1. Water Heating - a direct system for domestic hot xxwater.

Many stoves offer a water-heating facility. The simplest systems usually deliver an output equivalent to an immersion heater (2 - 3kW, or 7,000 - 10,000 BThUs) and will meet most household needs for bath water and washing-up.
XXBefore opting for such a system you should consult your installer to make sure that the location of your domestic hot water tank is suited to such an arrangement.
XXLow output boilers operate on a 'gravity' system whereby water is made to circulate round and round continuously between the boiler and the storage tank, driven by the density differences between the hotter and cooler streams. The force is weak and only works well when the tank is reasonably close to the boiler, is at a higher level than it, and the two are inter-connected with pipes at least 1" (25mm) in diameter. The pipes also need to be well insulated so that the temperature (and density) differences between them are maintained.
XXIf you are simply replacing an earlier system with a new one, most of these considerations should already have been addressed.
XXThe illustration at right shows a direct system – in other words the water coming out of your hot tap has been heated directly by the fire while passing through the boiler. For this reason the boiler must be made from a rustless material otherwise it would corrode rapidly and flakes of rust would come out of your hot tap.
XXTo prevent this from happening, boilers for direct systems are manufactured from copper or stainless steel. If they are made from mild steel or cast iron lined they must be lined with glass or vitreous enamel.