Knowing whether you need a direct or indirect cylinder is vital when looking to purchase one. Although the difference isn’t hugely complicated, it has a massive impact on the way the water is heated. Many people get confused at whether they need a direct or indirect cylinder and usually leave it to their plumber, however hopefully this will clear some problems up.
Direct water heaters are simple. They heat the water directly, or in simpler terms they heat the water themselves. All direct cylinders have an element inside of them, which are typically 3Kw, that heats the water up directly. The elements are usually thermostatically controlled, heating the water up once the overall temperature has lowered below a certain point. Typically, most direct cylinders will come with the recommended amount of elements, however some ranges do allow extra elements to be installed. The amount of elements in a water cylinder determine the rate at which the water will ‘recover’ back to its optimal temperature and maximum capacity. To read more about this click here.
Indirect cylinders are the opposite of direct. They do not heat the water directly. The main provider for heating the water inside the cylinder comes from an external source. This could be a gas boiler for example, and this is linked to the cylinder, but no water from the gas boiler ever comes into contact with the water inside the cylinder. The water from the gas boiler is heated up, then sent around a coil that runs through the indirect cylinder, whic h in turn heats the water up. Some indirect cylinders actually have an element inside, but this is just used to boost the speed of the heating process.
If you have any unanswered questions on direct or indirect cylinders, please give us a call on 01934 253600.