Energy use, what does this tell me?

[ericmark]

The bars show how long the wall thermostat turned on the pump for, but not how long the boiler runs for, as it would have been cycling on/off and the mark/space ratio would change due to the rooms which the TRV's have turned on or off, so does it tell me anything other than the weather was cool.

 

[Lower]

If you tap each bar you can then see when the thermostat was calling for heat and see it cycling on and off. That is it though.

 

[ericmark]

At this time of year I often walk into the flat where the boiler is, and it is not running, but red light is on. With me since the boiler does not modulate, I could time how long run light is on, but it would not really help, if it's cold, I want heating on.

People with modulating boilers could not do even that, only way to measure energy used is to measure how much oil or gas is used, latter easy enough, but dipping oil tank not enough change day by day to measure.

I can see the point with gas, the boiler can extract the latent heat, but often it does not due to the way it is switched on/off. With OpenTherm the thermostat could work it out, as it tells the boiler output required, however not looked into if the display changes when using OpenTherm?

But at least with my oil boiler simply can't see the point of the display, what do it tell me?

 

[Lower]

At this time of year I often walk into the flat where the boiler is, and it is not running, but red light is on. With me since the boiler does not modulate, I could time how long run light is on, but it would not really help, if it's cold, I want heating on.

People with modulating boilers could not do even that, only way to measure energy used is to measure how much oil or gas is used, latter easy enough, but dipping oil tank not enough change day by day to measure.

I can see the point with gas, the boiler can extract the latent heat, but often it does not due to the way it is switched on/off. With OpenTherm the thermostat could work it out, as it tells the boiler output required, however not looked into if the display changes when using OpenTherm?

But at least with my oil boiler simply can't see the point of the display, what do it tell me?

It tells you how long the house temperature has been lower that the thermostat set temperature and gives a rough indication of how long the heating has been required per day. But its not detailed info.

 

[old duffer]

It tells you how long the house temperature has been lower that the thermostat set temperature and gives a rough indication of how long the heating has been required per day. But its not detailed info.

and then what?