Viva Gas Energy Efficiency Matters

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Understanding your system

Understanding what type of boiler system is currently installed into a property doesn’t have to be difficult. Viva Gas has simplified the main points so that the correct system can be installed in relation to the space available, flow rate and the amount of bathrooms the system feeds (see our new boiler installation page).

General points to know about a system

  • The flow rate is measured by the water pressure entering a property plus how fast the boiler is able to heat the water at the temperature set on installation
  • Flow rate is always determined by the water pressure not by the power of the boiler
  • The more power a new boiler has, the faster the boiler is able to heat water
  • Your New condensing technology means as much heat as possible is converted into fuel for your home. By condensing, your boiler will ensure at least 90p in every £1 you spend on gas or oil will be converted into heat for your home comfort*

*Worcester Bosch

Boiler System A – Combination boiler heating system A.K.A the ‘Combi Boiler’

A combi boiler is a single compact unit that supplies both heating and hot water.

Benefits of a combi boiler system

  • No loft space required
  • Can be installed as a unit in a kitchen
  • No hot or cold water cylinders required
  • Less pipework required – lower installation cost

How does a combination system work?

combi boilerA combi boilers heats water over a heat exchanger directly from the cold mains at mains pressure, if you have good mains pressure you will benefit from a power shower experience.

A combi boiler is always on standby hence hot water is always available 24/7.

Unfortunately the combi boiler system cannot provide hot water and central heating simultaneously; priority is always given to the source to tap in the first instance.

Boiler System B – Regular boiler heating system A.K.A the traditional, conventional or heat only boiler

A regular boiler requires a hot water cylinder and a cold water tank in the loft.

Benefits of a Regular boiler system

  • Suitable for properties with more than one bathroom
  • Suitable for low water pressure
  • Compatible with solar water heating systems
  • Reliable and cheap to install


How does a regular boiler system work?

regular boiler systemHeated water which is stored in large cylinders or tanks is fed directly to outlets or a central heating system, because the water is stored there should be no loss of pressure when running sources (central heating or taps) simultaneously.

If there is a breakdown on a regular boiler system there should be no loss of hot water as most hot water tanks are installed with an electric heater

There are 2 types of regular systems; unvented and vented. An unvented hot water system operates under mains pressure so no cold water header tank is necessary. A vented system is a condensing open vent boiler system (see general points).

A large amount of space is required in a loft for a regular boiler installation as a hot water cylinder and cold water tank is always required. Hot water stock does need replenishing which can take between 60-80 minutes to reheat.

Boiler System C System boiler heating system

A System boiler which has a hot water cylinder built into the boiler itself.

Benefits of a System boiler

  • Compatible with a solar hot water systems
  • No cold water tank space required in the loft
  • Suitable for properties with more than 1 bathroom
  • A quick installation process as hot water components are already included in the boiler
  • Systems and taps can be used simultaneously with no loss of pressure

How does a System boiler system work?

system boiler diagramSystem Boilers are similar to regular boilers apart from, an expansion vessel and a pressure release valve is included in the boiler components. The pressure release valve is used to release water if the pressure gets too high.

A system boiler does need an insulated hot water cylinder installed in the loft; the cylinder is insulated so heat from the tank does not escape. The boiler does need to be accessible hence the boilers are usually placed in large cupboards. Once the tank of hot water has been utilised there is a wait time until the boiler produces hot water again, this depends on the timer settings on the system installation.


Get a Free Quote

If you would like to receive a quote, please fill in the form below. You can also call Viva Gas on 08006 123177 Monday to Friday 9-5pm.

"After discovering the bottom part of some of my radiators were never getting warm, I rang Viva Gas for some advice. They were very helpful and sent out an engineer straight away who power flushed my central heating system. It’s now working like it is brand new." - Mrs Swallow

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