Heat Only Boilers

The boiler sector is awash with jargon and terminology, but at least most of it is straightforward and easy to understand. The clue is in the words.

Take Combination Boilers, which combine both the provision of hot water for central heating system and for the taps in the same process. When the radiators require hot water, the boiler fires up and provides it. You turn on a hot tap, the boiler gets going and its there. Hot water on demand and nothing is stored for later use.

Heat Only Boilers provide hot water at regular intervals which is then stored for later use by the central heating system and hot water taps. Also called Open Vent Boilers, these units are designed to produce the hot water and keep the hot water cylinder regularly topped up with water, ready for use.

By the way, they are called Open Vent because they operate within an open system. The cold water is usually supplied by a cold water feeder tank in the loft. This is opposite to a closed, or sealed system, used mainly by System Boilers. The water within a closed system is just that, locked within the pipework and fittings and sealed under pressure.

Heat Only boilers are primarily used in larger properties, mainly because they can store large amounts of hot water for use at a moment’s notice. A combination boiler, unless backed up by a separate storage unit, tends to struggle with houses that have a large number of bedrooms and bathrooms.

The obvious downside with Heat Only boilers is that they require more kit (a hot water cylinder and cold water feed tank for example) and more pipework, so take up more room and are thus more expensive to fit.

But, for anyone requiring a boiler that has the capacity to cope with a large property, they are the obvious choice.

Heat Only Boilers remain a popular choice for many people.