Hi Folks,
I’m fairly new to Home Assistant and also have very little experience of YAML or Python, so not a winning combination!
I have an oil boiler and I’m trying to work out how to set up a ‘time to empty’ calculation for the oil tank based upon the boiler run time. The boiler has a fixed oil flow when running so the flow is easy to calculate from the running time, which is measured from a binary sensor.
.
The calculation would be along the lines of;
Oil_Remaining_Volume = Oil_Starting_Volume - Oil_Consumed_Sum
Oil_Predicted_Empty = Oil_Remaining_Volume / Oil_7day_Average
I’ve created the following helpers;
Number entity, to input the Oil_Starting_Volume and allow easy reset after the tank is filled.
Template - Oil_Consumed_Today, based upon a relay measuring the boiler run time * oil flow rate
Date entity, to input the Oil_Fill_Date, planned to use to sum the individual Oil_Consumed_Today values between the Oil_Fill_Date and @now
I thought the statistics sensor package would work for calculating the Oil_Consumed_Sum since Oil_Fill_Date and to also calculate the Oil_7day_Average values but can’t get the statistics to work. Tried various combinations, none of which seem to get me anywhere.
Perhaps something like;
sensor:
- platform: statistics
name: “Oil_Consumed_Sum”
entity_id: sensor.Oil_Consumed_Today
state_characteristic: mean
max_age:
days: {{{ now() }} - “Oil_Fill_Date”}
sensor:
- platform: statistics
name: “Oil_7day_Average”
entity_id: sensor.Oil_Consumed_Today
state_characteristic: mean
max_age:
days: {{{ now() }} - xxxxxx} I can’t work out how to subtract ‘x’ days from the now() value.
Any thoughts or help greatly appreciated.
Thanks.