Viessmann Vitodens 100-W Combi Boiler B1KC

[cmmaia]

Hello all!
I've just got a new Combi boiler installed and would like to clarify two things (I have heating off atm and DHW set to 50ºC (which is default).

- While using hot tap water, display shows it goes to around 64ºC. Shouldn't it be around 50 as per setting?

- In DHW, does it matter if water goes above 54 (or whatnot) in order to render condensate heat inutilised? Or does condensation heat-usage only applies to heating?

Regards and thank you!

 

[cmmaia]

Anyone? Thank you.

 

[JoshW]

The display on the boiler shows the flow temp of the boiler water, not the tap water. To output hot water at 50 degrees, the boiler will go higher than 50 especially at first when it has to heat up the heat exchanger surfaces. If you’re worried about achieving max efficiency you could turn down the DHW temp a couple of degrees but it probably won’t make much of A difference to your overall gas usage in reality.

 

[cmmaia]

The display on the boiler shows the flow temp of the boiler water, not the tap water. To output hot water at 50 degrees, the boiler will go higher than 50 especially at first when it has to heat up the heat exchanger surfaces. If you’re worried about achieving max efficiency you could turn down the DHW temp a couple of degrees but it probably won’t make much of A difference to your overall gas usage in reality.

Thank you for a clear, concise answer!