Added VR33 to EcoTech Plus 937 and radiators heating all the time.

Kissarmy

I have been running my EcoTech Plus 937 using eBUS from an Extension Kit for a couple of years without problem - apart from signal strength to TRVs. About to take the plunge on the Tado X discount offer but before spending nearly a grand I wanted to make sure I could still run the boiler with modulation so I ordered the VR33 module from Hartog. I have installed the module, moved the cable to the HW cylinder section from the X31 socket on the main board to the pass thru on the VR33 and plugged the VR33 supplied cable onto the vacated X31 socket. Moved the 2 wires from the eBUS socket on the main board to the OpenTherm socket on the VR33 and put a link wire in the eBUS terminals. Using the Pro app I've changed the communication protocol from eBUS to OpenTherm. Everything looks like it's working according to 'check status' in the Pro app however the one radiator in the hall that doesn't have a smart TRV is still getting hot even though nothing in the Tado app is showing as calling for heat. Any insight greatly appreciated. My discount is only valid till Monday- it took a while to get the VR33 - and I would like to know it works properly in OpenTherm mode before taking the plunge with Tado X

Rob

@Kissarmy

From my side, looking at the tado account shich shares your forum-email address, I see some weird values until Nov 17th just after midnight. Then no bus communication until Nov 18th in the afternoon, and then normal Opentherm communication since Nov 18th afternoon. So it seems you solved it.

For reference, I found this picture in my documentation of a customer who has a VR33 installed by the manufacturer (OT was/is mandatory in the Netherlands) in a Vaillant boiler. So I assume this is correct, but I'm not a VR33 expert.

policywonk

Hi. Check this list and decide on the actions needed.

1. Get in touch with Tado through the app and asked them for a specific set of instructions to make this work? If they havent responded, pester them and come back here as well.
2. If they have already provided you with full instructions and you've complied, contact support again and ask them to assist with the final reconfiguration steps. If they dont respond, come here and we can try and escalate this.
3. Is that radiator in the hallway unassigned to a room?

Unfortunately most of us dont have first hand experience with X yet.

@Rob is this your patch?

Kissarmy

Thanks for coming back to me. I think I have just managed to get it working. Reseated the cables for the VR33 which got me diagnostic D.090 eBUS controller recognised. Boiler was still running continuously. Looking in the error log had F49 which comes up as eBUS short. Removed the wire jumper on the ebus connector on the main board - which every comment I had found online said was necessary. After that the eBUS started working properly and D.023 showed heating status as blocked. I think this means that the jumper on the 24V=RT connector pretends to be a thermostat calling for heat all the time hence the boiler running all the time and once eBUS connection is working properly it overrides this jumper. As I now have a boiler that is working on opentherm I'm about to hit order on an X system. Looking forward to more than one bridge!

Kissarmy

@Rob Thankyou for getting back to me. Yes I believe I have sorted it, and having proved it works I have ordered a load of tado X components to upgrade. The picture you included is a bit confusing though. I think the boiler is probably an earlier version of the 937 as it has both X31 (ebus extension?sockets on the VR33 used - one links to the X31 on the main PCB and the other links through to the Actostor storage module at the back of the boiler. However the opentherm connector on the VR33 has a loop cable in it. It looks like the ebus input at the right of the board is being used rather than opentherm.