viessmann vitodens 050-w + OpenTherm + Preheat - now fixed
hi,
recently i had this boiler installed originally on relay on/off.
after watching some youtube videos and learning about opentherm, i asked the installing company to change the wiring over to opentherm.
once this was done, the eco mode was no longer available. so the pre-heat functionality was always on, very annoying and obviously using extra gas which i didn't want it to.
i couldn't work out who would be able to fix this (tado or viessmann).
i raised a support case with viessman, had an engineer out today who remoted onto the boiler via his laptop to override the hot water control from tado system.
he changed the settings on the boiler so now i have eco mode back, tado opentherm can no longer control my hot water but it is still controlling the opentherm for the heating.
happy days
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he did mention that tado won't be able to control the HW going forward so fingers crossed
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how are you finding the combination? I have the UK wireless receiver which is relay on/off only - but they’ve just started selling the modulating version again in the UK.
I’m not sure whether to update to the opentherm version, or keep relay and let the boiler handle weather compensation. To my understanding
- boiler weather comp - will set flow temperature based on outside temperature - needs an external sensor
- Tado controls - will set flow temperature based on the load being called for - eg how much heat/difference between room current temp and desired temp but doesn’t take into account weather so may call for high boiler heat even in spring when not necessary
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Tado does have a form of weather compensation- it uses online weather data, which is less accurate than a sensor but should reduce output on sunny days.1
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I used this to set the HW control via Tado
I'm still struggling to get the Viessmann to report if its on ECO or not though - I'm assuming not as its not instantly hot. But maybe I should get them to remote in, they seem to have access fine as I've hooked the boiler up to the WiFi.
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@Floob once in opentherm, the only way to get it in eco mode (pre heat off), is to get a viessmann engineer to come to override the DHW.
enabling HW control via Tado, the pre-heat mode is set to on still. what i noticed to help, was to set the temp to 30C (lowest it can be set) at night time, and this stops firing the boiler as often.
i would email viessmann support to arrange an engineer to get this fixed as they done it for me
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@Ervcrt100 Thanks, I'll contact Viessmann and see if they can do that remotely.
If I were on pre-heat mode would the water be instantly hot?
Are you saying you are controlling the hot water temp via Tado, but that it is also on Eco mode?
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@Floob i'll doubt they'll be able to do it remotely, an engineer came out for mine and connected to the boilers AP.
it should be hot but i didn't want that as its using extra gas etc to keep the water warm.
before the engineer come out, i did have the HW tile enabled in tado, but post his fix, i've removed the HW control setting in tado.
so now, i can control the HW via the boilers digital display and via the ViCare app, i can also do this for Eco mode aswell.
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@Ervcrt100 I mean when you had it on pre-heat was it immediately hot?
Mine isnt instantly hot which is why I was thinking it may be on Eco mode?
Is this icon now showing on your boiler display?
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For what its worth, on a day when I dont use the gas, the meters register 1.3kWh of gas use.
I wonder if thats indicative of pre-heat. I dont hear the boiler kicking in during the day though (only when water used or heat called for), so I'm not sure, I'll see what Viessmann come back with.
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no wasn't instant, would take bout 10 secs i would say.
yes i have that icon available now on the boiler and can turn on and off.
that is interesting, mine was kicking in every hour approx.
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So Viessmann replied and said:
"The Boiler indicates that the DHW is currently in Standard operation, Had it been in Eco then pre-heat would be off however it looks likely that pre-heat is still active."
So all signs point to the boiler not being on Eco mode. That said with 1.3kWh being used when I'm not in (so in my mind I'm assigning that to pre-heat), I'm possibly not going to look to change that setting.
Viessmann then replied when I asked them about the usage with:
"Once Opentherm is connected the Boiler panel no longer has any functional control so it would not be possible to change yourself manually. We do not have any costs on Gas usage when operating under Pre-Heat I'm afraid, the assumption has always been that it can only be a small amount of gas as it is not heating up the property, just the internal pipework and plate heat exchanger in the boiler itself, which, over a 24 hour period may not amount to more than 'Minutes' in real terms rather than hours."
I'm not sure if pre-heat would "fire" the boiler up, if it does then I've not heard it, but I think I'll keep the status-quo for the moment and manage the water temp on Tado and leave it on "standard".
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Pre-heat will definitely fire up the boiler, that’s the only way to keep the water at temperature. Sounds like it isn’t turned on on your boiler.0
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Ah - thanks. Mine looks like this, if I try to tweak it, it just jumps back to the Tado set temp after a few seconds.
I'm a bit unsure of how much it uses, but no-one was in on the 1st and 2nd October, and the EDF app shows the following:
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Thank you so much for posting this information. I emailed viessman and they initially told me that because I was using opentherm the boiler would function as a slave unit and eco and temperature controls would be disabled. However I sent them a link to this forum post and my serial number and they changed my settings remotely. I have full control over the hot water on the boiler and the vicare app and eco mode is enabled and working.1
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hi, i have a Viessmann b1kc, how should I check if this is an issue with mine as well,
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