Oil boilers


Oil boilers are the traditional alternative boiler choice for the estimated 4.3 million households in the UK which are not connected to the UK’s gas network.


Viessmann oil boilers work in much the same way as gas boilers, the only difference being that they use oil as the fuel to heat the inner pipes and water, as opposed to gas.


By using a Viessmann condensing boiler to convert oil into heat you will be making an active contribution towards using resources efficiently and saving energy. This is because like our gas boilers, Viessmann condensing oil boilers feature an unbeatable high efficiency of 98 percent (relative to the gross calorific value (Hs)) and are also equipped for the future. All Viessmann condensing oil boilers are designed to be able to accommodate a changeover from fossil oil to fuel oil mixed with a certain percentage of bio-oil, which means that they can be run partially on renewables.


Which Boiler Do I Need?

At Viessmann, we offer a comprehensive range of boilers for all kinds of applications. Whilst our range is varied, we appreciate that it can make it difficult for you to know which boiler is right for your home. This is especially true if you have minimal knowledge of boilers, or if you have never purchased a boiler before. To overcome this problem, here we have put together a handy guide to selecting the right boiler for your home.

Questions to consider:

How big is your property?

The size of your property will be one of the most important considerations when it comes to selecting the ideal boiler. There is little point in choosing a high output boiler designed to provide heat to 15+ radiators when you live in an apartment with only a few radiators.

The boiler sizing for your home is matched to the heat it would lose on the coldest day of the year. Your Viessmann Trained Installer will calculate your homes heat loss and recommend the boiler size needed to replace this loss.

How much space do you have available?

Space is another important consideration. If you live in small property such as an apartment, then a combi boiler will be the obvious choice of boiler. This is because all of the components are contained within one unit and there is no need for a separate hot water tank. If you live in a bigger property and will require greater quantities of hot water, a system boiler and a separate hot water cylinder will be a more suitable option.

Will you need planning permission for a flue or chimney?

If the answer to this question is yes, it may be that biomass boiler will not be the option for your home.

Is it easy to find an oil or wood pellet supplier in your area?

Unlike gas boilers which utilise the gas supply you have connected to your property, oil condensing boilers and biomass boilers are dependent on fuels which will have to be delivered to your home by other means, i.e. road. Whilst there are many oil and wood pellet suppliers operating across the UK, if there is not one in your local area, fueling the heating system in your home come prove challenging.

 
New boiler checklist

Fuel type

At Viessmann, we offer boilers utilising three different fuel options. These are gas, oil and biomass. All of our heating systems are also compatible with Viessmann solar thermal technology, this allows you to utilise the free energy provided by the sun as a backup for your DHW heating and central heating backup. Not only does this allow you to benefit from lower energy consumption, it also allows you to look forward to lower monthly energy bills.

When it comes to selecting the right fuel type for your home, there are a number of considerations to be made. The biggest question is are you one of the 4.3m households not connected to the UK’s gas network?

If this is the case, there are a number of options available to you. You can either utilise one of our gas boilers, or you can look to one of our oil or biomass boiler options.

Gas boilers

All of the gas boilers available from Viessmann are gas condensing boilers. By choosing a gas condensing boiler from Viessmann, you will be making an active contribution to the environment due to the unbeaten high efficiency of 98 percent found across our range.

All of our gas condensing boilers can be used in conjunction with Viessmann solar technology. Equipped with Viessmann system technology, this ensures everything in your heating system works together in harmony and can make use of the renewable energy options available.

Advantages  

  • Gas is the UK’s most popular boiler fuel type
  • It is a convenient fuel source, as the majority of homes in the UK are already connected to the gas supply
  • No storage tank is required
  • Unlike some other types of fuel, with gas there is no need to pay for your fuel in advance. Instead you can either choose to pay quarterly or pay via monthly direct debit
  • Gas is one of the cleanest non-renewable boiler fuel types

 
 
Considerations 

  • It is not an entirely green fuel source as it produces carbon dioxide when burned
  • Installing a gas boiler if you have never had one can be expensive

 
You may choose a gas boiler for the following reasons: 

  • You already have a gas supply
  • You want a heat generator with a good price/performance ratio
  • You know that gas condensing technology with biogas has a firm future 

Oil boilers

Oil boilers are the traditional alternative boiler choice for the estimated 4.3 million households in the UK which are not connected to the UK’s gas network.

Viessmann oil boilers work in much the same way as gas boilers, the only difference being that they use oil as the fuel to heat the inner pipes and water, as opposed to gas.

By using a Viessmann condensing boiler to convert oil into heat you will be making an active contribution towards using resources efficiently and saving energy. This is because like our gas boilers, Viessmann condensing oil boilers feature an unbeatable high efficiency of 98 percent (relative to the gross calorific value (Hs)) and are also equipped for the future. All Viessmann condensing oil boilers are designed to be able to accommodate a changeover from fossil oil to fuel oil mixed with a certain percentage of bio-oil, which means that they can be run partially on renewables.

Advantages  

  • The price of oil has continuously been falling over the past few years
  • Oil is a highly efficient fuel, meaning that you get a good return on every unit of energy
  • Viessmann oil condensing boilers utilise the hot flue gases which would have otherwise wasted in a standard boiler, enabling them to achieve high efficiencies of up to 98 percent
  • Easy to use
  • Quiet operation
  • Suitable for use with Viessmann’s solar thermal systems 

Considerations 

Oil has to be delivered to your home by road, so it is important to carefully monitor
how much you have left in order not to unexpectedly run out

You will need an oil storage tank, so will need to ensure you have the space for this to the exterior of your property

Oil boilers and oil storage tanks should ideally be serviced on an annual basis

Viessmann oil condensing boilers are floor standing, so you will need to consider the space this will take up in your property

The hot water flow rate can be lower than a gas combi boiler 

You may choose an oil boiler for the following reasons:

  • You have an oil tank or an appropriate room
  • You have heated with oil before
  • You want a heat generator with a good price/performance ratio
  • You know that oil condensing technology with bio-oil is futureproof

Biomass boilers

Biomass boilers are a more eco-friendly alternative boiler choice. Sometimes also known as wood boilers, they are fuelled by wood pellets, chips or logs in order to generate heat.

An efficient boiler choice, by installing and using a biomass boiler within your home you will be saving the environment and saving on your energy bills.

The carbon dioxide given off by wood pellet boilers is similar to that absorbed by new plants, meaning they are a sustainable boiler choice. However, unlike gas and oil boilers, biomass boilers generate ash from the wood which they burn, so they will need to regularly emptied.

Advantages  

  • An eco-friendly boiler choice - powered by a sustainable fuel source, using wood in a biomass boiler will not produce environment harming carbon dioxide emissions. Instead, the level of carbon dioxide emissions is equivalent to the level absorbed by new plants
  • Wood fuel is very cost effective - made from leftover wood material, wood pellets are very cheap to produce and to purchase
  • On average, a biomass boiler costs £600 to run each year
  • Biomass materials are easy to store

Considerations 

  • Larger initial outlay - our biomass boilers are more expensive to initially purchase than our gas and oil boilers, however, this is outweighed by the annual fuel savings of the course of the boiler’s service life
  • Biomass boilers require regular maintenance - unlike gas or oil boilers, a biomass boiler will generate ash from the wood which it burns for fuel. This will need to be emptied on a regular basis otherwise you run the risk of the boiler shutting down
  • Our biomass boilers are typically slightly larger than our gas and oil boilers, so you should consider the space you will need in your home to accommodate the unit
  • Fuel storage - the storing of wood pellets or logs will also require a large amount of storage space, so you should consider the space which will be required to store this fuel


You may choose a biomass boiler for the following reasons:

  • You have a storage room available
  • You have enough space for a buffer cylinder with capacity of up to 1000 litres
  • You want to be independent of oil and gas, and a higher investment outlay will not be an issue

 
The types of boiler offered by Viessmann

Conventional boilers

Viessmann conventional boilers are boilers which use a storage tank, which holds gallons of water, to supply hot water to your home. Once the stored hot water runs out, you will need to wait for this to be refilled before it can be used again.
If you choose a conventional boiler, you will need more space within your home to accommodate this. This is because the hot water cylinder will need to be connected to cold water storage tank in the loft.

Combination boilers

Viessmann combination boilers, or combi boilers, work by providing hot water directly from the mains without having to be connected to a storage tank. As a combi boiler provides hot water at mains pressure, it allows you to use a shower without the need for an additional shower pump.
A combi boiler is an ideal choice for smaller properties such as apartments, where there is limited space, as all of the components are contained within one unit and there is no need for a separate hot water tank.

System boiler

Viessmann system boilers work by directly supplying hot water to the radiators in your home and a hot water storage cylinder. With a system boiler, the majority of the major components of the heating system, such as the pump and expansion vessel, are contained within a single unit. This makes installation simpler and also simplifies servicing.

System boilers are an ideal choice for properties with more than one bathroom or those who require more hot water than a combi boiler can provide.