I recently noticed a tripling in average daily gas usage and am trying to tie down the cause. I have gas ducted heating underfloor, a gas hot water system and gas hob. With all those not operating, the gas meter reading was not moving. No smell of gas outside. The heating has not been used any more in the last few weeks compared to previous months. The only thing I can think of is that something could have changed when the ducts were cleaned a few weeks ago. Perhaps something was knocked. Anything else I should check? Thanks forxany suggestions.