The use of boilers and water heaters is the most common form of central heating and process heating throughout the world. The process is fairly simple, a body of water is heated via combustion or another energy source and the resultant hot water is used or stored as required. Condensing boilers are normally preferred due to their advanced efficiency but in certain situations a conventional alternative is required. The initial cost of outlay is often a consideration when opting for a conventional boiler over the longer term cost saving efficiencies of condensing technology. Ease of installation or overall output can also be influencing factors.