I bought my first house in December and one thing I've noticed over the winter is higher than expected gas usage which I'd like to try and get down if at all possible. The house is a three bedroom (two plus box room really) semi-detached UK house built in the 30s if thats relevant. The previous owner had recently installed a new Ideal Icos HE24 combination boiler but with a standard thermostat and timer.
I'd like to replace the thermostat and timer with two programmable thermostats for upstairs and downstairs and use valves to control heating flow to the two zones. I've seen drawings on the internet showing this using a standalone boiler with separate pumps wtih each zone but am not sure if zones are achievable using combination boilers or whether I'd be placing stress on the boilers internal pump?
My thoughts so far involve one valve for the upstairs flow and one for downstairs flow, from what I've seen I don't need return valves as well?
Working with heating systems isnt something I've done before so I guess I may have some things wrong here but would be interested to hear peoples thoughts.