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Boilers Explained

The most important part of the central heating and hot water system. A boiler needs to deliver the maximum output in the most energy-efficient way. Here at Barford Heating Ltd. we list a wide range of energy-efficient boilers available on the market. All our boiler ranges from System, Combi and Conventional boiler.

A System boiler - just like a regular (conventional) boiler - works on the principle of stored hot water. However, a System boiler differs from a regular boiler in some important respects.


Firstly, many of the major individual components of the heating and hot water system are built into a system boiler, which means that installation is quicker, easier and more efficient.


Secondly, the hot water is pumped from the System boiler through the heating system to the radiators and hot water cylinder. This results in a fast response and more economical running costs. The System boiler removes the need for a feed and expansion cistern.

In a System boiler, an expansion vessel replaces the cold tanks, and other integral components of the boiler itself include valves and a system programmer.


  • Far easier to install than Conventional boilers.


  • Costly and complicated to maintain.

In a Conventional boiler, gas jets play onto a cast iron heat exchanger through which water passes to be heated. If used to supply taps, hot water cannot be provided on demand but must be stored - usually in a copper cylinder.

This type of boiler has relatively simple controls and tends to be more reliable as less can go wrong. Energy consumption can be high, but the cost of this is moderated by the low maintenance costs.


Conventional boilers are traditionally referred to as the "Header tank in the loft" type. They have great versatility, in that they can be used in almost any type of property and can be pumped or gravity fed.


  • Very reliable due its simplicity - less things can go wrong.

  • Low maintenance costs.

  • Can be Pumped or Gravity fed.


  • Costly and complicated to install.

  • Low water pressure at the taps nearest the tank.

Conventional Boiler
System Boiler
Combi Boiler

A Combi (or Combination) boiler is an ingenious space-saving idea, and an increasingly popular choice in UK homes. In fact, Combis now account for well over half of all new domestic boilers installed in Britain every year.

A Combi boiler is both a high-efficiency water heater and a central heating boiler combined - hence the name - within one compact unit. Therefore, no separate hot water cylinder is required, offering space-saving within the property.


  • Significant savings on hot water costs.

  • Hot water is delivered through your taps or shower at mains pressure, so you can enjoy powerful showering without he need for a pump.

  • Cheaper installation time and costs, since no tank in the roof space means less pipe work and a shorter installation time.


  • Mains pressure drops when more than one tap is open simultaneously unless a high capacity model is installed.

Cylinders Explained

Conventional and System boiler types both store hot water in cylinders. A hot water cylinder is commonly used to ensure enough stored hot water is available on demand for baths, showers and kitchen use.


The hot water cylinder comes in different sizes depending on the hot water demand of a property. Hot water cylinders come in different forms, depending on the way each is supplied with water, these forms are Vented, Unvented and Solar.

Vented cylinder

With open vented systems, a large volume of cold water is stored in a header tank located at a higher level than the cylinder, usually in the attic. The water storage cylinder - usually located in the airing cupboard - is fed at the base of the cylinder by the header tank.


Water pressure and flow within the system is driven by gravity i.e. the weight of the stored water in the header tank is usually sufficient to push water down the pipe that feeds the water storage cylinder and back up to any tap or shower outlet, providing it is lower than the stored water level.

When the water is heated, it rises to the top of the cylinder where it can be drawn off through the hot water supply pipes and tap or shower outlets, the water is automatically replaced in the cylinder via the header tank.

Heating causes the water within the cylinder to expand. A vent pipe allows a safe route for excess pressure, air bubbles and steam should the system overheat. It runs from the top of the cylinder back up to the cold water storage header tank where its open vent is located just above the water level.


  • The lowest cost option for both installation and maintenance.

  • Provides access to a supply of water in the event the mains supply needs to be turned off.


  • Because it relies on gravity, the height of the cold water tank dictates the water pressure to the taps and shower. This sometimes leads to lower pressure upstairs than downstairs, which can usually be alleviated by installing an additional pump.

Unvented cylinder

Unvented cylinders are mains pressure hot water storage systems that provide a highly efficient way of storing and distributing domestic hot water at mains pressure throughout your home.


These cylinders are not open to the atmosphere via the cylinder’s vent pipe and the cylinder’s cold feed pipe from the cold water storage cistern/tank. These mains pressure unvented cylinders provide quicker heat recovery than the low pressure open vented cylinders.


Because water is supplied from the mains supply and not from a cold water storage cistern/tank, the flow rate and water pressure from an unvented cylinder at the outlets is much greater than from the storage fed open vented cylinder.


  • Because no water storage tank is needed, Unvented cylinders take up less space, and so have greater flexibility in where they can be installed.

  • Stronger pressure is provided all over the house, due to taking their water direct from the mains supply as opposed to a separate storage tank.

  • Eliminates problems associated with a water tank, such as contamination or freezing.


  • Higher installation and maintenance costs due to the increased complexity of the technology and components used.

  • If the mains supply needs to be turned off for some reason, you lose access to hot water.

  • There can be compatibility issues when choosing some modern mixer taps or power showers.


Radiators are commonly used to heat buildings. In a central heating system, hot water - or sometimes steam - is generated in a central boiler and circulated by pumps through radiators within the building.


There are two types of radiator - Single-pipe and double-pipe.

Single-pipe radiators work with steam, while the double-pipe radiators work with either steam or hot water.

We have a wide range available to suit most needs and tastes. From small space-saving, low output models; to larger, more powerful models. From functional, unobtrusive models to something a bit more eye-catching. Whatever your needs, Barford's will have the right solution for you, so contact us today.

Central Heating Boiler
Central Heating Boiler & Plumbing
Combi Boiler Installation
Joule Central Heating Cylinder
Towel Heater Installation
Vented Central Heaing Cylinder
Central Heating Boiler installation
Radiator Installation

Water Pumps

Grundfos Central Heating Pump

Central Heating Pumps are the "beating heart" of every Central Heating System. Their function is to drive water round the heating system.


Pumps come in different sizes for different applications. We offer a wide range of pumps for both commercial and domestic applications.


We stock DAB, Grundfos and other brands of pump. We can source all the latest pumps including A-Rated models if not listed.

If you need a price - or just some advice on the most suitable pump for your heating system - then please just contact us today.

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