Calorific Value (CV) on gas bills

DPF8591

The m3 to kW/hr conversion on gas bills use an average daily CV figure, among other figures, to determine the amount of gas you have used in kW/hr's for any particular billing period. 
I know where to get this value, or at least I thought I did, until I changed suppliers recently. My previous three suppliers always quoted a CV figure exactly the same as the one printed from the National Grid UK website, (this would be the daily CV figures for a billing period added up then divided by the number of days). My new supplier's CV figure was slightly higher resulting in me being charged for more kW/hr's for the amount of m3 of gas used. This only resulted in me paying just over a £1 more for the month, but adding this up over the year multiplied by the number of customers they have will be quite significant. 

Having asked them where they get their CV figure they have been unable, or unwilling, to provide it. Before I escalate this I was wondering if anyone out there knows if there are alternative methods of determining the CV figure and if so, how? Or does anyone know of an alternative place to get the CV figure.

thanks in advance

JGB1955

I always understood that the CV varied according to season and region...which probably means you can't nail it down.

[Deleted User]

This is the only source of CV a data that I am aware of:

https://www.nationalgrid.com/uk/gas-transmission/data-and-operations/calorific-value-cv

Some suppliers have got into trouble with Ofgem in the past because they have tried to use a fixed CV in contradiction of the 2014 Ofgem policy. 

Personally, I would raise a written formal complaint using CV data from the link above. Remember, under Ofgem regulations, suppliers have to truncate the average CV to one decimal point; ie, an average of 38.99 has to be billed at 38.9. At the very least, the supplier has a duty to explain why the CV that they are using for billing purposes is different from your calculation. If you are unhappy with their answer, then refer the complaint to The Energy Ombudsman.