vonnie1: so why such a big difference in useage?
Please can someone help me as I feel sick at the thought of paying a DD of £220!!
Hard to say based on the information. £200/month does seem a lot but £70/month is probably well low for the winter period.
You say you have done nothing different. I assume you have gas central heating. If so you wouldn't need to do anything different for the room stat to make a big difference depending on outside temperature.
The issue is whether the bill is right or not. How do you know a mistake wasn't made when the letting agent submitted your read? What happenned to the first quarterly bill? Are you on a Npower tariff with seasonal weighting of primary units? Are you on a Npower tariff which doesn't pay any discount until after 12 months? What about the electric readings?
I'd pay less attention to the useage breakdown. It can't be accurate on a monthly basis if the only readings are 6 months apart. Ditto the April to May reading is a very short period, in fact it's only 12th May today, not even mid month.
Concentrate on the total useage and why Npower think the debit is £791. If you tell me the readings and your tariff I might be able to help more.