If your combi boiler is in a cupboard, the cupboard is no less than 780mm (h) x 460mm (w) x 380mm (d) and there is space of 600mm in front of the boiler. On an open-vented system, if the pilot flame is lit but you don’t have any heat or hot water, you may find the ball valve is stuck in the feed and expansion tank. No trip, travel or hidden fees. Phone: 01425 653889 | 07770770080. Basket totals are under the basket summary heading. Read our top tips to combat common.