Tag Archives: system boilers vs combi boilers

Picking the Right Boiler

boiler adviceChoosing the Right Boiler for your Home

One of the major decisions we encountered came in the form of choosing the right kind of boiler for our project. A new boiler system represents a major investment and we felt it was crucial that we got it right first time in order to save us the bother of some rather costly financial headaches down the line. It’s my intention to share with you my thought process and hopefully to be able to inform and educate on the subject. First of all, an overview of the main options we considered with http://www.gasengineerinpoole.co.uk/:

Combi Boilers

How it works:

Combis work as sealed systems, providing hot water for both the taps and central heating system, heating the water directly from the mains when it is necessary – this means there’s no requirement for any hot water storage cylinder, or a cistern inside roof space.

Benefits: Combis are quicker, easier and more cost-effective to install than system boilers, and also space saving due to the lack of a cylinder or cistern. Water is provided at mains pressure, so you’re able to benefit from a stronger (although not ‘power’) shower.

Disadvantages: It’s a priority system, therefore it just handles one heating requirement at a time to an acceptable standard. While fine for small families with one bathroom, bigger families will experience poor flow rates whenever multiple outlets are utilized at the same time. Functionality is furthermore reliant on the diameter of the pipe entering into the property: when it’s lower than 22mm, then a combi is definitely a bad option.

Despite the convenience of combi boilers in terms of installation and space saving, we felt that the advantages outweighed the disadvantages as we will often require multiple simultaneous heating requirements, rendering the combi boiler a non-starter.

System Boilers

How they work:

System boilers are designed for sealed heating systems, but unlike combis they operate on the theory of holding hot water inside a cylinder, to enable them to supply numerous outlets simultaneously at mains pressure. There’s no need for a cistern inside the loft and the expansion vessel is built in.

Advantages: Ideal for large homes with bigger demands, and as they already have most of their major components built in (i.e. expansion vessel and pump), installation is faster, more cost-effective and neater. Flow rates are typically high for the reason that water is provided at mains pressure, not to mention hot water is instantaneous.

Disadvantages: Is going to use up all your hot water when overused. A number of fitters assert they are more technical and prone to complications compared with regular boilers, for instance pressure loss.

Regular/Conventional Boiler

regular boiler layout
The way they work:

Regular boilers are currently generally obtained as replacements for homes using an open-vented heating system (i.e. supplied by means of a feed and expansion cistern inside the roof space, which means the system is open to air). Just like system boilers, they function on the principle of stored water and require an independent hot water cylinder.

Advantages: The water out of the taps is going to be at a good flow rate (not to be confused with pressure) and also hot water is provided instantaneously. It’s the most suitable setup for a ‘power’ shower, which demands a cold water feed from your cistern as well as a distinct electric pump.

Drawbacks: They’re more costly to install, needing more parts and pipework, as well as requiring extra space. They could experience low pressure when the cistern isn’t placed high enough, this means additional shower boosters may be necessary. Hot water can run out.

We felt that the extra space required for this set up was an unacceptable trade off and therefore a conventional boiler wasn’t a serious consideration for us.

In the end we opted for the system boiler as we wanted instantaneous hot water without the huge space demands of a conventional boiler. It’s important for you to weigh up the pros and cons of the aforementioned heating systems and apply them to your own situation – a system boiler wouldn’t be necessary for a smaller household for instance. Learn more about boilers for your home here: http://www.gasengineerinpoole.co.uk/boiler-installation-poole/

or take a look at the video below from Which?