I have no other gas appliance so unsure what to-do, i have OVO smart meters so could they be sending false data?
Best answer by Mw2870
Updated 17/09/2020 - See the info below on possible reasons for usage when the house is empty. See this guide for how to test for a fault meter.
I was interested in your post as I have also been looking at my gas consumption when I am not at home since my Smart Meter was installed.
On days I am not in the house for a whole 24hour period, MyOVO shows that the Gas cost for the day was £0.33. This seems to be consistent across the month.
This is made up of 28.77p standing charge and then 1.4 kwh of use @ 2.66p per kWH.
So 32.494p in total (I guess My OVO always rounds up in the graph).
So I was curious as to what is using the 1.4 kwh of Gas.... I have two Gas Appliances, a Vaillant Combi Boiler which does hot water and heating and a gas hob.
Now I know for sure the hob wasn't turned on, and I too have a Nest system so I know that the heating wasn't turned on at all (from the history in Nest).
So I have three theories
1) The Boiler occasionally uses a tiny bit of gas? Some sort of maintenance safety feature...
2) I have the worlds smallest gas leak
3) The meter is creeping when no gas is being used
I plan to test these theories by switching the boiler off completely and seeing if I get the same result next time I go away.