Thanks for the comments so far...
Spoke to British Gas today, something about 4.2 units a day average, said our bill was high (but not massively apparently) and offered us a meter accuracy check that if it found nothing wrong would cost us over £700. Our quaterly bill for Nov 2012 to Feb 2013 was for £682.56 using 14666.59 kWh of gas. That is £56.88 per week or £227 a month just for gas!! The most recent bill is for £542.94 using 11349.57 kWh of gas. That is £38.78 per week or around £170 a month. This seems exceptionally expensive for a 3 bed semi. I've checked the serial number on the meter in case it's a billing mistake but it's the right one. I can't imagine what it is that is causing such high bills! Most people pay for a month what we pay a week!
Q. Are you on a Dual Fuel tariff with BG.
A. We are. We are going to check for a better tariff with BG though as we were on their essentials tariff (which has now stopped) and now we are just on standard.
Q. Have you checked to see if there's a better tariff using a price comparison site.
A. There are cheaper tariffs but we are in so much debt to BG we can't change.
1. How old is the boiler approx.
The boiler is an Ideal fitted 6 years ago.
2. Is the house double glazed.
Yes, with only one small single glazed in the bathroom.
3. Is your loft properly insulated with at least 100 to 200mm of insulation material.
The loft is insulated but we have been approached by a company who will upgrade it via a grant. They are also insulating the cavity walls.
4. Do your rads all work well, heating quickly and with no cold arcs across the rads.
They seem to be fine, all get very hot. They were cleaned and had new valves when the boiler was fitted 6 years ago. Some sort of inhibitor was used as well.
5. Is your hot water cylinder reasonably modern with a factory applied foam covering all over.
I don't know how old it is but it does have foam cladding all around it.
6. Is your boiler checked annually as this should ensure it's burning gas efficiently. If not, when was it last serviced or repaired.
British Gas service it annually. I dunno what the engineer did last service but it seems to get the water much hotter despite the settings being the same.
What to do??