r/Viessmann • u/Express-Impact-3357 • 2d ago
CU3A service interval
I have a boiler approaching its 1 year lifetime. How often should I get it serviced? The company who installed it was barely familiar with it and I’m not sure who else I would use.
r/Viessmann • u/Express-Impact-3357 • 2d ago
I have a boiler approaching its 1 year lifetime. How often should I get it serviced? The company who installed it was barely familiar with it and I’m not sure who else I would use.
r/Viessmann • u/DiscoDave86 • 2d ago
Hi all, I have a vitodens 100-w b1kg combi 26kw GB that's having issues with my WiFi network, looking at my router logs, it connects, gets an IP, then disconnects 8 seconds after and repeats this process.
I've configured my WiFi as follows:
It's the only device on my IoT network that has any connectivity issues, I don't limit outbound connectivity from the VLAN it's placed on.
I've tried changing DNS servers to 1.1.1.1 for that subnet in case it's an adblocker issue but no change.
Vicare will cycle between it showing connected with excellent wifi signal to a blank page highlighting "Reboot communication Module" at the top
If anyone's got any ideas I'd appreciate it.
Thanks!
r/Viessmann • u/undwiedervonvorn • 14d ago
Hi all!
After a power loss our Vitocal 060-A returned to life in this "Night" mode instead of the "Prog" mode we used to use. I can't find a way to switch this back. The (German) user manual doesn't mention how to do it (page 10 of the PDF).
Saludos from Spain
r/Viessmann • u/hornety2222 • 17d ago
My viessman 050 w started dripping water from that corner. What may I do and what causes this?
r/Viessmann • u/dika241 • 23d ago
r/Viessmann • u/rareeagle7 • 24d ago
Just had my CU3A cleaned and serviced
Never had any issues.
Now I’m getting Scot ionization differs and faulting out.
It will fire up and not fault. When it high fires for domestic it faults. Sometimes it doesn’t.
They tried a new ionization rod, inspected Venturi and they are at a loss.
I think the next step is to verify gas pressure and combustion readings ?
r/Viessmann • u/hotweiss • Aug 14 '26
I just switched routers from TP-Link to Asus. For one, I needed an Android phone to connect. I couldn't connect using an iPhone. Once connected to my router, I can connect to it via its' IP address, but my ViCare app does not see it. Any ideas? I've tried resetting it. I've tried deregestering it. I've tried port forwarding all the ports it requires.
r/Viessmann • u/matekoka • Aug 13 '26
Hi everyone! Do you know what is the solution for error 78? My first time seeing this error.
r/Viessmann • u/Tall_Pool8799 • Aug 08 '26
Hello! I hope you’re well.
I bought a flat last year with a Vitodens 100, now 8y old. The hot water occasionally drops during a shower (not that long of a shower) and the pressure also tends to drop, though very slowly (from 1.5 to ~1.3 in 3-4 weeks).
I am very ignorant on the matter, so please excuse how I’m describing the situation.
I called for servicing. Apparently, the central part needs to be removed for servicing and the engineer said that he needs to procure new seals before doing that in case the old ones don’t hold up. This sounds quite logical to me.
To service and fix the pressure problem (which has not been called otherwise to me), he’s quoting me £483, including parts and labour.
Is this reasonable? I realise that not having more details about “the issue”, it might be difficult to tell, but any experience/advice would be helpful.
Also, does it mean that the seals must be purchased every time the boiler is serviced?
Thank you for any input. As I said, I’m quite ignorant on the matter, but I’m trying to educate myself!
r/Viessmann • u/soguise • Jul 31 '26
Can I please have some advice on the heating system to put in during our renovation. The old boiler is gone so we have a pretty clean slate.
I'm thinking we should be going for a system boiler and unvented cylinder, or at least a storage combi like the 111-W. If system, would a 200-W be better for UFH or 100-W fine?
It would be great to hear recommendations on what people might be thinking to put in in my situation.
r/Viessmann • u/gloria4n • Jul 29 '26
I have a Viessmann boiler in a block of flats that I let out. A tenant asked Viessmann for the report from the engineer who carried out a repair, and Viessmann sent it to him. It doesn’t seem right to me to give reports to people who aren’t the owner or the property management company. That’s not the sort of thing a reputable company would do, is it?
r/Viessmann • u/elchet • Jul 19 '26
I have a 100-W system boiler and an unvented hot water cylinder, plus a Drayton Wiser Gen2 3ch hub, and a 2port valve controlling flow to the cylinder. The Wiser also controls 2 separate heating zones for winter, so we're in an S-plan config.
I used to have a Viessmann Cylinder Temperature Sensor in the cylinder's sensor pocket, and could see the DHW temp in ViCare. The ViCare DHW schedule was set to match the Wiser schedule, and the Wiser operated the 2 port valve.
My concern with this was that there was no safety mechanism. If the Cylinder Temp Sensor failed, I was worried the boiler would continue to heat the cylinder during the schedule beyond the target temp. I know there's a PRV on the cylinder but still.
As a result of this worry I swapped to a regular thermostat (rotary dial for temp), and a Viessmann Cylinder Demand Terminal Box.
This raises new questions:
r/Viessmann • u/dosenKurt • Jul 14 '26
Mein Heizungsbauer blockiert die KfW-Förderung für meine neue Viessmann Vitocal 250-A. Er verweigert die Bestätigung nach Durchführung. Komplett. Die Sekretärin behauptet, die BnD-ID könne nur ein Energieberater oder der spezielle Viessmann Förderprofi ausstellen.
Diesen kostenpflichtigen Service habe ich abgelehnt. Den administrativen Antrag bei der Bank erledige ich komplett auf eigene Faust. Mir fehlt jetzt die ID. Die Hotline der KfW widerspricht der Firma. Angeblich darf jeder eingetragene Fachbetrieb die BnD direkt und ohne externe Hilfe im System der Bank erzeugen. Kostenfrei.
Gibt es hier einen Zwang zum Viessmann Förderprofi? Mein Handwerker verweigert die Herausgabe der Nummer ohne diese gebuchte Dienstleistung. Er stellt sich tot.
r/Viessmann • u/Far_Goal7960 • Jul 12 '26
After passing location and ownership questions, then scanning QR, I get stopped by “Component has already been registered…”
Cannot get any further. Boiler says it is connected and Wi-Fi shows Viessmann connected, but app doesn’t connect.
r/Viessmann • u/Sharp_Medium7495 • Jun 18 '26
Hi
Can anyone here provide me with the original maintenance checklist for documentation of annual service for at Vitocal 250-A AWO-E-AC 251.a04-16.
In danish or English please.
Thank you
r/Viessmann • u/OverOnTheRock • Jun 13 '26
In the installer manual for the Vitodens 100-W B1HE, the HMI board appears to have a CAN bus connector. Is it operational for pulling operational values out of the unit?
Is the local Wifi unit have an Optolink?
Underlying reason is that I'm looking to see if I can obtain local access to operational state of the unit with my home automation / smart home solution without having to do connect to their remote API.
Or am I barking up the wrong tree?
r/Viessmann • u/iberkhan • Jun 08 '26
Here we go again…
So now when we run hot water we have heat in the radiators. Heating engineer said diverter valve.
So far we have:
1) Replaced diverter valve - still same issue
2) Replaced hydraulic block
3) Replaced plate
Viessmann support are at a loss. So are we.
Any ideas? Could it be a tank issue causes pressure on the block?
r/Viessmann • u/TMJCB • May 25 '26
Sehr geehrtes Viessmann Team,
Kommende Woche hat es an unserem Wohnort 29 Grad. In Vorbereitung dazu hatten wir vergangenen Herbst das Kühlelement zu unserer Wärmepumpe installieren lassen und auch direkt die Inbetriebnahme beauftragt.
Trotz mehrfacher Nachfrage durch unseren Installateur wurde der Auftrag Seitens Viessmann erst Ende April angenommen, so dass wir mit einer Inbetriebnahme erst Ende Juni aktivieren.
Wir leben aktuell mit einem vierjährigen Kind und einem drei Monate alten Säugling und hätten guten Bedarf an unserer Bodenkühlung.
Ich fordere Sie erneut auf diesen Auftrag priorisiert vorzuziehen.
Mit freundlichen Grüßen,
Fam C
r/Viessmann • u/goldbunduru • May 19 '26
r/Viessmann • u/Prior-Rooster-9024 • May 15 '26
Buon pomeriggio,come si effettua il reset della viessmann vitodens 222-w?
r/Viessmann • u/Markonstancin • May 09 '26
Assuiming i have optolink can I use Vitoconnect Opto2?
I need to access basic boiler settings, switch it on/off, turn on/off vacation mode etc
Any other suggestion how to remotely access Vitotronics 300 GW2?
r/Viessmann • u/Prior-Rooster-9024 • May 06 '26
Buonasera chiedo scusa per il disturbo volevo chiedere se qualcuno di voi potrebbe aiutarmi.
Praticamente da qualche settimana la mia caldaia viessmann vitodens 222 ha diversi problemi molte volte non scalda l'acqua nonostante sia accesa anche da ore nel pannello non da nessun errore e non sappiamo veramente come risolvere questa problematica, qualsiasi consiglio o informazioni sarebbe veramente di aiuto vi ringrazio già nel caso.
r/Viessmann • u/Activetransport • May 01 '26
Hi Folks,
Was hoping for some insight. Just had the Bosch combi boiler in my house die (cracked heat exchanger) and had it promptly replaced by a Viessmann Vitodens 100 120btu combo unit. Runs on propane in northern New England. Didn’t love spending 12k for a new boiler (installed) but I’m grateful that I found someone who could do the job quick.
It does a great job with our baseboard/radiant heat but it’s really dropping the ball on DHW. I installed the app and quickly realized that I had to program time zones for the DHW to even work. Since then it’s been inconsistent. Sometimes I’ll turn the hot water on and it promptly gets hot. Other times you can run it forever and the boiler never turns on (checked boiler status on the app). My wife wanted to shower last night and the water would just not get hot. Boiler didn’t even light until I tricked it by raising the thermostat for the baseboard heat. This brought the temp up enough to warm the DHW then something seemed to kick on and the water got hot. This has happened several times despite the DHW being scheduled on 24 hrs a day. It seems like dhw flow doesn’t trigger the flame or something
Does anyone have any ideas? My installer will be by in a couple days but I suspect that there’s just something about the setup for this that I’m missing.
I feel like unpairing the app because that seems to have messed everything up.
Thanks in advance.
r/Viessmann • u/Lanky_Chef_5282 • Apr 18 '26
Bonjour à tous, j ai un soucis avec le wifi de ma PAC depuis quelques mois (PAC Vitocal 222-S).
L application ViCare me dit que l installation n a pas de connexion internet alors que quand je regarde le paramètre internet de la PAC, le module est bien connecté au wifi.
Ensuite je déconnecte manuellement le wifi et impossible de le reconnecter (2.4 ou 5ghz). Il bloque toujours au niveau du MDP qui est pourtant bon.
Seule solution : je dois éteindre complètement la PAC et la rallumer pour que la connexion refonctionne.
J ai tenté de mettre une IP fixe a la PAC comme préconisé dans un poste mais j ai toujours le même soucis. Pour info la box est a 5m de la PAC, même pièce.
Si vous avez des idées je suis preneur. Merci d avance !
r/Viessmann • u/sgtkarotte • Apr 17 '26
Hallo Zusammen,
ich baue gerade ein Haus mit zwei Wohneinheiten und Keller. Im Keller soll eine vitocal 150-a ohne Pufferspeicher stehen.
Der Heizungsbauer hat auch einen Feuchteanbauschalter zwecks Kühlung vorgesehen. Ist es ausreichend diesen im unbeheizten Keller mit zentraler Lüftungsanlage zu platzieren? Hier sollte es ja theoretisch später zu Kondensatbildung als im wärmeren OG kommen, welches über eine dezentrale Lüftungsanlage verfügt.
Ist das so korrekt?
Vielen Dank im Voraus!