model to interface with it? As I won't have zone valves, I believe the Wireless Extension becomes redundant.
Can anyone in Tado support confirm that the Greenstar 8000 Life system boiler isn't supported via the EMS interface? If not, when do you expect it might be supported?
Answers
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I too would like to know whether the Greenstar 8000 Life system boiler is currently or will be supported via the EMS interface.
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I received a reply tado° today that "tado° is not currently compatible with EMS control of the Greenstar 8000 Life.
They had no information on it being supported in future and suggested raising a request here: leave your feature request in the tado° Community
Or you could add your votes to an existing request I found here: https://tado.vanillacommunities.com/en-gb/discussion/9230/support-newer-version-of-worcester-ht-bus
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I abandoned home support a long while ago. I think WB want to see their own thermostats. I’ve been using this https://bbqkees-electronics.nl/product/gateway-s32-standard-edition/ in conjunction with Home Assistant to adjust the heat requirements of the boiler. Happy to share more info if you wish.0
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I would be grateful for more info as I could not find any reference to the Greenstar 8000 Life on that site. I just discovered that Shelly make TRV, so this may be a way to achieve BUS control of the boiler that can be integrated with 2 zone valves & an UFH pump.
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I bought a Nefit (owned by Bosch) OT to EMS converter from this shop:
https://www.robbshop.nl/nefit-ems-opentherm-converter?sqr=ems
It was easy to fit, the Tado wired thermostat needed to be set to “Various, Opentherm” (look for Tado Installer app for configure details) and now the boiler appears to be modulating. It seems to be unidirectional, so no boiler status info available in the Tado app, but that’s fine.1 -
An update from my Sept 13 post. I installed an EMS Bus gateway to monitor the WB Greenstar 8000, and to download graphs into Home Automation.
What I've found is that the boiler flow temperature is NOT being modulated by the combination of the Tado and Nefit OT to EMS adapter. The flow temperature oscillates around the heating setpoint temperature that is manually input on the front panel of the boiler. When heating is on, the flow temperature swing is tightly controlled around the setpoint. When the heating is off, the boiler still tries to maintain the same flow temperature setpoint but with a slow ponderous swing and occasional bursts of gas flame.
The attached chart shows what happened when I manually increased the setpoint from 55 to 65 deg C (marked up in yellow, "boiler heating temperature"). The average flow temp goes up by 10 deg C. The boiler did not respond to the modulated set flow temperature (in purple/magenta, "boiler set flow temperature"). Instead, the boiler seemed to respond only to my manual panel input and not to any flow temperature setpoint modulation from Tado which seems strange. I called the Worcester Bosch helpline but of course they can't assist.
I'm disappointed and hope Tado come out with an EMS2 update (for the WB Greenstar 8000). For now I've run out of ideas.
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Thanks for the update.
Are you using the EMS-ESP device from BBQKees? I have one of those installed.
You're saying that the Tado isn't sending commands to lower the flow temperature? Have you check the "three squiggles" in the app to see if they change? My understanding is that the Tado will work out a level of demand based on external weather, expected solar gains and temperature difference.
Is it possible the Tado is working correctly, but the Nefit box isn't translating the commands? Do you have any visibility into that device?
I'm using the EMS-ESP device to perform simple modulation - it checks the external temperature and sets a flow temperature based on a very loose graph. I change the "heating temperature" value as this is the one that seems to control the boiler's flow.
There is a "selected flow temperature" value, but this doesn't seem to have any real effect.
Perhaps the OT->EMS is changing the wrong value?
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even the new wireless controller (https://uk.installers-shop.tado.com/products/wireless-smart-thermostat-starter-kit-v3-eu-version) does not allow digital connection to WB boilers 2000/4000/8000 series
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How do you know that?
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Hi Tom
Because I’m just about to return mine, after a day waster yesterday with an engineer and Tado support I’m afraid to only solution for enabling modulation is the Bosch easy control
Pretty rubbish0 -
I was holding out a little bit of hope that this box would work, but so much for that.
I'm going to continue using my ESP-EMS box and I think I'll even go as far as using my own relay to control the on/off.
Thanks for sharing!
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Not compatible with modulation on WB systems
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