Electrical consumption of the Vietodens 100

[_Jeff_]

Hello there. Sorry for not being able to speak German to ask this question.

I live in Liguria (not a very cold region), the house now runs on a PV generator with batteries and the electrical consumption of my Vitodens 100 makes me a bit nervous 🐵 It is used only for domestic hot water production (not to heat the house): is it normal that it draws ~70-80 W most of the time, largely when we are not using hot water ? (it's about ~1.1 kWh / day). 

(each vertical graduation is 20 W, data of the day).

Take care,

Jeff

[Fiedel]

Hi Jeff,

please post the serial number (or photo of the sticker) of your Heater.

What voltage and freqency do you get out of your battery- inverter?

At the first sight, this should be not normal. You should make sure (or check) if any pumps

are runnig while the heater is not working on boiling water. In working condition it may be o.k.

How exactly is your meter? Did you compare the results with a energy- meter like this?

These cheap meters are exactly enough to have a reference.

Cordialità

Fiedel

[_Jeff_]

Hi Fiedel,

Thank you very much for your answer.

Here is a pict of the sticker of my Viessmann Vitodens 100-E AB1B:

Here are the voltage & frequency generated by my PV system:

It seems to be the circulating pump which is drawing ~70-80W on a nearly continuous basis, mostly when the boiler is not used:

The above data are for today, they are measured with the Emporia Gen 2 Vue (amperemeter with 16 channels inside my main electrical service panel), and checked with another hand amperemeter by Voltcraft.

What would be the use of these daily kWh ?

Is there a reason why the water should be circulated most of the day, in particular when not using hot domestic water and when the heater is not used to heat the house ?

Can I put a wifi circuit breaker or a Vitoconnect module on the heater to reduce its electrical consumption ? (I am using Home Assistant to implement automatic controls) 

Does Viessmann offer more (electrical) energy-efficient boilers ?

Ausgezeichneter Tag & Grüße aus Ligure,

Jeff

[Fiedel]

Your measuring system looks great!

The reason for running the pump very often could be the freeze- protection.

You cannot switch that off, but you could put a resistor to the outside temp.- sensor,

so that the outside temp looks warm to the controller. This disables the freeze- protection.

I would not use a wifi switch on the pump because of safety reasons: When the warmwater

boiling starts, the pump must run. Wifi ist not safe enough for that.

On the heater itself it is also not good: Every power on takes much energy and stresses some

components.

But you could change the pump- motor to a modern high efficiency- type. If you post a photo

of the pump, we try to show you a replacement motor.

[divanc]

Hallo Fiedel

Jeff hat einen Gaskessel, der draußen oder auf dem Balkon montiert ist, mit einer Pumpe, die in den Kessel eingebaut ist

 

im Boiler ist zusätzlich ein elektrisches Heizkabel eingebaut, so dass der Stromverbrauch maximal 107 W betragen darf.

https://www.viessmann.com/etapp/parts/de/7300/7423060

Schöne Grüße

[_Jeff_]

Yep, living on a battery, I tend to take care of each kWh vanishing into my domestic network 😅 ...I rapidly felt the need for a tool to track these (Emporia).

Here is the circulating pump fitted into my Vitodens:

Does "class H" imply a poor energetic efficiency ? 

Indeed, if there are more efficient alternative pumps (class A ?) for my Vitodens 100-E AB1B, I will change mine for one of them.

[_Jeff_]

Hello Divanc, actually my Vitodens is in the basement (between 8°C and 12°C these days) 

[Fiedel]

@divancVielen Dank!

@_Jeff_: You could use this pump motor. The Grundfos- type.

@divanctold us, that your heater has a "heating cable" that takes a lot of power,

because the heater is mounted on a outside wall. If this is true, you could  manage this

"freeze protection kit" with a wifi switch. If there is no frost, it can be switched off.

But you shold watch it with Home Assistant, because if it fails, the heater could be damaged.

[divanc]

Ciao Jeff

La vostra caldaia a gas è progettata per l'installazione all'aperto in fabbrica, quindi è protetta dal gelo con un cavo scaldante.
Se riesci a garantire temperature sopra lo zero nel tuo seminterrato, puoi provare a scollegare il cavo del riscaldamento.

La classe H sulla pompa indica la classe di isolamento.
 

 

saluti

[_Jeff_]

Danke Divanc
Ich bin mir sicher, dass der Kessel in der Garage weit über 0°C bleibt (der Batteriepark in der Garage misst die Temperatur), also werde ich schauen, ob dieses Frostschutzset vorhanden ist, um es abzuschalten. Die Umwälzpumpe läuft jedoch die meiste Zeit, ich habe sie viele Stunden lang gehört, als ich meinen PV-Generator in der Garage verkabelt habe. Der Heizkessel nimmt etwa 70-80 W auf (75% der Zeit), etwas weniger (60-70 W) und mit weniger Lärm, seit ich den Geschwindigkeitswahlschalter der Umwälzpumpe von II auf I umgestellt habe, wenn wir heißes Wasser zapfen und der Brenner anspringt (wie um 07:14:30 oder 07:14:45), steigt es vorübergehend auf 90 W, aber all das scheint weniger zu sein als die 107 W des Frostschutzheizungssets? Wenn dieses Frostschutzsystem von einem Temperatursensor gesteuert wird, muss es deaktiviert werden.

Ausgezeichnetes Wochenende !

[divanc]

Ciao Jeff

Se si desidera disattivare la funzione antigelo della pompa di circolazione, scollegare la sonda esterna e collegare una resistenza da 8 kOhm al posto della sonda.

Il cavo scaldante è collegato direttamente a 230 V secondo il progetto

Con queste conversioni, ti assumi tu stesso la responsabilità in caso di possibile congelamento del dispositivo.

saluti

[_Jeff_]

Thanks a lot Divanc for this simple hack, I will give it a try 1st, before possibly substituting the circulating pump.

[_Jeff_]

Hallo divanc,
Als ich den Temperatursensor durch einen 5-kOhm-Widerstand an den Klemmen 3 und 4 ersetzen wollte, stellte ich an dem betreffenden Dominostein Folgendes fest:

 

bedeutet das, dass kein Temperatursensor angeschlossen ist ? und dass der Frostschutz der Umwälzpumpe einen maximalen Widerstand sieht, also eine minimale Temperatur ?

In jedem Fall ordne ich meinen Widerstand wie folgt an ?

Ein tolles Wochenende !

Jeff

[divanc]

Hallo

Ich sehe, dass der Außenfühler überhaupt nicht an die Regelung angeschlossen ist, nur der Raumthermostat ist angeschlossen.
Die Frostschutzfunktion kann durch Sensoren ausgelöst werden
(Boiler oder WW), wenn die Temperatur am Fühler einen bestimmten Wert unterschreitet.

Grüße