Conventional Open Vent (Heat Only) Boilers

An ideal replacement for older boiler systems, our open vent gas boilers are designed to be installed on an open vented system.

All of our boilers are designed and built to the highest standards in line with our long-established reputation for creating excellent quality heating systems.

Defining the quality benchmark for other brands, our open vent boiler range offers the latest in heating technology and is focused on delivering energy efficiency. This means our appliances will help you to reduce your costs, save natural resources and protect the environment.

Often referred to as regular, conventional or heat only boilers, open vent boiler systems provide heating and hot water. These solutions usually comprise an ‘open vent’ and two water tanks in the loft space, a hot water storage cylinder and a separate pump. Common in older buildings, they can be ideal for households with multiple bathrooms because they are able to supply a lot of hot water at once.

In these systems, a cold water storage tank draws water from the mains supply and feeds the hot water cylinder. It also supplies a tank that keeps the water level of the central heating system constant. Unlike combi boilers, conventional boilers enable you to use multiple water sources in your home (such as taps and showers) at the same time without experiencing a drop in temperature or pressure.

Open vent boilers can be the right choice for a range of homes. For example, one of these heating solutions may be the best option for you if you are replacing an existing boiler of the same style and if you have an older radiator system. 

The pipework in these systems may not be able to cope with the pressure delivered by combi or systems boilers. So by opting for an open vent boiler, you will avoid potentially costly adjustments to the pipework and heating system in your home.

Conventional boilers can also be a good choice in properties where there are multiple bathrooms, and in areas where water pressure is low.

When you choose a Viessmann open vent boiler, you can be sure you’re getting an appliance that is designed and built to the very highest standards. All of the models in this range offer exceptional performance and reliability, and they are built to last.

 Featuring corrosion-resistant stainless steel Inox-Radial heat exchangers, they are also highly efficient, helping you to save money on your energy bills and reduce your carbon footprint. In addition, they are designed to have very low operating noise levels, meaning you’ll barely notice your boiler is there.

Each of the boilers in this range is smart home ready and can be controlled remotely via an optional app. So, you can control your heating environment from the palm of your hand, wherever you happen to be.

Here’s a recap of some of the other reasons to consider choosing one of our conventional gas boilers: