Is the Viessmann Vitodens 100-W 35kW boiler a combi, regular or a system boiler?

The Viessmann Vitodens 100-W 35kW boiler could be suitable for your house or flat if you are looking for a new combi boiler.

Traditional boilers have one or two tanks - one holds hot water to keep it warm and the other water for later heating. Because UK residential property is among some of the smallest in the world, manufacturers introduced combi boilers and the heat pumps that go in them in the 1970s to reduce the amount of space boilers needed to take up.

The hot water needed for your radiators and taps is available on demand when you have a combi boiler. Combi boilers use technology located within the boiler to heat cold water, which it draws from the mains, and to distribute hot water where it's needed around your home.

A combi boiler, however, has the disadvantage of a maximum capacity for the amount of water it can heat. The result is that if someone uses the shower while another uses a hot water tap simultaneously, the amount of water reaching each point falls, causing water pressure to drop.

Should I install a Viessmann Vitodens 100-W 35kW combi boiler in my house or flat?

Whether this Viessmann Vitodens 100-W 35kW Combi boiler is right for where you live depends on its size or "output" level. Size does not mean its physical dimensions - it means how powerful it is.

The output level of a boiler tells you how much power it has to heat the water coming from your taps and warming up your radiators. The higher the output level, the greater the volume of water it can heat up.

If the output (measured in kilowatts) is too high, you'll pay higher gas bills and your water will be piping hot. Too low and the water coming out of your taps and being fed into your radiators will often be lukewarm.

The Viessmann Vitodens 100-W 35kW combi outputs at a maximum of 35 kW, so which types of property would this Viessmann Vitodens 100-W 35kW Combi boiler be appropriate for?

A PlumbProud heating engineer would recommend that this Viessmann Vitodens 100-W 35kW Combi boiler be installed in larger properties including detached homes with 15 or more radiators and two or more bathrooms.

Flow rates are important when choosing a combi boiler as well as output rates.

A combi boiler's flow rate (measured in litres per minute) describes how much water it can instantly heat then distribute to the taps and radiators in your home - you will need to factor this into your decision on a new combi boiler. This Viessmann Vitodens 100-W 35kW Combi boiler's flow rate is 17 L/m.

If you have a lot of radiators and bathrooms in your home and there's lots of demand within your household for hot water at the same time (like morning or evening showers and baths), you'll need a boiler with a high flow rate.

However, it's not quite that simple. If your local mains water pressure is low, you're not going to gain any benefit from choosing a combi boiler with a high flow rate because that higher flow rate doesn't mean it can draw more water from the mains pipes.
When our engineer comes out to quote you, they may recommend that you choose a heat only boiler or system boiler instead if your family's demand for hot water is higher than normal.

Viessmann Vitodens 100-W 35kW - size in millimetres

The Viessmann Vitodens 100-W 35kW measures 455 mm in height and has a width of 595 mm and a depth of 800 mm.

Is this Viessmann boiler condensing or non-condensing?

Because of their increased energy efficiency, we recommend to all customers that they select one of the latest condensing boilers. Condensing boilers capture the heat from water vapour condensation and flue exhaust gases and recycle that heat to warm water entering the boiler (for example, from your radiators).

The Viessmann Vitodens 100-W 35kW is a condensing gas boiler and choosing this model will result in a likely substantial reduction in your fuel bills, particularly if you're replacing an older, inefficient, non-condensing boiler.

Is the Viessmann Vitodens 100-W 35kW combi boiler good for the environment?

As more of us are increasingly concerned about climate change, how we heat our homes and its impact on the environment has become an issue of importance to homeowners.

Nitrogen dioxide emissions in Britain's largest cities are at dangerous levels and this has been caused by gas boilers. In fact, 14% of the UK’s greenhouse gases are produced by central heating.

If you decide to install a Viessmann Vitodens 100-W 35kW combi in your home, will you be helping the environment with your choice? Let’s have a look at the figures.

Boilers manufactured and installed in the UK are assigned energy efficiency ratings following testing to an agreed set of standards. These scores indicate how much energy the boiler uses and how much goes to waste when it's in operation.

By law, boilers must achieve a SEDBUK rating of "A" subject to achieving a minimum of 92% energy efficiency. Prior to April 2018, the minimum was 88% (88% and 89% on the SEDBUK are graded "B" and 90% and above is graded "A").

The Viessmann Vitodens 100-W 35kW was awarded an efficiency rating of 94% with a SEDBUK band rating of "A".

The Energy Related Products Directive (ERP) was introduced in 2015 and it applies to all products that consume energy throughout their lifetime, including during the manufacturing process and at the point of final disposal.

The purpose of the ERP is to ensure that companies create products that are kinder to the environment by reducing both the energy they use and the harmful emissions they produce.

The Viessmann Vitodens 100-W 35kW has an ERP rating of "A" for heat and "A" for hot water production.

How long is the warranty offered by the manufacturer for the Viessmann Vitodens 100-W 35kW boiler?

The Viessmann Vitodens 100-W 35kW boiler is provided with a parts and labour warranty lasting 5 years.