Is the Viessmann Vitodens 100-W 26kW a combi, system or regular boiler?

If you are searching for a combi boiler for your house or flat, the Viessmann Vitodens 100-W 26kW is certainly one to consider.

Traditional boilers have one or more large tanks in which they store either heated water or water to be heated later. Manufacturers originally introduced combi boilers to the market in the 1970s to enable homeowners to save space - UK residential properties are among the smallest in the Western world.

Combi boilers don't need these tanks because they draw water directly from the mains and instantly heat it on demand thanks to the technology inside the boiler. Combi boilers then distribute this hot water to your home’s taps and radiators when needed.

The most significant disadvantage of combi boilers is that they are not ideal in larger homes where multiple people might want hot water at the same time – for example, if someone is having a shower while another wants to wash dishes in the kitchen. This is because combi boilers have a maximum volume of water that they can heat. When two people want hot water at the same time, the water temperature, pressure and volume delivered to both points drop.

Is a Viessmann Vitodens 100-W 26kW combi boiler suitable for my house or flat?

Whether this Viessmann Vitodens 100-W 26kW Combi boiler is right for where you live depends on its size or what its "output" level is. Size does not mean its physical dimensions, however - it means how powerful it is.

The output of a boiler is measured in kilowatts and indicates how much energy it can use to heat the water needed for your radiators, taps and showers. The greater the output, the more water it can heat.

A boiler whose output is too high will give you hot water and warm radiators but also higher gas bills, whereas a boiler whose output is too low will result in cheaper gas bills but the water might not always be as hot as you want it to be.

The output of the Viessmann Vitodens 100-W 26kW combi is 26 kW, so which types of property would this model be appropriate for?

To most experienced Gas Safe engineers, the Viessmann Vitodens 100-W 26kW combi Vitodens 100-W would be most suitable for smaller homes and apartments with up to 10 radiators and one bathroom.

If you are thinking about installing a combi boiler like the Viessmann Vitodens 100-W 26kW in your home, you should consider flow rates as well as output rates. This Viessmann Vitodens 100-W 26kW Combi boiler's flow rate is 12 L/m.

The flow rate indicates the maximum volume of water (measured in litres per minute) that your boiler can heat up and send to your radiators, taps and showers at any one time. The more taps and showers that could be in use simultaneously or the greater the number of radiators you have, the higher the flow rate you need.

However, you should establish what the mains pressure is at your property as a combi boiler can only heat the water that comes into your home.

For example, if your mains pressure is 12 litres per minute, your boiler can only heat and distribute hot water at a rate of 12 litres per minute even if it has a higher flow rate capacity. Typically, a power shower will require 10 litres of water per minute.

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.

Making space for the Viessmann Vitodens 100-W 26kW

The Viessmann Vitodens 100-W 26kW boiler is 455 mm high, 595 mm wide, and 800 mm deep.

Is the Viessmann Vitodens 100-W 26kW non-condensing or condensing?

The Viessmann Vitodens 100-W 26kW is a condensing boiler – we recommend to all clients that they choose the very latest condensing boilers because their efficiency continues to improve year after year.

Condensing boilers recycle heat from both water vapour condensation and flue exhaust gases via a secondary heat exchanger. With this heat, it performs other tasks like warming up colder water returning from your radiator without having to use more gas.

You will save money on your gas bills every year by choosing a condensing boiler as well as benefitting the environment.

How does the Viessmann Vitodens 100-W 26kW combi boiler rate environmentally?

Many homeowners are becoming increasingly concerned about how they heat their homes and the impact it has on climate change and other important environmental issues.

Central heating creates 14% of the UK’s greenhouse gases. And in Britain's larger cities, gas boilers are responsible for dangerous levels of nitrogen dioxide emissions.

Do the available figures suggest that installing the Viessmann Vitodens 100-W 26kW combi in your property would be an environmentally friendly choice?

In the UK, by law, all boilers manufactured since April 2018 must have a SEDBUK “A” rating and operate to a minimum level of 92% energy efficiency. Prior to this, the minimum was 88% – 88/89% would score a "B" and 90% or more an "A" on the SEDBUK scale.

The energy efficiency rating measures the amount of energy a boiler consumes when it's in use and how much it loses on non-core operations.

Following testing, the Viessmann Vitodens 100-W 26kW was given an efficiency rating of 94% and a SEDBUK grading of "A".

The ERP, short for the Energy Related Products Directive, is a European directive aimed at encouraging manufacturers to create products that are environmentally friendlier at all stages, including during manufacturing, when the product is in active use, right through to the point of final disposal.

The Viessmann Vitodens 100-W 26kW has a rating of "A" for heat and "A" for hot water production.

How long am I covered by the warranty for if the Viessmann Vitodens 100-W 26kW breaks down?

The Viessmann Vitodens 100-W 26kW boiler comes with a parts and labour warranty of 5 years.