A direct cylinder heats its stored water with its own heating element. An indirect model receives heat through an internal coil.
Stored Hot Water for Direct and Indirect Systems
Stored hot water has to meet demand at the taps without taking over the plant room. MacBlair lists direct and indirect unvented cylinders from Warmflow and Albion, along with solar-indirect and twin-coil models. Capacities visible on the page run from a compact 90-litre direct model to 300-litre indirect options.
A direct cylinder heats stored water using its own element; an indirect cylinder takes heat through a coil from another source. Twin-coil versions accommodate two heat sources where the system is designed for them. Match the cylinder type to the boiler or heat source, the number of outlets and the available installation space.
Check dimensions, recovery requirements, connection positions and the manufacturer’s supplied safety components before ordering. Unvented-cylinder installation and servicing need a suitably qualified person. The new cylinder also needs compatible pipe fittings and may feed several showers at once, so incoming water performance matters as well as tank capacity.
Cylinder FAQ's
Consider household demand, simultaneous outlets, recovery time and the heat source. An installer can size the system.
Its two internal coils allow two compatible heat sources to transfer heat into the stored water.
No. It is fed from the mains, but the incoming supply must provide enough flow and pressure.
Installation involves safety controls and regulatory requirements. Use a suitably qualified installer.