It has been mild, too much rain, but I think your new boiler and heating would explain the low bill. I have just input our meter readings we pay £45 permonth and now in credit during the winter months, OK it is only 18pence but credit non the less.
I have just had a dispute with the energy minister, Condems state ours bills are lower because of what they have put in place, however they companies have increased the standing charges, this is the disgraceful part of them trying to pull the wool over our eyes.