Evohome + Opentherm v Evohome + Boiler Outside Weather Compensation

[roydonaldson]

the notes you describe are available as part of the online training course? they are certainly provided on the face to face installer training course. please bear in mind that evohome is fundamentally a product for professional trade installers.

evohome can be applied in a variety of ways and as long as you follow guided configuration (and crucially answer the questions carefully) and refer to section 3 of the manual to bind the devices all should become clear.

hope this helps explain why the product is the way it is.

I've had a try at putting something together. I'm in the office so don't have a controller to hand to pull more screen shots from. But, do app notes such as:

https://cisco.box.com/s/lk31whtaleis...9fap3l2mx7v55e

exist then ?

[bruce_miranda]

I did my best to try to explain this at post #53

Now when I read it again, you are right you did! Infact both HW and CH zone valves are configured in the Hot Water configuration set-up in evohome. That's the bit that threw me a bit.

I also made some progress as to why both me and my trained installer couldn't work out how to install the HW Kit on my Vaillant Unistor. As it happens, I have one of the earlier versions of the Vaillant Unistor that doesn't have a free dry pocket for the NTC sensor, as shown in Vaillant's own instruction manuals. Instead I need to remove the cylinder controls completely and that frees up a dry pocket that I should be able to use for the Honeywell HW kit. Guess where I found that out, in the Vaillant VR65 manual. I went there only because I wondered how Vaillant themselves used an NTC probe as part of their boiler and cylinder eBUS configuration.

Now the only open question is whether my UK Vaillant boiler will recognise the Dutch Vaillant Opentherm module VR33. That's on it's way to me now. So only time will tell.

Can either Stuart or top brake tell me how they confirmed if Opentherm was working between the boiler and the OT Bridge?

[top brake]

VR33 installed.jpg

Now the only open question is whether my UK Vaillant boiler will recognise the Dutch Vaillant Opentherm module VR33. That's on it's way to me now. So only time will tell.

Can either Stuart or top brake tell me how they confirmed if Opentherm was working between the boiler and the OT Bridge?

the flow temperature when in heating mode will be lower (leave a week and you should see 54 degC, leave a few more weeks and you should see 46 degC) and the flame icon smaller :-)

the instructions supplied will literally be double dutch but the VR33 is pretty easy to install, plug and play. I have a few pics to help you

Fit board into slot on left
Fit patch cable as per instructions supplied

Ensure 24v RT is linked
Ensure Burner off is linked
Ensure Ebus is NOT linked

Wire R8810A1018 to OT terminals on VR33


if you have access to the installer settings I understand that you can check there

[bruce_miranda]

Please post as many pictures as you can. I too will document my Opentherm installation for others.

[jdp80]

Please post as many pictures as you can. I too will document my Opentherm installation for others.

Keen to see how this works out!

[bruce_miranda]

VR33 installed.jpg
Ensure 24v RT is linked
Ensure Burner off is linked
Ensure Ebus is NOT linked

Wire R8810A1018 to OT terminals on VR33

Again no wonder why I didn't understand this post.

I have a Vaillant Ecotec Plus 438 open vented boiler. So my connections are slightly different. I don't have 24V RT, Burner Off and EBus. As shown in the diagram below.

22090566.jpg

Instead I have the following.

ecotecboiler.jpg

I'll try and see what the 7, 8 and 9 correspond to in terms of 24V RT and Burner Off. (Except I'll be ignoring the warning message elsewhere in the manual! - see image)

rbhzqe.jpg

I guess the OT terminals on the VR33 are big terminal block T10 which is connected by the Red jumper wire when you buy the VR33.

[top brake]

Not sure that the VR33 will work for your boiler

[bruce_miranda]

Not sure that the VR33 will work for your boiler

Ouch! Now you tell me. Is the VR33 only supported on certain Vaillant boilers? The VR33 said it was compatible with Vaillant ecoTech Plus, which mine is. So I took the plunge.

[paulockenden]

See this translated Dutch site. I think it gives the details you need:

https://translate.google.co.uk/trans...-text=&act=url

[bruce_miranda]

Most of the installations seem to be on Combi or System boilers. My boiler is a standard open vented and doesn't have the 24V RT and Burner Off jumpers. So it will be interesting to see if I can even install the VR33 in my Vaillant. I'll let people know how I get on.