New Boiler advice

Terrylw1

Some types of heating tend to contribute to higher usage such as underfloor or undercrop (thats won't be you!!!) but it does depend on all the other factors as Cardew has pointed out.

I agree. I think there is a good chance the conservatory is the issue. Suggest try what Cardew has stated as it could resolve this. Your meter dials will do as much as a monitor for that alone if you can turn the rest off.

Plenty of ways you can check this, even by turning it off for a couple of hours and monitoring readings in either side would give you an idea of how much you would use without the heating.

From there though it's more about changing how he uses it.