The energy efficient modena he combi boiler. A combination boiler, which is heating your home and hot water directly (rather than a hot water tank) has more moving parts that can break down condensing versions have also proved troublesome. See our great oil and gas offers over the cold season - they'll be sure to keep you warm! Clean-cut, professional technicians. Small families combis really work best when asked to provide heat for one need at a time so if you have several family members.