Home Assistant is a home control software for phone and computer. Shelly PM mini 16A Smart Power Meter that is very small and talks WiFi. $14.49 amazon.

I want to check the health of the gas furnaces in several houses/buildings. I am using Shelly Power Meter. I can't really measure the amount of gas, but I can know how long/much the gas is on. I really want to know if the furnaces are working and what percentage of time they are on. 100% on is not good and 0% on cold days is not good.

Here is a picture of one cycle of the furnace, power used. (forced air) At first start a small fan blows air through the fire box. 30W, then a 370W igniter comes on to light the fire. Gas is turned on at the same the igniter is turned off. The temperature starts up. (green line) When the fire box is hot the big fan starts. (800W to start 500W running) When the house is warm the gas is turned off and the small fan is off. The temp drops to a point where the big fan turns off. Then the temp slowly drops more.

If the furnace needs more than one attempts to start, then I need to work on it. At five attempts the furnace latches up and will not work. I have not tried it yet, but I think I can detect failed turn attempts. I think I can calculate gas usage.
For now I just want to know what percentage the furnace is on. I also want to look for power usage of 5W to less than 100W. This indicates a failure.


Wanted to share today's project. Last week I started measuring the electricity used to heat the chicken house and dog. (electric heat) We have problems with heat lamps burning out. I can easily see how many bulbs are pulling power.
RonS
---edited---
Today's graph. Cold and wind so 20% usage at night. By 11:00 the heat demand is down.

 

Being a Mac user, I use HomeKit automation. Similar tools are available such as power-monitoring switched outlets.

My Ecobee thermostat, which works with HomeKit but does not require it, logs quote a bit of HVAC data:

 

A Very interesting post, but I don't see any question.