Wetback systems are generally a pipe arrangement that fits in the back of the firebox. Water from your hot water cylinder is circulated through these pipes, sometimes by a small pump, and is heated using some of the heat from the fire. These systems provide water heating and reduce your energy costs.

Wetback systems only really provide substancial contribution to water heating in cold climates where a lot of space heating is used. Almost all solid fuel appliances can be fitted with a wetback water heating system that will either provide a majority of the households hot water requirements. However, the performance of the system can be affected by the quality and type of fuel being burnt, the amount of time the fire is operating, the distance between the appliance and the hot water cylinder and the average air control setting.

Most wetbacks work on the thermosiphon principle. The hot water cylinder should be installed as close as possible to the heat source in these systems to minimise heat loss. Some systems use an electric pump to circulate the water, allowing the cylinder to be placed further away from the heat source. In these systems, open venting is required.

To see out wetback hot water cylinders, see our wetback cylinders page.