It will modulate to max when there is a hot water demand. How long has it been installed with OT?
If you need help please refer to this doc http://www.honeywelluk.com/documents...rt_process.pdf
Think it is all connected right. I've powered down the original BDR91 heating relay, and for good measure disconnected the switched live inside the boiler. The Vaillant diagnostics report the module as detected, and its picking up a target temperature as coming from the remote controller. In terms of comfort in the house everything seems pretty much as it was before, so the main thing is that we still have heating!
Update: boiler target currently 51C. House is warm and starting to shutdown for the night, so it's easing back. So it definitely looks like it's working as it should!
Last edited by StuartG; 10th March 2016 at 11:13 PM.
It will modulate to max when there is a hot water demand. How long has it been installed with OT?
If you need help please refer to this doc http://www.honeywelluk.com/documents...rt_process.pdf
I work for Resideo, posts are personal and my own views.
Think we posted at the same time. Just went to see what it is up to, and it's now getting a target of 51C from evohome, so it is working fine. Thanks for the link. Will check it out!
It's good to know that the VR33 works with UK supplied boilers because there's other places on the Internet which suggest that because of different firmware on this side of the channel it won't work properly.
That always seemed like a silly argument. Nice to have suspicions confirmed.
I work for Resideo, posts are personal and my own views.
It might be worth starting a list of UK boilers know to work well with Evohome+OpenTherm.
Even if it's only an 'unofficial' lists because Honeywell can't be seen to favour manufacturers, or recommend buying unsupported/imported bits (HGI80 - cough!)
I remember someone posted a while back that with one particular boiler the heating works fine but the hot water doesn't.
P.
I'm puzzled why boiler manufacturer's would want to limit availability of the technologies. I chose Evohome because I felt it was the right thing to do to try and improve the energy efficiency of my house. At the moment I think these sorts of technologies are probably taken up more by people with the "early adopter" mentality who are happy to try things out, find work arounds to problems, and be prepared to be a little bit patient if it doesn't always work "out of the box" first time. Surely that's good for manufacturers in terms of promoting the tech, and gathering feedback from an informed and motivated user base?
Anyhow, I'll try to remember to post every now and then if I get any major insights to how the system is performing. I have trends going back since it was installed in terms of how well the system is maintaining temperatures, and over time I might be able to infer something about efficiency from gas use. For now I'm just happy that the system is working, so it must be "optimised" and any measurable savings would simply confirm what the optimisation has achieved.
In all cases evohome will work with all boilers using the standard BDR91 wireless relay
For modulation of the flow temperature using openTherm bridge basically anything with OpenTherm interface including models from:
ATAG
Intergas
Ideal current range
Ferroil
Remeha
Vokera
Viessmann 050 and 100 series
Others that can be made OpenTherm with adapters include
Worcester Bosch
Valillant
I work for Resideo, posts are personal and my own views.
But I seem to recall it was Viessmann that someone had a problem with. Which is why I thought a list of 'known good' boilers might be useful, based on actual experience.
P.