Viessmann rule to set heating curve (niveau and gradient)

Hello Community,

has someone create a rule that is setting the perfekt heating curve (niveau and gradient) that is calculated with the outside temperature?
in my case it have sometimes problems when the outsite temperature is going from 10+ to 0 ore less, than the flow temperature is to low ore to high for underfloor heating.
It’s a shame that you can’t fix the flow temperature.
Maybe there is a calculation that sets me the heating curve for every large temperature differences.

Maybe there is a heating expert in this forum who did something in this direction.

Kind regards,

I guess you have watched that german Video

oh yes :slight_smile:
i have not the skills for heating systems, so maybe someone can help me with that.

that would be useful for anyone who owns a viessmann heater ore another heater that is controlable.

Changing the values for niveau and gradient is possible, please see this Thread.
Back then I could only manage to use hard coded values, however those values were used by the system. Probably those values have to be set as strings.

Hi Martin,

I use the following rule which calculates a manifold setpoint temperature using a slope calculation.

rule weather_compensation_calc
	Item i_LookAheadTemperature changed or 
	System started
	var origin_flow_max_temp = 45.0 
	var slope = -1.2  
	var origin_flow_temp = 25.0 
	var origin_outside_temp = 15.0
	var intercept = origin_flow_temp - (slope * origin_outside_temp) 	
	var compensated_temp = slope * (i_LookAheadTemperature.state as Number).floatValue + intercept 

	if ( compensated_temp > origin_flow_max_temp ) {
		compensated_temp = origin_flow_max_temp

In my installation I am using the weather binding to check the forecast temp in 4-6 hours time rather than the actual temperature as my system takes a while to react. The origin flow/outside temp and slope can all be tweaked to give the best setpoint.

It seems to work well, although I am trying to work out a better way to measure the actual heat up time based on room heat loss/outside temp, etc to calculate the optimum start time.


1 Like