Need help on gas calculations when comparing bills

ginamccon

Can someone please help me. My mother in law had just shown me two gas bills from two different companies and I can't explain why one is so high for the units used. Can someone explain?

Bill 1 is from eon, she used 135units which they convert to 1511kWh using this calculation, 135units (cubic metres of gas used) x conversion factor 1.02264 x calorific value 39.4 divide by 3.6 to get killowatt hours = 1511

They charged primary units 257kWh at 7.519p = 19.32
secondary units 1254kWh at 3.157p = 39.59
Total bill £58.91 not including vat or other discounts

Bill 2 is from southern electric, she used 79units which they convert to 2508.57kWh using this calculation 79units x factor 100 x correction factor 1.02264 x conversion factor 0.0283 = 228cubic metres x calorific value 39.5 divided by conversion factor 3.6 = 2508.57wkh

They charged primary unit 1143kwh at 4.310p = 49.26
secondary unit 1365.57kwh at 3.240p = 44.24
Total bill £93.50 not including vat or other discounts.

What I dont get is a unit is a unit read from the same metre. Eon say a unit is one cubic metre of gas, yet southen electric has to do a calculation to find this. How can 79 units equal 2508.57kwh for one company and 135units equal 1511kwh for another?

Can anyone answer this for me please as its been driving me mad.

kjsmith7

It looks like Eon are billing your mother in law on a metric or m3 or five black digit (and the rest in red) meter, which means the 'units' (or the difference between the two meter readings) are already 'metric'. It appears Southern Electric are billing your mother in law on an imperial or ft3 or four black digit (and the rest in red) meter, which means the 'units' need to be coverted to 'metric'. I've tried to explain that as simply as I can

Check the meter and see how many black digits there are, and whether 'ft3' or 'm3' is printed on the meter. If it is ft3, or imperial, then Southern Electric are correct. If it is m3, or metric, then Eon are correct. Either way, you'll need to contact the supplier in question to get the meter details updated. Hope that helps

ginamccon

Thanks so much, you truly are a star, that makes such sense. Ill go over and check the meter tomorrow and hopefully get her some money back as I'm hoping the metre is metric as its 5 years old.