Combi boilers: is a combi boiler the right boiler for you? Call us today on: or . Radon mitigation systems: is your home safe? Only gas at a cool temperature will be released and this can turn into water vapour the boiler will extract energy from this vapour also, ensuring efficiency is further improved. But the sales-like nature of this visit put me off could i save more elsewhere? Heats and loosens debris.