heatonly
Heat-only (sometimes written heat only or heat-only) refers to heating systems and appliances designed solely to produce space heat, and in many contexts to boilers that provide central heating with hot water stored separately rather than on demand. The term is used in building services and HVAC to distinguish these systems from combination (combi) boilers, which supply both space heating and instantaneous domestic hot water, and from heat pumps that may provide both heating and cooling.
A typical heat-only boiler is part of a conventional or regular system that includes an expansion vessel,
Advantages of heat-only systems include straightforward compatibility with hot water cylinders, simpler integration with solar thermal
Installation, maintenance, and safety of heat-only systems are governed by local building codes and industry standards;