Boiler system types

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Boiler system guide

Combi Boilers

’Combi’ is short for combination, because the boiler manages two things in combination. It heats water and provides central heating to your home.

Combi boilers heat water as you draw it from the tap. They don’t need a water storage tank because the boiler’s connected directly to the water mains, heating water as it’s needed.

Homes which suit combi boilers

Combi boilers are cost effective and energy efficient, with a compact size that’s ideal for smaller properties where space is limited.
Because there’s no need for a water storage tank or a hot water cylinder, a combi boiler can free up space for conversion, storage
and living.

Pros
  • Best suited for two to four people
  • Better suited for homes with two or less bathrooms
  • No need for a water storage tank or hot water cylinder, so can free up space for conversion, storage and living
  • As water is heated only when it is used you won't ever run out of hot water
  • Compact in size, so ideal for smaller properties

Our Combi Boilers

ecoTEC exclusive with Green iQ

The pinnacle of the our boiler range, ecoTEC exclusive carries our unique Green iQ mark, indicating the ultimate in energy efficiency, low consumption and running costs.

Available in

  • Combii
  • Systemi
View ecoTEC exclusive with Green iQ

ecoTEC plus

ecoTEC plus range is available in different power outputs for different lifestyles, all with low energy consumption and premium components that give outstanding performance.

Available in

  • Combii
  • Systemi
  • Regulari
View ecoTEC plus

ecoTEC pro

Providing instant hot water without the need for a tank, the ecoTEC pro combination boiler range is compact enough to fit almost any size of home, and comes in a range of outputs from 24 up to 30kW.

Available in

  • Combii
View ecoTEC pro

ecoFIT pure

ecoFIT pure boilers are available in different power outputs and system types including combi, system and regular, with a space-saving design with flexible fittings for different lifestyles, all with low energy consumption and a premium build for outstanding performance.

Available in

  • Combii
  • Systemi
  • Regulari
View ecoFIT pure

System Boilers

System boilers – also known as sealed system boilers – need a water cylinder to store hot water, which usually sits in an airing cupboard.

In a system boiler, the heating and water systems are built into the boiler itself – there is no need for a water tank like you would need for a regular boiler system.

Homes which suit system boilers

System boilers are ideal for homes with more than one bathroom, and can give a constant supply of hot water to any number of taps at the same time.

Pros
  • Better suited for homes with multiple bathrooms and higher hot water demands
  • System boilers free up space as there is no need for a water tank
  • System boilers are compatible with solar water and heat pump technologies for a lower carbon footprint and lower energy costs
  • Built-in components can make installation quicker and neater

Our System Boilers

ecoTEC exclusive with Green iQ

The pinnacle of the our boiler range, ecoTEC exclusive carries our unique Green iQ mark, indicating the ultimate in energy efficiency, low consumption and running costs.

Available in

  • Combii
  • Systemi
View ecoTEC exclusive with Green iQ

ecoTEC plus

ecoTEC plus range is available in different power outputs for different lifestyles, all with low energy consumption and premium components that give outstanding performance.

Available in

  • Combii
  • Systemi
  • Regulari
View ecoTEC plus

ecoFIT pure

ecoFIT pure boilers are available in different power outputs and system types including combi, system and regular, with a space-saving design with flexible fittings for different lifestyles, all with low energy consumption and a premium build for outstanding performance.

Available in

  • Combii
  • Systemi
  • Regulari
View ecoFIT pure

Regular Boilers

Regular boilers – sometimes known as open vent, heat only or gravity-fed boilers, provide central heating and hot water through a hot water storage cylinder, often found in an airing cupboard, and cold water tank usually found in the loft.

Homes which suit open vent boilers

If your home has multiple bathrooms, open vent boilers are perfect as they can provide a lot of hot water at the same time.
Open vent boilers work well if you are replacing an old open vent heating system, and are ideal if water pressure is low in your area.

 

Pros
  • Open vent boilers can provide enough hot water to serve multiple bathrooms
  • Ideal for larger homes with high hot water demands
  • Open vent boilers are compatible with solar water and heat pump heating systems for a lower carbon footprint and lower energy costs

Our Regular Boilers

ecoTEC plus

ecoTEC plus range is available in different power outputs for different lifestyles, all with low energy consumption and premium components that give outstanding performance.

Available in

  • Combii
  • Systemi
  • Regulari
View ecoTEC plus

ecoFIT pure

ecoFIT pure boilers are available in different power outputs and system types including combi, system and regular, with a space-saving design with flexible fittings for different lifestyles, all with low energy consumption and a premium build for outstanding performance.

Available in

  • Combii
  • Systemi
  • Regulari
View ecoFIT pure

Heating terms explained

A jargon-free guide to phrases in boiler and heating technology

Thermostatic Radiator Valve (TRV)

A TRV is a simple way of adjusting the temperature in individual rooms. It’s an adjustable valve connected to each radiator that allows you to alter the temperature of each room by regulating the flow of hot water to each individual radiator. The TRV regulates the flow depending on how hot or cold the room is. Your installer should assess the condition of your radiators and fittings and may recommend you use TRVs. At least one radiator in your home (usually the room with the room thermostat) won’t have one fitted. This is normal.

Weather compensation control

How cold it is outside influences how much heat your radiators need to maintain your comfort. Weather compensation control is an optional feature available for modern boilers. It works by reacting to the changing temperature outside and intelligently adapting the boiler’s flow temperature to keep it working as efficiently as possible.

Modulation

Sometimes referred to as ‘turn-down ratio’, modulation is the difference between the maximum and the minimum output of a boiler system, and is expressed as a ratio. For example, a 40kW boiler that can operate down to 10kW has a modulation of 1:4 and is highly efficient. The higher the modulation, the more efficient your home. Your heating will deliver a much more reactive and consistent temperature. It will deliver just the right amount of heat, rather than being full-blast or nothing.

Output

The heat output of boilers is measured in kilowatts (kW). Your Vaillant installer will be able to determine the right output for your heating system by carrying out a survey of your home and your own requirements.
With combination boilers, the higher the output, the better hot water delivery, but you will need sufficient mains flow rate. If you have a sealed system or open vent boiler, your boiler’s output will be based on the heat requirement of your radiators, as hot water is stored in a separate cylinder

ErP rating

ErP stands for ‘Energy related Products’, and an ErP rating is an energy efficiency grade which is clearly displayed on a label on your new boiler. The ErP rating helps you to easily see the efficiency of your boiler.

Quiet Mark

Quiet Mark is the international eco award scheme for excellence in quiet product design. Our domestic boilers have been awarded this mark of approval from the UK Noise Abatement Society for their quiet operation.

Green iQ

The Green iQ label is a reliable guide for finding the best product in terms of environmentally friendly, low-cost energy use. Green iQ products work in a highly energy-efficient way and combine climate-friendly heat production with smart, web-based system management.

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