There are many considerations when considering whether to have a combination boiler or a standard boiler?  A combination boiler gives central heating and heats water instantaneously to provide Domestic Hot Water (DHW) at the taps. This eliminates the need to have a separate DHW cylinder in an airing cupboard and so can provide space where it’s limited.

Pros: DHW is provided only when required in only the required quantity.  Space is freed up where a cylinder may have been.  The plumbing for the boiler is easy meaning they are often installed on new builds.

Cons: If your boiler develops a fault you will have no heating and more importantly NO Domestic Hot Water.  Don’t you wish you had a cylinder so you could turn on that immersion heater?!  They can be more unreliable than a standard boiler as they have more components, so more likely to go wrong. Over a long period of time they are more likely to go wrong so maintenance charges are likely to be greater.

Standard boilers use a cylinder to store an amount of DHW.  They are also known as ‘heat only’ boilers.

Pros:  They have relatively few components and so are inherently more reliable than a combination boiler.  If they break down you will lose central heating but will still have a cylinder with immersion heater for your DHW.

Cons:  They heat a large amount of water when required (normally the whole cylinder, typically 100-200 litres).  The water may be greater than your needs and with cylinder heat losses you could be wasting energy.

At SHAPE Contractor we normally advise to fit a standard  boiler and keep the cylinder if at all possible and room permits. We never take out a standard boiler and replace with a combi unless the client insists that is what they require or there is a combi already in place that is beyond repair.