ᐅ Hot Water Issues with the Vitocal 200-S

Hello,

I am having issues with the hot water production of my Vitocal 200-S heat pump. The hot water only reaches a temperature of 43°C (109°F), although with a supply temperature of 55°C (131°F), a hot water temperature of 50°C (122°F) should be achievable. What could be causing this?

I have noticed that as soon as the supply temperature reaches 55°C (131°F), the heat pump switches off quite quickly.

Thank you very much

I just spoke on the phone with the contractor.
I was told that you contacted Viessmann, and Viessmann said that without the electric heating element, a maximum of 43 degrees Celsius (109°F) can be reached and that I should turn on the electric heating element.

But that doesn’t sound normal, does it?
With a flow temperature of around 55 degrees Celsius (131°F), you should be able to reach about 50 degrees Celsius (122°F) hot water, right?

Hello,

informatikerbw schrieb:
....I have noticed that as soon as the supply temperature reaches 55 degrees, the heat pump switches off quite quickly.

This manufacturer does not provide complete COP and performance curves for the usual supply temperatures for heating (35°C (95°F)) and domestic hot water (50 or 55°C (122 or 131°F)). One might suspect something unfavorable here.
According to the datasheet, supply temperatures up to 55°C (131°F) are reached. However, it is not revealed whether this is only possible with the help of the electric heating element.
The tabulated triple-point values (heating mode) are completely insufficient for an overall evaluation.

informatikerbw schrieb:
...But that’s not normal, is it?

Unfortunately, it is here. Depending on the proportion of domestic hot water production in the total energy demand, the overall annual performance factor is likely to be rather modest—hardly desirable.
Who planned this system?

Regards.

Hello,
I spoke with the technical support team at Viessmann today. They told me that a minimum of 48°C (118°F), possibly even more, is definitely achievable.
They advised me to read the temperature sensors after the heat pump switches off. I did that.
Here are the values I recorded when the heat pump switched off.
Outdoor temperature: 30°C (86°F)
Supply temperature, secondary circuit: 55°C (131°F)
Return temperature, secondary circuit: 52°C (126°F)
Storage tank temperature, top: 42°C (108°F)