Hello. Not sure if other people see the same who use open therm connection. The other day I had two zones that had fallen 2 degrees below the set point, and the other 7 zones were at the correct...
Type: Posts; User: Norfolkboy
Hello. Not sure if other people see the same who use open therm connection. The other day I had two zones that had fallen 2 degrees below the set point, and the other 7 zones were at the correct...
Hi, after some help.
One of my HR92s has gone wrong. On the screen it's showing frost and d4.8 and on the main Evo control panel the temp fluctuates from a minus number to 99c! I have tried...
Thaks for the reply. Mmmm im not sure if i have had HW on without the CH on, probably in the Summer i will have the answer! The switch wires have been disconnected FYI
To add to my comment above- I have also discovered that the Boiler cycle settings and HW Pump overrun time in the Evocontroller doesn’t work with Opentherm and Viessman.
Not major issues just more...
Viessman 100w Openvent boiler- Running Opentherm. No extra demand box required to get max flow temp for HW. Flow temp for CH modulates up and down well, however everytime there is a change in flow...
Viessmans response was Opentherm is like putting a BWM gearbox in a Mercedes! Very helpfull. its a niggle which i can live with, but agree with Hengus that no one supports Opentherm fully and both...
Yep, I know its a bit infuriating! Doesn’t make the system very smooth
Hi, i have posted this question in a different thread i had started, but have a few more details about the ongoing issue.
Whenever there is a change in demand from a zone(s) and therefor the...
Not quite as OT is priority 2 and demand box is 3, and as OT was calling for 78c heat as well then that would be still be priority, that's why the tap symbol did not appear on mine when dew was on
I dont get the tap symbol, the rad one stays on but the boiler temp increases once Evo calls for hot water. it works if no heating is on or zones are calling for heat, it overrules the heating flow...
I'm come to the conclusion that OT is not 100% reliable in the way is talks to the boiler, doesn't seem that the "common" language used is translated correctly all the time- flow temp is good on mine...
Thmaks for you update, yes we have the same system, but weirdly mine didn't required the hot water demand box, OT seems to up the flow temp to 78c when hw is on. Must be a firmware difference?
Hi,
Thought i would give an update after 10 days. the low flow temps have gone away so looks like the learning mode was causing these issues, Optiumstart is still learning with a few rooms a good...
Good idea, where did you get your HGI80 from out of interest. This seems an easier way to get the info, than trying to get the data from the web via Honeywell api
Hi,
As the title says, i have read and read and tried but cant understand what i need to download, run etc! im usually very good at tech, but my computer code is a different story
As a fellow viessman owner, I have a 26kw version, 3 floors 14 rads in the 60 year old house. I also thought I needed the demand box so bought it, but then tried it without connecting it up and the...
I don't have a touchscreen, can you adjust the boiler setup on that? I am unable adjust anything on mine, which may help with the short cycling I'm seeing sometimes
Thanks for this once mine gets going it does s a good job, just seems a little strange getting up to desired temp. Did you need the optional hot water demand box from viessman, to get max flow temp...
Thaks for that, what is the lowest temp you have seen it modulate at, my system sounds indentical to yours but im see it modulate at 28-33C which seems too low, also viessman just told me -"I would...
Just asked Viessman if they have had any problems with Opentherm, and the response:
I would not use Opentherm myself, it's a bit like fitting a BMW automatic gearbox to a Mercedes-Benz.
Looks...
From Viessman :
The Europe market boilers do not have the facility to change the overrun time parameters.
Pump overrun on all Vitodens 100-W boilers is temperature controlled, and it is...
I agree, something isnt right with the Opentherm bridge, i witness this morning when zone came on, the boiler firing on/off 3 times in 1 minutes, and one of these times shutting the boiler right down...
Hi, are you running overtherm as well?
Once agian DBmandrake you have answered my question helfully! Thank you.
An odd question but is the best way to get a room to heat up quickly to set the temp much higher than desired, and thus get...
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