Propane fireplace usage

Configuration
1

I have a propane gas insert fireplace which I can control via a Bond bridge. Outside I have a 60 gallon propane tank, which does not have any monitoring on it. If I know how many hours my fireplace has been on between propane refills, I can estimate how much propane it uses per hour. Say it can run for 100 hours, what I’d like is to get notified when I’ve hit that threshold.

What I can’t seem to find is a way to sum how long a switch has been on over a period of time. If I setup grafana, I’ll have the stats there, but no way to get that back into home assistant. Clearly the logbook has some sort of record of when the device is on/off, and something could query it every hour to update a sensor.

This seems similar to what some people are doing measuring energy usage per lightbulb. But before I can measure, I need to know how many hours it was on over a period from refill to refill.

2

I’m doing this successfully by using this sensor:

# Stove statistics
  - platform: history_stats
    name: Stove On Time
    entity_id: switch.xxxx
    state: "on"
    type: time
    start: "{{ now().replace(month=1, day=1, hour=0, minute=0, second=0) }}"
    end: "{{ now() }}"

Replace switch.xxxx with whatever your stove switch entity ID is.