Radon mitigation systems: is your home safe? Here is all you need to know about replacing your boiler. All plumbing businesses listed in the watersafe online directory are members of a water industry-backed approved contractors’ scheme in the uk. Why use ahp boiler services for all your boiler and central heating needs? They have a boiler, a hot water cylinder often fed by a cold-water storage tank in the loft and a feed and expansion cistern in the same location. Q how much will a replacement.