Boiler Temperature Control on a Vokera Vision 30c

NGMAlva

I have just installed my Tado starter kit and I am really happy with it so far. My question is about the temperature control within the boiler itself.

I had imagined that the Tado would control the boiler temperature so that when the room temperature was below the value set at the Tado remote thermostat, the boiler would be activated and efficiently heat the radiators to sufficiently achieve the temperature set by the Tado remote thermostat and then turn the boiler off. Most of this happens however how efficiently it happens is still dependent on what temperature is manually set at the boiler. I initially manually set the boiler temperature to its lowest value thinking that this was now obscelete but it then took an age for the radiators to get a heat. Manually increasing the boiler temperature has now meant that the radiators heat up more quickly and so the boiler is not on for as long.

So my question is, is the manual setting of the boiler temperature still necessary (and if so, what is the optimal temperature setting) or if not, how should this be controlled by Tado?

Hope this is clear. Any help or guidance would be greatly appreciated.

Very best regards.

johnnyp78

Do you mean the maximum flow temperature? Tado won’t be able to control this unless it’s connected digitally with something like Opentherm or ebus. On a relay connection you need to set it yourself.

I’ve copied this from the Viessmann site: “In modern gas condensing boilers, for the boiler to work at its most efficient, the heat exchanger needs to be equal to or below the dew point temperature. The dew point temperature is a measurement that determines the humidity of air and is the temperature at which water droplets form in the heat exchanger. For gas boilers, the dew point is around 55 °C. This means that the water needs to be 55 °C or lower for your boiler to maintain its efficiency.”

The further below 55c the water is the more efficiently the boiler operates, but the slower the house will heat. If you increase the max flow temp above 55c the house will heat quicker but the boiler will use more gas to do it.

NGMAlva

Thanks very much johnnyp78 this is really helpful and clear. Think it is just going to take a little bit of tinkering to find that sweet spot between speed of getting the radiators up to temperature and the efficiency of the boiler in getting there. Thanks again, much appreciated.