Help me understand Vaillant code and flow temperature

[icchis]

Hello,

I have an ecotec plus 832 and I need some help to understand those value:

D.20 Max. DHW temperature target value - currently set to 55C
D.78 DHW max. flow temperature - currently set to 55C

Also I set the D.71 Max. heating target flow temp to 65C.

In the front panel and the VSmart app I have 65C for heating and 55C for water, advanced algorithm and 1.9 as heating curve. The house reaches the 20C I want and maintains it.

I'm wondering if these parameters are right and what's the difference between DHW temperature target value and DHW max flow temperature.

Thanks

 

[The831Bunny]

Don‘t use the D codes to adjust Heating and hot water temperature. D.20 is maximum HW temperature. Set it to 65ºC and adjust HW temp to 50-55ºC on the vSMART app.

D.78 does not apply to a combination boiler, it’s for use with a cylinder.

You can adjust the maximum heating flow temperature in D.71 if you want, but setting it to 65ºC prevents your boiler from operating at a higher flow temperature request from your vSMART. There’s then a good chance your property won’t achieve the required room temperature with minus outside temperatures. Let the vSMART calculate the required flow temperature, if it achieves the room temperature easily, adjust the curve down by 0.5 and test it for a day or two. Take the curve down to a point you reach the desired room temperature within 90mins. You can help a vSMART operate correctly by increasing pump over run in D.1 to 10mins, making sure the thermostat is in an area which represents the required temperature, keep the stat away from cold draughts, sunlight or other influences of heat, and make sure most of your radiators are on in the property, not just one or two. If you want to save money, turn your vSMART down, not the boiler.

Hope that helps

 

[icchis]

Don‘t use the D codes to adjust Heating and hot water temperature. D.20 is maximum HW temperature. Set it to 65ºC and adjust HW temp to 50-55ºC on the vSMART app.

D.78 does not apply to a combination boiler, it’s for use with a cylinder.

You can adjust the maximum heating flow temperature in D.71 if you want, but setting it to 65ºC prevents your boiler from operating at a higher flow temperature request from your vSMART. There’s then a good chance your property won’t achieve the required room temperature with minus outside temperatures. Let the vSMART calculate the required flow temperature, if it achieves the room temperature easily, adjust the curve down by 0.5 and test it for a day or two. Take the curve down to a point you reach the desired room temperature within 90mins. You can help a vSMART operate correctly by increasing pump over run in D.1 to 10mins, making sure the thermostat is in an area which represents the required temperature, keep the stat away from cold draughts, sunlight or other influences of heat, and make sure most of your radiators are on in the property, not just one or two. If you want to save money, turn your vSMART down, not the boiler.

Hope that helps

Thank you for your explanation. Which temperature should I set D.71? The maximum and let VSmart manage it?

 

[The831Bunny]

Thank you for your explanation. Which temperature should I set D.71? The maximum and let VSmart manage it?

Set it to 75ºC that should ensure return temperatures wouldn't go over 55-60ºC in most cases in winter. Flow temperature reduction is mainly linked to the weather, not so much with room temperature, so make sure your location is correctly set in the app and it will pull in the nearest weather station info.

 

[icchis]

There is one thing I don't understand. I set the D.20 Max. DHW temperature target value to 65C and in the VSmart app the hot water to 50C but when I run the hot water, in the boiler I see 70C