Opentherm mode on Vokera easi heat 25

[Tomat35]

I have a Vokera easi heat 25c boiler it is currently using the built in mechanical clock timer and a wired thermostat on the wall next to it to control it.

I am getting the vokera 7 day programmable wireless (Vokera 20059643 RF Thermostat although it has arrived and it’s branded Alpha). And the additional controls interface plug in bit which the web says I need to make it work with this boiler.

I want it to be Boiler Plus rated and it seems like this change will do it by being Opentherm controlled ( I don’t fully understand either term but I hope I don’t need to).

When this is plugged into the boiler will this then be compliant?
What does the reference to it being in OpenTherm mode? Is that an adjustment I need to make?
Thanks for your help.

 

[CBW]

@vulcancontinental will be your man for this should get a nice explanation from him. Tagged in so he will see it.

This my understanding: Boiler plus is the latest in helping with heating and boiler efficiencies. Opentherm is a data language that “talks“ to the boiler and is only dependent (usually) on how it’s wired into the boiler, not a mode to select. Yes this should then make it boiler plus compliant.

 

[Madrab]

As far as I am aware, the controls need to have load and weather compensation (LC/WC) included and smart to be Plus compliant. I believe the Vokera would need the BeSmart controls and the outdoor sensor to include weather compensation. I don't think the programmable stat you have highlighted is WC enabled. Though I am sure VC will be able to clarify.

Other requirements are passive flue heat recovery, a boiler @ 92% efficiency, etc. These are not retrofit requirements, rather only relative on new installs.

Not relative to us up here but I do remember some of the blurb when the specs came out.

 

[CBW]

As far as I am aware, the controls need to have load and weather compensation (LC/WC) included and smart to be Plus compliant.

Only 1 by the looks of it mate:

 

[Tomat35]

Only 1 by the looks of it mate:

I have seen another flow chart that does seem to suggest only one of the options is needed too, thankfully.

 

[Tomat35]

I think you’re right by saying it’s not a special mode or anything.
Why put the asterisk there? I think maybe it’s just a bit more information to clarify how it meets the requirements.

 

[vulcancontinental]

Timed and temperature control on a combi plus 1 energy saving measure for Boiler Plus.
WC.
OT
PFHR
Smart Stat

To convert the stat is simple but you'll need the controls interface.

 

[Madrab]

Only 1 by the looks of it mate:

As suggested, we don't have it up here so it's not something I keep track off.

Good to hear it's not all of them then as that could get expensive, though that being said I guess implementing them all would make the system as efficient as it could be.

 

[Tomat35]

Thank you very much

Open Therm and this controller satisfy the load compensation criteria then.

Thank you for signposting the video, that’s exactly what I needed.
Disappointed I didn’t find/skipped over it in my own Vokera and google rabbit hole.

 

[hingus2000]

Timed and temperature control on a combi plus 1 energy saving measure for Boiler Plus.
WC.
OT
PFHR
Smart Stat

To convert the stat is simple but you'll need the controls interface.

Hi Vulcan

I bookmarked this post ahead of moving into a new house with a Vokera Vision 30C, with the intention of installing a wired Tado to modulate it.

I've now moved in and the video has been removed!

Acting from logic/memory, I installed the Vokera Controls Interface on CN6 and took the thermostat wires out of CN5 and placed them in the left-hand two blocks of CN6. However, although the boiler would still give hot water, it wasn't communicating with the Tado.

I then bridged CN5, and the boiler is communicating with Tado (according to the Tado Pro app), but there is no heat or hot water when called. The boiler boots up, but then shuts itself down (- - symbol on screen).

Very grateful if anyone could provide any suggestions (or if the video could be re-uploaded).

Thanks very much.

 

[vulcancontinental]

Afraid the videos are gone, they asked me to remove them.

I know little of Tado except that some time ago they removed bus control from the system in the UK and it became on/off only. I understand Tado is still OpenTherm in Europe, it depends where you buy it from.

For the time being you could use Tado On/Off in connections CN5 until you know whether the version you have does work OT.


I never tested Tado with our boilers OT but the important thing is the control must be capable of setting DHW temperature as when connected OT the controls on the boiler fascia are disabled.

 

[hingus2000]

Afraid the videos are gone, they asked me to remove them.

I know little of Tado except that some time ago they removed bus control from the system in the UK and it became on/off only. I understand Tado is still OpenTherm in Europe, it depends where you buy it from.

For the time being you could use Tado On/Off in connections CN5 until you know whether the version you have does work OT.


I never tested Tado with our boilers OT but the important thing is the control must be capable of setting DHW temperature as when connected OT the controls on the boiler fascia are disabled.

Appreciate the quick response.

Tado removed bus control from its wireless thermostats, but it remains on its wired stats. The wired Tado thermostat I have definitely supports OT and is wired on the digital terminals at the thermostat using the previous NO and COM wires from the boiler which fed the old mechanical stat.

The issue might be that the NO and COM wires did not feed straight into CN5, but rather a separate block (M2) off the PCB. Two blue wires then came off this block, one into CN1 and then into CN5 and one directly into CN5 (and CN5 has now been replaced by CN6). I guess this may be something to do with the boiler fascia controls?

I was going to try wiring the wires from the thermostat into CN6, bypassing CN1, unless you have any other suggestions.

Thanks again

 

[vulcancontinental]

Not following completely but the two OT connections from Tado go into the OT connections on the controls interface, that's it, you need do nothing else.

The clock will still show alarms etc. but not have any influence on the boiler. CN 5 control is ignored once OT is connected.