Are you eligible for the boiler replacement allowance? do you want to request quotes for free and with no obligation? if yes, complete the form on the top right of this post and our team will provide you with up to 4 suppliers that best suit your needs. We're your daily dose of science, conversation and medicine this is the scope, university of utah health sciences radio. While g-rated boilers can achieve anywhere between 50-70% efficiency, a-rated models have to be at least 88% efficient to.