Worcester GC2000iW C Easy Control Key vs Smart Thermostat

HDM

Joined
22 Oct 2024
Messages
2
Reaction score
1
Country
United Kingdom
I have a Worcester GC2000iW C Combi boiler - it appears to be the model (circa 2019) that is only compatible with Worcester's own Comfort +II RF controller and the EasyControl Key. The Control Unit is pre-installed with the Key.

I wanted to know if anyone has had any success circumventing it and installing a third party smart thermostat (preferably a Nest as I purchased one before I realised!). Or am I resigned to having to get the CT200 own brand thermostat which has terrible reviews?

Thanks!
 
Sponsored Links
Wondering the same thing. I have the same model. Would have never guessed that a boiler would intentionally choose to not expose the 230V terminals. Did you have any luck with this?
 
Hi unfortunately after a LOT of back and forth with Worcester it is the case that this model isn't compatible with 3rd party controls (Nest/Hive). Unfortunately the only smart meter alternative is their own brand but the reviews of the app are awful so I've stuck with the Comfort + 2 RFI controls and have a couple of electric radiators on Alexa smart plugs I can turn on remotely for my daughter's room. Absolutely bonkers.
 
Thanks for the update. What a shame! I think I'll still give CT200 a try. All our smart home setup is on Home Assistant, and apparently it is possible to make CT200 work with Home Assistant through custom integration. So I might use that until we change this boiler.
 
Sponsored Links
Not to say that WB don't know what they're talking about (or more likely, they're trying to keep all controls and profit in-house), and I could be very wrong, but the manual does list connections for an on/off thermostat and the EMS bus, on the PCB...

Screenshot_20241124_173201_Adobe Acrobat.jpg

Screenshot_20241124_173321_Adobe Acrobat.jpg

This should mean that the boiler would respond to any WB EMS bus controller, and even Tado have an EMS implementation (although, there have been problems with separate H/W control, this should be OK with a combi).
And the On/Off connections open up a world of choice.
Although these are (extra) low voltage connections - the on/off stat would have to have 'voltage free', or 'dry contact' relay terminals.

The caveats though, there will be some loss of efficiency using controls other than WB own EMS controllers and the PCB terminals are mounted behind the boilers (room sealing) front panel - making them effectively inaccessible to all but an RGI.
 
Last edited:
Not to say that WB don't know what they're talking about (or more likely, they're trying to keep all controls and profit in-house), and I could be very wrong, but the manual does list connections for an on/off thermostat and the EMS bus, on the PCB...
This should mean that the boiler would respond to any WB EMS bus controller, and even Tado have an EMS implementation (although, there have been problems with separate H/W control, this should be OK with a combi).
And the On/Off connections open up a world of choice.
Although these are (extra) low voltage connections - the on/off stat would have to have 'voltage free', or 'dry contact' relay terminals.

The caveats though, there will be some loss of efficiency using controls other than WB own EMS controllers and the PCB terminals are mounted behind the boilers (room sealing) front panel - making them effectively inaccessible to all but an RGI.

Thanks very much for this! I looked into it a bit last night, and although I’m in way over my head, from what I understand, it should be possible to connect something like this EMS Gateway to the EMS bus.

This device seems like a handy tool for interfacing with the boiler, and it’s compatible with Home Assistant (as demonstrated by a gentleman here). I also have temperature sensors and smart TRVs in nearly every room of the house, so it should be possible to create automations in Home Assistant to control the boiler and adjust the TRVs based on the temperature requirements of individual rooms.

I’m fine with the efficiency loss from not using the modulating functionality, as long as this setup works reliably. However, I suspect that most (if not all) of the data from this boiler would be read-only and not adjustable. I also wonder if this might fall into a regulatory grey area :unsure:

Has anyone here tried a similar setup? It might be worth a try.
 
, from what I understand, it should be possible to connect something like this EMS Gateway to the EMS bus
Interesting, I've recently been investigating the Vaillant eBUS protocol and open source projects around that. I hadn't realised there were also projects based on EMS.
I’m fine with the efficiency loss from not using the modulating functionality, as long as this setup works reliably.
The efficiency gains through direct modulation control, should theoretically be there with EMS control, but to get that set up properly is beyond me!
Even some smart on/off stats have load compensation, that enables efficiencies to be gained that aren't far off modulating stats (at the expense of more boiler cycling).
I also wonder if this might fall into a regulatory grey area :unsure:
The biggest regulatory problem, is getting to the on/off, or EMS terminals to begin with! :)
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top