Viessmann Trouble Slow Heat Up

[Julian Such]

Hello Everyone,
Viessmann Vitodens 200w fitted with weather comp. I have a Tado V1 which says that the room is too cold and is demanding heat. However the boiler is taking two hours to heat the room and running at 29% output. Something does not feel correct, any thoughts?

Julian

 

[doitmyself]

Heating curve not correct?

Does the Tado communicate with the boiler so the heating curve is adjusted when the required room temperature is changed? If it doesn't, the heating curve will only be correct for one specific room temperature.

 

[Gasmk1]

i would check with viessmann as tado might not work properly with them the viessmann's 200's own weather comp is far superior to tado controls

 

[townfanjon]

Is this a new installation ?

 

[999]

The 200 set up correctly with weather comp shouldnt need something like a Tado. How long has the Tado been fitted?

 

[Julian Such]

Is this a new installation ?

Yes, last week completed Friday. My installer is Viessmann Registered but I am interested in solving this. It feels like a heating curve although I am on 2.0 at present.

 

[Julian Such]

The 200 set up correctly with weather comp shouldnt need something like a Tado. How long has the Tado been fitted?

Tado has been fitted for 5 years, Viessman last week. We really like the Geofencing of the Tado. I feel like I have taken two steps back.

 

[999]

If you want to use Tado to its full advantage then you would have to disable the weather comp on the viessmann.

 

[Julian Such]

Hmmm, so the weather comp is better than Tado? and you say I should not turn off the system. if the boiler is on at 2.00am, is that not a waste? I saw that I can change individual days for temp programming. What about HW control with the Viessmann?

 

[999]

Dont set it to be on 24 hours a day that is a bit excessive. Try 6am - 10pm if using the weather comp on its own.
How is the hotwater controllled ?
I take it you are using stored hotwater ?

 

[Ric2013]

Hmm. Could it be that the Viessmann is firing at 29% output because there aren't many radiators in the system? The 200 is a large boiler.

 

[999]

It will be firing at 29% based on the outside temperture, the heating curve and the set room temperture.

edited: thought i was answering the OP lol

 

[Julian Such]

Lots of conversations. 14 Rads, Wirral Coastal location, Victorian Semi. We have a Megaflow type system with HW Controlled by the tado. Does the Viessman have a HW Control? and secondly , and I know it sounds a little witchcraft but how does the Viessman Know it is 19 degrees?

 

[999]

On the front of the viessmann 200 should be a control panel is it the latest touchscreen one ? you should be able to set the hotwater in there to come on at a particular time.

Your heating system is preset at the factory and is
therefore ready for operation:
Central heating
■
Between
06:00 and 22:00 h
, the rooms are heated
to 20 °C
"Set room temperature"
(standard room
temperature).
■
Between
22:00 and 06:00 h
, the rooms are heated
to 3 °C
"Reduced room temperature"
(reduced
room temperature, frost protection).
DHW heating
■
Between
05:30 and 22:00 h
, the DHW is heated to
50 °C
"Set DHW temperature"
. The DHW circula-
tion pump, if installed, is switched on.
■
Between
22:00 and 05:30 h
, the DHW cylinder is not
reheated. The DHW circulation pump, if installed, is
switched off.

 

[townfanjon]

Yes, last week completed Friday. My installer is Viessmann Registered but I am interested in solving this. It feels like a heating curve although I am on 2.0 at present.

Miles too high pal , should be 1 . 5ish .

 

[doitmyself]

Miles too high pal , should be 1 . 5ish .

How can you say that? The heating curve will depend on the heat loss from the property which in the OP's case is a Victorian semi.

 

[townfanjon]

How can you say that? The heating curve will depend on the heat loss from the property which in the OP's case is a Victorian semi.

Agreed ish , if its insulated up to spec a 1.5 curve should be ok , the trouble with customers with WC is most of them ( repeat most) like to still use programs and turn them off and on , instead of leaving them on.

 

[Julian Such]

I think I understand the principle behind WC and leaving it on but we are used to the heating switching off when we go out through geofencing. Modern family with changing schedules all the time which made Tado so good. I have picked this up with Viessmann and will update although I understand that the V3 Tado is fully compatible with the Viessmann. Let’s see what tech support says.

 

[999]

keep us updated, im always intrested in listening to what folk find works best for them regarding WC and smart controls

 

[Julian Such]

THis is a minefield!!, going from a 20yr old Valiant boiler which was perfect with the Tado to the Star Ship Enterprise! My layman guess is that The Tado is saying Heat Please and the Viessman is Saying Slowly Slowly, you cant rush these things! It is melting my brain to think that we would have the boiler on when we are not there!!

 

[999]

Why don't you disconnect the Tado and try out the weather compensation on its own before spending more money on another Tado system.

 

[Julian Such]

#Update. Viessmann advised that the Tado is doing nothing (opening valves). The heat request is generated by the WC. But as my fitters have fitted a two pipe system the HW will struggle to reach temp once it gets warmer outside. Furthermore whilst the Tado closes the valve the boiler still wants to fire. So the solution would appear to be 1, fix the four pipe solution 2, if I want to keep geofencing get a Tado V3.

 

[999]

Why wasn't the 4 pipe system utilised when it was fitted ?

 

[Julian Such]

Thats a question for my Viessmann approved fitter?

 

[999]

Using 2 pipe is no good if your using weather compensation as the hot water won't get to temperature as quite rightly pointed out by Viessmann.